De-escalation of axillary treatment in the event of a positive sentinel lymph node biopsy in cT1-2 N0 breast cancer treated with mastectomy: nationwide registry study (BOOG 2013-07)

BACKGROUND

Trials have demonstrated the safety of omitting completion axillary lymph node dissection in patients with cT1-2 N0 breast cancer operated with breast-conserving surgery who have limited metastatic burden in the sentinel lymph node. The aim of this registry study was to provide insight into the oncological safety of omitting completion axillary treatment in patients operated with mastectomy who have limited-volume sentinel lymph node metastasis.

METHODS

Women diagnosed in 2013-2014 with unilateral cT1-2 N0 breast cancer treated with mastectomy, with one to three sentinel lymph node metastases (pN1mi-pN1a), were identified from the Netherlands Cancer Registry, and classified by axillary treatment: no completion axillary treatment, completion axillary lymph node dissection, regional radiotherapy, or completion axillary lymph node dissection followed by regional radiotherapy. The primary endpoint was 5-year regional recurrence rate. Secondary endpoints included recurrence-free interval and overall survival, among others.

RESULTS

In total, 1090 patients were included (no completion axillary treatment, 219 (20.1%); completion axillary lymph node dissection, 437 (40.1%); regional radiotherapy, 327 (30.0%); completion axillary lymph node dissection and regional radiotherapy, 107 (9.8%)). Patients in the group without completion axillary treatment had more favourable tumour characteristics and were older. The overall 5-year regional recurrence rate was 1.3%, and did not differ significantly between the groups. The recurrence-free interval was also comparable among groups. The group of patients who did not undergo completion axillary treatment had statistically significantly worse 5-year overall survival, owing to a higher percentage of non-cancer deaths.

CONCLUSION

In this registry study of patients with cT1-2 N0 breast cancer treated with mastectomy, with low-volume sentinel lymph node metastasis, the 5-year regional recurrence rate was low and comparable between patients with and without completion axillary treatment.

Prognostic effect of nodal status before and after neoadjuvant chemotherapy in breast cancer: a Dutch population-based study

PURPOSE

In breast cancer, neoadjuvant chemotherapy (NAC) can downstage the nodal status, and can even result in a pathological complete response, which is associated with improved prognosis. This study aimed to determine the prognostic effect of nodal status before and after NAC.

METHODS

Women with breast cancer treated with NAC were selected from the Netherlands Cancer Registry if diagnosed between 2005 and 2019, and classified based on nodal status before NAC: node-negative (cN0), or node-positive based on fine needle aspiration cytology or core needle biopsy (cN+). Subgroups were based on nodal status after NAC: absence (ypN0) or presence (ypN+) of nodal disease. Five-year overall survival (OS) was assessed with Kaplan-Meier survival analyses, also per breast cancer molecular subtype. To adjust for potential confounders, multivariable analyses were performed.

RESULTS

A total of 6,580 patients were included in the cN0 group, and 11,878 in the cN+ group. The 5-year OS of the cN0ypN0-subgroup was statistically significant better than that of the cN+ypN0-subgroup (94.4% versus 90.1%, p < 0.0001). In cN0 as well as cN+ disease, ypN+ had a statistically significant worse 5-year OS compared to ypN0. For hormone receptor (HR)+ human epidermal growth factor receptor 2 (HER2)-, HR+ HER2+, HR-HER2+, and triple negative disease, respectively, 5-year OS in the cN0ypN+-subgroup was 89.7%, 90.4%, 73.7%, and 53.6%, and in the cN+ypN+-subgroup 84.7%, 83.2%, 61.4%, and 48.8%. In multivariable analyses, cN+ and ypN+ disease were both associated with worse OS.

CONCLUSION

This study suggests that both cN-status and ypN-status, and molecular subtype should be considered to further improve prognostication.

Systematic review of targeted axillary dissection in node-positive breast cancer treated with neoadjuvant systemic therapy: variation in type of marker and timing of placement

BACKGROUND

In node-positive (cN+) breast cancer treated with neoadjuvant systemic therapy, combining sentinel lymph node biopsy and targeted lymph node excision, that is targeted axillary dissection, increases accuracy. Targeted axillary dissection procedures differ in terms of the targeted lymph node excision technique. This systematic review aimed to provide an overview of targeted axillary dissection procedures regarding definitive marker type and timing of placement: before neoadjuvant systemic therapy (1-step procedure) or after neoadjuvant systemic therapy adjacent to a clip placed before the neoadjuvant therapy (2-step procedure).

METHODS

PubMed and Embase were searched, to 4 July 2023, for RCTs, cohort studies, and case-control studies with at least 25 patients. Studies of targeted lymph node excision only (without sentinel lymph node biopsy), or where intraoperative localization of the targeted lymph node was not attempted, were excluded. For qualitative synthesis, studies were grouped by definitive marker and timing of placement. The targeted lymph node identification rate was reported. Study quality was assessed using a National Institutes of Health quality assessment tool.

RESULTS

Of 277 unique records, 51 studies with a total of 4512 patients were included. Six definitive markers were identified: wire, 125I-labelled seed, 99mTc, (electro)magnetic/radiofrequency markers, black ink, and a clip. Fifteen studies evaluated one-step procedures, with the identification rate of the targeted lymph node at surgery varying from 8 of 13 to 47 of 47. Forty-one studies evaluated two-step procedures, with the identification rate of the clipped targeted lymph node on imaging after neoadjuvant systemic therapy varying from 49 to 100%, and the identification rate of the targeted lymph node at surgery from 17 of 24 to 100%. Most studies (40 of 51) were rated as being of fair quality.

CONCLUSION

Various targeted axillary dissection procedures are used in clinical practice. Owing to study heterogeneity, the optimal targeted lymph node excision technique in terms of identification rate and feasibility could not be determined. Two-step procedures are at risk of not identifying the clipped targeted lymph node on imaging after neoadjuvant systemic therapy.

Quality assurance of radiation therapy after breast-conserving surgery among patients in the BOOG 2013-08 trial

BACKGROUND AND PURPOSE

In the BOOG 2013-08 trial (NCT02271828), cT1-2N0 breast cancer patients were randomized between breast conserving surgery with or without sentinel lymph node biopsy (SLNB) followed by whole breast radiotherapy (WBRT). While awaiting primary endpoint results (axillary recurrence rate), this study aims to perform a quality assurance analysis on protocol adherence and (incidental) axillary radiation therapy (RT) dose.

MATERIALS AND METHODS

Patients were enrolled between 2015 and 2022. Data on prescribed RT and (in 25% of included patients) planning target volumes (PTV) parameters were recorded for axillary levels I-IV and compared between treatment arms. Multivariable linear regression analysis was performed to determine prognostic variables for incidental axillary RT dose.

RESULTS

1,439/1,461 included patients (98.5%) were treated according to protocol and 87 patients (5.9%) received regional RT (SLNB 10.9%, no-SLNB 1.5 %). In 326 patients included in the subgroup analysis, the mean incidental PTV dose at axilla level I was 59.5% of the prescribed breast RT dose. In 5 patients (1.5%) the mean PTV dose at level I was ≥95% of the prescribed breast dose. No statistically or clinically significant differences regarding incidental axillary RT dose were found between treatment arms. Tumour bed boost (yes/no) was associated with a higher incidental mean dose in level I (R2 = 0.035, F(6, 263) = 1.532, p 0.168).

CONCLUSION

The results indicate that RT-protocol adherence was high, and that incidental axillary RT dose was low in the BOOG 2013-08 trial. Potential differences between treatmentarms regarding the primary endpoint can thus not be attributed to different axillary radiation doses.

Germinal centres within tumour positive sentinel lymph nodes are positively associated with tumour infiltrating lymphocytes and tertiary lymphoid structures in breast cancer

BACKGROUND

Stromal tumour infiltrating lymphocytes (sTILs) and presence of tertiary lymphoid structures have been proposed as indicators of tumour-related immune response in breast cancer. An increased number of germinal centres (GCs) in lymph nodes is considered a sign of humoral immune reactivity.

AIMS

It is unclear whether a relationship exists between number and size of GCs within tumour positive sentinel lymph nodes (SLNpos), sTILs and tertiary lymphoid structures within matched primary breast cancer and breast cancer subtype.

METHODS

Axillary SLNpos from 175 patients with breast cancer were manually contoured in digitized haematoxylin and eosin stained sections. Total SLN area, GC number and GC area were measured in SLNpos with the largest metastatic area. To correct for SLN size, GC number and GC area were divided by SLN area. sTILs and presence of tertiary lymphoid structures were assessed in the primary breast cancer.

RESULTS

A higher GC number and larger GC area were found in patients with high sTILs (≥2%) (both P < 0.001) and in patients with presence of tertiary lymphoid structures (PGC number = 0.034 and PGC area = 0.016). Triple negative and HER2-positive (N = 45) breast cancer subtypes had a higher GC number and higher sTILs compared to hormone receptor positive, HER2-negative breast cancer (N = 130) (PGC number < 0.001 and PsTILs= 0.001).

CONCLUSION

This study suggests GCs measured within SLNpos might be useful indicators of the humoral anti-tumour immune response in breast cancer. Future studies are needed investigating underlying biological mechanisms and prognostic value of GCs in SLNs.

Gene expression profiles in clinically T1-2N0 ER+HER2- breast cancer patients treated with breast-conserving therapy: their added value in case sentinel lymph node biopsy is not performed

PURPOSE

Omitting sentinel lymph node biopsy (SLNB) in breast cancer treatment results in patients with unknown positive nodal status and potential risk for systemic undertreatment. This study aimed to investigate whether gene expression profiles (GEPs) can lower this risk in cT1-2N0 ER+ HER2- breast cancer patients treated with BCT.

METHODS

Patients were included if diagnosed between 2011 and 2017 with cT1-2N0 ER+ HER2- breast cancer, treated with BCT and SLNB, and in whom GEP was applied. Adjuvant chemotherapy recommendations based on clinical risk status (Dutch breast cancer guideline of 2020 versus PREDICT v2.1) with and without knowledge on SLNB outcome were compared to GEP outcome. We examined missing adjuvant chemotherapy indications, and the number of GEPs needed to identify one patient at risk for systemic undertreatment.

RESULTS

Of 3585 patients, 2863 (79.9%) had pN0 and 722 (20.1%) pN + disease. Chemotherapy was recommended in 1354 (37.8% guideline-2020) and 1888 patients (52.7% PREDICT). Eliminating SLNB outcome (n = 722) resulted in omission of chemotherapy recommendation in 475 (35.1% guideline-2020) and 412 patients (21.8% PREDICT). GEP revealed genomic high risk in 126 (26.5% guideline-2020) and 82 patients (19.9% PREDICT) in case of omitted chemotherapy recommendation in the absence of SLNB. Extrapolated to the whole group, this concerns 3.5% and 2.3%, respectively, resulting in the need for 28-44 GEPs to identify one patient at risk for systemic undertreatment.

CONCLUSION

If no SLNB is performed, clinical risk status according to the guideline of 2020 and PREDICT predicts a very low risk for systemic undertreatment. The number of GEPs needed to identify one patient at risk for undertreatment does not justify its standard use.

Fecal levels of SCFA and BCFA during capecitabine in patients with metastatic or unresectable colorectal cancer

BACKGROUND

Gut bacteria-derived short-chain fatty acids (SCFA) and branched-chain fatty acids (BCFA) are considered to have beneficial metabolic, anti-inflammatory as well as anti-carcinogenic effects. Previous preclinical studies indicated bidirectional interactions between gut bacteria and the chemotherapeutic capecitabine or its metabolite 5-FU. This study investigated the effect of three cycles of capecitabine on fecal SCFA and BCFA levels and their associations with tumor response, nutritional status, physical performance, chemotherapy-induced toxicity, systemic inflammation and bacterial abundances in patients with colorectal cancer (CRC).

METHODS

Forty-four patients with metastatic or unresectable CRC, scheduled for treatment with capecitabine (± bevacizumab), were prospectively enrolled. Patients collected a fecal sample and completed a questionnaire before (T1), during (T2) and after (T3) three cycles of capecitabine. Tumor response (CT/MRI scans), nutritional status (MUST score), physical performance (Karnofsky Performance Score) and chemotherapy-induced toxicity (CTCAE) were recorded. Additional data on clinical characteristics, treatment regimen, medical history and blood inflammatory parameters were collected. Fecal SCFA and BCFA concentrations were determined by gas chromatography-mass spectrometry (GC-MS). Gut microbiota composition was assessed using 16S rRNA amplicon sequencing.

RESULTS

Fecal levels of the SCFA valerate and caproate decreased significantly during three cycles of capecitabine. Furthermore, baseline levels of the BCFA iso-butyrate were associated with tumor response. Nutritional status, physical performance and chemotherapy-induced toxicity were not significantly associated with SCFA or BCFA. Baseline SCFA correlated positively with blood neutrophil counts. At all time points, we identified associations between SCFA and BCFA and the relative abundance of bacterial taxa on family level.

CONCLUSIONS

The present study provided first indications for a potential role of SCFA and BCFA during capecitabine treatment as well as implications for further research.

TRIAL REGISTRATION

The current study was registered in the Dutch Trial Register (NTR6957) on 17/01/2018 and can be consulted via the International Clinical Trial Registry Platform (ICTRP).

The prognostic and predictive effect of body mass index in hormone receptor-positive breast cancer

BACKGROUND

Obesity has been associated with an adverse prognosis and reduced efficacy of endocrine therapy in patients with hormone receptor-positive (HR+) breast cancer (BC). This study determines the prognostic and predictive effect of body mass index (BMI) on the disease-free survival (DFS) of postmenopausal HR+ BC patients.

METHODS

Patients were identified from the DATA study (NCT00301457), a randomized controlled trial evaluating the efficacy of 6 vs 3 years of anastrozole after 2 to 3 years of adjuvant tamoxifen in postmenopausal women with HR+ BC. Patients were classified as normal weight (BMI: 18.5-24.9 kg/m2), overweight (25.0-29.9 kg/m2), or obese (≥30.0 kg/m2). The primary endpoint was DFS, evaluated from randomization (prognostic analyses) or 3 years after randomization onwards (predictive analyses; aDFS) using multivariable Cox regression analyses. P-values were 2-sided.

RESULTS

This study included 678 normal weight, 712 overweight, and 391 obese patients. After a median follow-up of 13.1 years, overweight and obesity were identified as negative prognostic factors for DFS (hazard ratio (HR) = 1.16; 95% confidence interval (CI) = 0.97 to 1.38 and HR = 1.26; 95% CI = 1.03 to 1.54, respectively). The adverse prognostic effect of BMI was observed in women aged younger than 60 years, but not in women aged 60 years or older (P-interaction = .009). The effect of extended anastrozole on aDFS was similar in normal weight (HR = 1.00; 95% CI = 0.74 to 1.35), overweight (HR = 0.74; 95% CI = 0.56 to 0.98), and obese patients (HR = 0.97; 95% CI = 0.69 to 1.36) (P-interaction = .24).

CONCLUSION

In this study among 1781 HR+ BC patients, overweight and obesity were adverse prognostic factors for DFS. BMI did not impact the efficacy of extended anastrozole.

The prognostic value of the histological shape of tumor negative sentinel nodes in breast cancer

Introduction

Sentinel lymph node (SLN) metastasis is an important predictor of prognosis in breast cancer (BC) patients, guiding treatment decisions. However, patients with the same BC subtype and tumor negative SLN (SLNneg) can have different survival outcomes. We hypothesized that the host anti-tumor immune reaction in SLNneg is important and results in morphometrically measurable changes in SLN size or shape which are related to patient prognosis.

Methods

Surface area, circumference, long axis and short axis were histologically measured in 694 SLNneg from 356 cases of invasive BC and 67 ductal carcinoma in situ cases. The area occupied by fat was categorized as less or more than 50%. The long to short axis (L/S) ratio was calculated. The relationship between SLNneg morphometries and clinicopathological variables like tumor-infiltrating lymphocytes (TILs) within the primary tumor, as well as prognosis at 10 years follow up were analyzed.

Results

The mean SLNneg surface area was 78.7mm2, circumference 40.3mm, long axis 13.1mm, short axis 8.2mm and L/S ratio 1.7. Larger surface area, long axis and short axis, including age >55 years were associated with higher body mass index (BMI) and SLN fat over 50% (p<0.003). In invasive BC, a high SLNneg L/S ratio (≥1.9) was related to poorer disease-free (HR=1.805, 95%CI 1.182-2.755, p=0.006) and overall (HR=2.389, 95%CI 1.481-3.851, p<0.001) survival. A low SLNneg L/S ratio (<1.9) was associated with high TILs in the primary BC (≥10%) (p=0.005). However a high TIL count was not of prognostic relevance.

Conclusions

This is the first study to suggest that morphometric characteristics of axillary SLNneg, like L/S ratio, could be used to predict prognosis in patients with SLNneg invasive BC of all subtypes. The association between low L/S ratio and high TILs suggest that SLN shape is related to immunological functioning of the SLN and could be used in addition to TIL evaluation. Regarding the dubious role of TILs in hormone receptor positive breast cancer, SLNneg morphometry to gain information about host immune status could especially be of benefit in this subtype. Further studies are warranted to better understand the underlying biological mechanisms.

Imaging findings for response evaluation of ductal carcinoma in situ in breast cancer patients treated with neoadjuvant systemic therapy: a systematic review and meta-analysis

OBJECTIVES

In approximately 45% of invasive breast cancer (IBC) patients treated with neoadjuvant systemic therapy (NST), ductal carcinoma in situ (DCIS) is present. Recent studies suggest response of DCIS to NST. The aim of this systematic review and meta-analysis was to summarise and examine the current literature on imaging findings for different imaging modalities evaluating DCIS response to NST. More specifically, imaging findings of DCIS pre- and post-NST, and the effect of different pathological complete response (pCR) definitions, will be evaluated on mammography, breast MRI, and contrast-enhanced mammography (CEM).

METHODS

PubMed and Embase databases were searched for studies investigating NST response of IBC, including information on DCIS. Imaging findings and response evaluation of DCIS were assessed for mammography, breast MRI, and CEM. A meta-analysis was conducted per imaging modality to calculate pooled sensitivity and specificity for detecting residual disease between pCR definition no residual invasive disease (ypT0/is) and no residual invasive or in situ disease (ypT0).

RESULTS

Thirty-one studies were included. Calcifications on mammography are related to DCIS, but can persist despite complete response of DCIS. In 20 breast MRI studies, an average of 57% of residual DCIS showed enhancement. A meta-analysis of 17 breast MRI studies confirmed higher pooled sensitivity (0.86 versus 0.82) and lower pooled specificity (0.61 versus 0.68) for detection of residual disease when DCIS is considered pCR (ypT0/is). Three CEM studies suggest the potential benefit of simultaneous evaluation of calcifications and enhancement.

CONCLUSIONS AND CLINICAL RELEVANCE

Calcifications on mammography can remain despite complete response of DCIS, and residual DCIS does not always show enhancement on breast MRI and CEM. Moreover, pCR definition effects diagnostic performance of breast MRI. Given the lack of evidence on imaging findings of response of the DCIS component to NST, further research is demanded.

KEY POINTS

• Ductal carcinoma in situ has shown to be responsive to neoadjuvant systemic therapy, but imaging studies mainly focus on response of the invasive tumour. • The 31 included studies demonstrate that after neoadjuvant systemic therapy, calcifications on mammography can remain despite complete response of DCIS and residual DCIS does not always show enhancement on MRI and contrast-enhanced mammography. • The definition of pCR has impact on the diagnostic performance of MRI in detecting residual disease, and when DCIS is considered pCR, pooled sensitivity was slightly higher and pooled specificity slightly lower.

MSCDA: Multi-level semantic-guided contrast improves unsupervised domain adaptation for breast MRI segmentation in small datasets

Deep learning (DL) applied to breast tissue segmentation in magnetic resonance imaging (MRI) has received increased attention in the last decade, however, the domain shift which arises from different vendors, acquisition protocols, and biological heterogeneity, remains an important but challenging obstacle on the path towards clinical implementation. In this paper, we propose a novel Multi-level Semantic-guided Contrastive Domain Adaptation (MSCDA) framework to address this issue in an unsupervised manner. Our approach incorporates self-training with contrastive learning to align feature representations between domains. In particular, we extend the contrastive loss by incorporating pixel-to-pixel, pixel-to-centroid, and centroid-to-centroid contrasts to better exploit the underlying semantic information of the image at different levels. To resolve the data imbalance problem, we utilize a category-wise cross-domain sampling strategy to sample anchors from target images and build a hybrid memory bank to store samples from source images. We have validated MSCDA with a challenging task of cross-domain breast MRI segmentation between datasets of healthy volunteers and invasive breast cancer patients. Extensive experiments show that MSCDA effectively improves the model's feature alignment capabilities between domains, outperforming state-of-the-art methods. Furthermore, the framework is shown to be label-efficient, achieving good performance with a smaller source dataset. The code is publicly available at https://github.com/ShengKuangCN/MSCDA.

Pathologic complete response of ductal carcinoma in situ to neoadjuvant systemic therapy in HER2-positive invasive breast cancer patients: a nationwide analysis

PURPOSE

Ductal carcinoma in situ (DCIS) is present in more than half of HER2-positive invasive breast cancer (IBC). Recent studies show that DCIS accompanying HER2-positive IBC can be completely eradicated by neoadjuvant systemic therapy (NST). Our aim was to determine the percentage of pathologic complete response of the DCIS component in a nationwide cohort and to assess associated clinicopathologic variables. Furthermore, the impact on surgical treatment after NST was investigated.

METHODS

Women diagnosed with HER2-positive IBC, treated with NST and surgery, between 2010 and 2020, were selected from the Netherlands Cancer Registry. Pre-NST biopsy and postoperative pathology reports were obtained from the Dutch Nationwide Pathology Databank and assessed for the presence of DCIS. Clinicopathologic factors associated with DCIS response were assessed using logistic regression analyses.

RESULTS

A DCIS component was present in the pre-NST biopsy in 1403 (25.1%) of 5598 included patients. Pathologic complete response of the DCIS component was achieved in 730 patients (52.0%). Complete response of DCIS occurred more frequently in case of complete response of IBC (63.4% versus 33.8%, p < 0.001). ER-negative IBC (OR 1.79; 95%CI 1.33-2.42) and more recent years of diagnosis (2014-2016 OR 1.60; 95%CI 1.17-2.19, 2017-2019 OR 1.76; 95%CI 1.34-2.34) were associated with DCIS response. Mastectomy rates were higher in IBC+DCIS compared to IBC (53.6% versus 41.0%, p < 0.001).

CONCLUSION

Pathologic complete response of DCIS occurred in 52.0% of HER2-positive IBC patients and was associated with ER-negative IBC and more recent years of diagnosis. Future studies should investigate imaging evaluation of DCIS response to improve surgical decision making.

Abstract 4380: Pre- and postoperative fecal microbiota and its association with complications after surgery in colon cancer patients

Introduction: Postoperative complications impact morbidity and mortality of colon cancer patients. Emerging evidence suggests that intestinal microbiota might play a critical role in the development of postoperative complications after gastrointestinal surgery. Here, we studied changes in fecal microbiota composition comparing samples collected before and after colon cancer surgery. Moreover, we examined whether the microbiota composition before surgery was associated with postoperative complications, and we explored potential determinants of the preoperative microbiota in colon cancer patients.

Methods: For this study, two fecal samples were provided by 78 patients with colon cancer. The first (preoperative) sample was collected shortly after diagnosis and before (median and interquartile (IQR) range of 4 (2-6) days) colon cancer surgery. The second (postoperative) sample was collected approximately 6 weeks (median and IQR of 42 (37-47) days) after surgery and before start of adjuvant chemotherapy (whenever applicable). Based on 16S ribosomal RNA gene amplicon sequencing, the fecal microbiota diversity and composition were determined. Preoperative microbiota composition of patients who developed postoperative complications in the 30 days following surgery (n=18, 23%) was compared to those who did not (n=60, 77%) using univariate and multivariate analyses. Explorative random forest analyses were conducted to identify predictors of complication status, with relative abundance of the core genera, sex, age, fecal calprotectin levels, dietary fiber intake, body mass index, smoking status, ASA classification, cancer stage and tumor location being considered as potential predictors.

Results: After surgery, microbial alpha diversity was reduced compared to the preoperative situation, whereas compositional changes over time only reached statistical significance for Lachnospiraceae NK4A136 and Coprococcus 1, which both decreased in relative abundance after surgery. Already before the start of surgery, relative abundance of the genera Bacteroides (10% vs 6%) and Lachnoclostridium (0.6% vs 0.2%) appeared to be higher in patients with complications versus those with uncomplicated recovery. In a prediction analysis, current smoking and relative abundance of Lachnoclostridium were identified as most profound predictors of complication status. Fecal calprotectin levels and current smoking status explained most (together 6%) of the overall variation in microbiota composition before surgery.

Conclusion: In this study, higher relative abundances of the genera Bacteroides and Lachnoclostridium before surgery were associated with postoperative complications in patients with colon cancer. Future studies should expand on the potential causal and pathogenic routes underlying these observations.

Citation Format: Dieuwertje E. Kok, Jannigje G. Kers, Hendriek C. Boshuizen, Niels Klaassen, Henk K. van Halteren, Flip M. Kruyt, Marjolein L. Smidt, Johannes H. De Wilt, Annemarie Boleij, Ellen Kampman, Erwin G. Zoetendal. Pre- and postoperative fecal microbiota and its association with complications after surgery in colon cancer patients. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4380.

The influence of receptor expression and clinical subtypes on baseline [18F]FDG uptake in breast cancer: systematic review and meta-analysis

BACKGROUND

To quantify the relationship between [18F]FDG uptake of the primary tumour measured by PET-imaging with immunohistochemical (IHC) expression of ER, PR, HER2, Ki-67, and clinical subtypes based on these markers in breast cancer patients.

METHODS

PubMed and Embase were searched for studies that compared SUVmax between breast cancer patients negative and positive for IHC expression of ER, PR, HER2, Ki-67, and clinical subtypes based on these markers. Two reviewers independently screened the studies and extracted the data. Standardized mean differences (SMD) and 95% confidence intervals (CIs) were estimated by using DerSimonian-Laird random-effects models. P values less than or equal to 5% indicated statistically significant results.

RESULTS

Fifty studies were included in the final analysis. SUVmax is significantly higher in ER-negative (31 studies, SMD 0.66, 0.56-0.77, P < 0.0001), PR-negative (30 studies, SMD 0.56; 0.40-0.71, P < 0.0001), HER2-positive (32 studies, SMD - 0.29, - 0.49 to - 0.10, P = 0.0043) or Ki-67-positive (19 studies, SMD - 0.77; - 0.93 to - 0.61, P < 0.0001) primary tumours compared to their counterparts. The majority of clinical subtypes were either luminal A (LA), luminal B (LB), HER2-positive or triple negative breast cancer (TNBC). LA is associated with significantly lower SUVmax compared to LB (11 studies, SMD - 0.49, - 0.68 to - 0.31, P = 0.0001), HER2-positive (15 studies, SMD - 0.91, - 1.21 to - 0.61, P < 0.0001) and TNBC (17 studies, SMD - 1.21, - 1.57 to - 0.85, P < 0.0001); and LB showed significantly lower uptake compared to TNBC (10 studies, SMD - 0.77, - 1.05 to - 0.49, P = 0.0002). Differences in SUVmax between LB and HER2-positive (9 studies, SMD - 0.32, - 0.88 to 0.24, P = 0.2244), and HER2-positive and TNBC (17 studies, SMD - 0.29, - 0.61 to 0.02, P = 0.0667) are not significant.

CONCLUSION

Primary tumour SUVmax is significantly higher in ER-negative, PR-negative, HER2-positive and Ki-67-positive breast cancer patients. Luminal tumours have the lowest and TNBC tumours the highest SUVmax. HER2 overexpression has an intermediate effect.

Comparing the Diagnostic Performance of Contrast-Enhanced Mammography and Breast MRI: a Systematic Review and Meta-Analysis

Background: To provide a systematic review and meta-analysis that evaluates the diagnostic accuracy of contrast-enhanced mammography (CEM) compared to standard contrast-enhanced breast magnetic resonance imaging (breast MRI). Like breast MRI, CEM enables tumour visualization by contrast accumulation. CEM seems to be a viable substitute for breast MRI. Methods: This systematic search assessed the diagnostic accuracy of these techniques in women with suspicious breast lesions on prior imaging or physical examination, who have undergone both breast MRI and CEM. CEM had to be performed on a commercially available system. The MRI sequence parameters had to be described sufficiently to ensure that standard breast MRI sequence protocols were used. Pooled values of sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio (DOR), were estimated using bivariate mixed-effects logistic regression modeling. Hierarchical summary receiver operating characteristic curves for CEM and breast MRI were also constructed. Results: Six studies (607 patients with 775 lesions) met the predefined inclusion criteria. Pooled sensitivity was 96% for CEM and 97% for breast MRI. Pooled specificity was 77% for both modalities. DOR was 79.5 for CEM and 122.9 for breast MRI. Between-study heterogeneity expressed as the I2 -index was substantial with values over 80%. Conclusion: Pooled sensitivity was high for both CEM and breast MRI, with moderate specificity. The pooled DOR estimates, however, indicate higher overall diagnostic performance of breast MRI compared to CEM. Nonetheless, current scientific evidence is too limited to prematurely discard CEM as an alternative for breast MRI.

Diagnostic Accuracy of Radioactive Iodine Seed Placement in the Axilla With Sentinel Lymph Node Biopsy After Neoadjuvant Chemotherapy in Node-Positive Breast Cancer

Importance

Several less-invasive staging procedures have been proposed to replace axillary lymph node dissection (ALND) after neoadjuvant chemotherapy (NAC) in patients with initially clinically node-positive (cN+) breast cancer, but these procedures may fail to detect residual disease. Owing to the lack of high-level evidence, it is not yet clear which procedure is most optimal to replace ALND.

Objective

To determine the diagnostic accuracy of radioactive iodine seed placement in the axilla with sentinel lymph node biopsy (RISAS), a targeted axillary dissection procedure.

Design, Setting, and Participants

This was a prospective, multicenter, noninferiority, diagnostic accuracy trial conducted from March 1, 2017, to December 31, 2019. Patients were included within 14 institutions (general, teaching, and academic) throughout the Netherlands. Patients with breast cancer clinical tumor categories 1 through 4 (cT1-4; tumor diameter <2 cm and up to >5 cm or extension to the chest wall or skin) and pathologically proven positive axillary lymph nodes (ie, clinical node categories cN1, metastases to movable ipsilateral level I and/or level II axillary nodes; cN2, metastases to fixed or matted ipsilateral level I and/or level II axillary nodes; cN3b, metastases to ipsilateral level I and/or level II axillary nodes with metastases to internal mammary nodes) who were treated with NAC were eligible for inclusion. Data were analyzed from July 2020 to December 2021.

Intervention

Pre-NAC, the marking of a pathologically confirmed positive axillary lymph node with radioactive iodine seed (MARI) procedure, was performed and after NAC, sentinel lymph node biopsy (SLNB) combined with excision of the marked lymph node (ie, RISAS procedure) was performed, followed by ALND.

Main Outcomes and Measures

The identification rate, false-negative rate (FNR), and negative predictive value (NPV) were calculated for all 3 procedures: RISAS, SLNB, and MARI. The noninferiority margin of the observed FNR was 6.25% for the RISAS procedure.

Results

A total of 212 patients (median [range] age, 52 [22-77] years) who had cN+ breast cancer underwent the RISAS procedure and ALND. The identification rate of the RISAS procedure was 98.2% (223 of 227). The identification rates of SLNB and MARI were 86.4% (197 of 228) and 94.1% (224 of 238), respectively. FNR of the RISAS procedure was 3.5% (5 of 144; 90% CI, 1.38-7.16), and NPV was 92.8% (64 of 69; 90% CI, 85.37-97.10), compared with an FNR of 17.9% (22 of 123; 90% CI, 12.4%-24.5%) and NPV of 72.8% (59 of 81; 90% CI, 63.5%-80.8%) for SLNB and an FNR of 7.0% (10 of 143; 90% CI, 3.8%-11.6%) and NPV of 86.3% (63 of 73; 90% CI, 77.9%-92.4%) for the MARI procedure. In a subgroup of 174 patients in whom SLNB and the MARI procedure were successful and ALND was performed, FNR of the RISAS procedure was 2.5% (3 of 118; 90% CI, 0.7%-6.4%), compared with 18.6% (22 of 118; 90% CI, 13.0%-25.5%) for SLNB (P < .001) and 6.8% (8 of 118; 90% CI, 3.4%-11.9%) for the MARI procedure (P = .03).

Conclusions and Relevance

Results of this diagnostic study suggest that the RISAS procedure was the most feasible and accurate less-invasive procedure for axillary staging after NAC in patients with cN+ breast cancer.

Axillary lymph node response to neoadjuvant systemic therapy with dedicated axillary hybrid 18F-FDG PET/MRI in clinically node-positive breast cancer patients: a pilot study

AIM

To investigate the diagnostic performance of dedicated axillary hybrid ¹⁸F-2-[¹⁸F]-fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET)/magnetic resonance imaging (MRI) in detecting axillary pathological complete response (pCR) following neoadjuvant systemic therapy (NST) in clinically node-positive breast cancer patients.

MATERIALS AND METHODS

Ten prospectively included clinically node-positive breast cancer patients underwent dedicated axillary hybrid ¹⁸F-FDG PET/MRI after completing NST followed by axillary surgery. PET images were reviewed by a nuclear medicine physician and coronal T1-weighted and T2-weighted MRI images by a radiologist. All axillary lymph nodes visible on PET/MRI were matched with those removed during axillary surgery. Diagnostic performance parameters were calculated based on patient-by-patient and node-by-node validation with histopathology of the axillary surgical specimen as the reference standard.

RESULTS

Six patients achieved axillary pCR at final histopathology. A total of 84 surgically harvested axillary lymph nodes were matched with axillary lymph nodes depicted on PET/MRI. Histopathological examination of the matched axillary lymph nodes resulted in 10 lymph nodes with residual axillary disease of which eight contained macrometastases and two micrometastases. The patient-by-patient analysis yielded a sensitivity, specificity, positive predictive value, and negative predictive value of 25%, 100%, 100%, and 67%, respectively. The diagnostic performance parameters of the node-by-node analysis were 0%, 96%, 0%, and 88%, respectively. Excluding micrometastases from the node-by-node analysis increased the negative predictive value to 90%.

CONCLUSION

This pilot study suggests that the negative predictive value and sensitivity of dedicated axillary ¹⁸F-FDG PET/MRI are insufficiently accurate to detect axillary pCR or exclude residual axillary disease following NST in clinically node-positive breast cancer patients.

A descriptive systematic review of the relationship between personality traits and quality of life of women with non-metastatic breast cancer

BACKGROUND

Quality of life (QoL) is an important patient-reported outcome that has been studied extensively as an endpoint. There is a growing interest in factors that may influence QoL, such as personality. This descriptive systematic review examined the relationship between personality and QoL in women with non-metastatic breast cancer.  METHODS: On November 24th, 2020, with a update on March 7th, 2022, PubMed, PsycINFO, CINAHL, Web of Science and Embase were systematically searched for studies that assessed the direct relationship between personality traits and QoL among adult women diagnosed with non-metastatic breast cancer. The National Institutes of Health Study Quality Assessment Tool was used to assess the quality and risk of bias of the included studies. Three reviewers independently extracted data regarding objectives, population, setting, design, method, outcome measurements and key results. The results are descriptively reported.

RESULTS

Twelve studies (6 cohort studies and 6 cross-sectional studies) were included. Three studies were rated as poor, one study was rated as good, and the remaining studies were rated as moderate. There was a small to moderate effect of personality on QoL as correlation coefficients ranged from 0.10 to 0.77, and the explained variance ranged from 4 to 43%. The (strength of the) relationship depended on the personality trait and QoL domain that was measured and was most apparent for the personality traits 'optimism' and 'trait anxiety' on psychosocial QoL domains. The results for the personality traits (unmitigated) agency, agreeableness, conscientiousness, novelty seeking, and self-efficacy indicated a smaller but statistically significant correlation between these personality traits and QoL.

CONCLUSIONS

The results confirm that personality affects QoL in women with non-metastatic breast cancer and thus provides evidence that personality traits are indeed important influential factors of QoL. It is therefore strongly recommended for all future QoL research to measure personality traits and use these variables as predictive factors, as they are needed to accurately interpret QoL. Information regarding personality traits provide physicians and patients with an interpretation of low or deterioration of QoL, which could guide physicians to improve their patients' health outcomes and subsequently QoL using psycho-oncological support or treatment.

De-Escalating Axillary Surgery in Node-Positive Breast Cancer Treated with Neoadjuvant Systemic Therapy

Background

There is a trend towards de-escalating axillary staging and treatment in breast cancer patients. On account of neoadjuvant systemic therapy, node-positive breast cancer patients can achieve a pathological complete response of the axilla. It is hypothesized that these patients do not benefit from an axillary lymph node dissection (ALND), and thus may be spared the risk of severe post-surgical morbidity. In an effort to omit standard ALND, less invasive axillary staging procedures are being implemented to establish response-guided treatment. However, it is unclear which less invasive staging procedure is most accurate, and long-term data are missing with regard to their oncologic safety.

Summary

This article provides an overview of the literature on currently used less invasive axillary staging procedures, the accuracy and feasibility of these procedures in clinical practice, important issues concerning axillary treatment, and issues to be addressed in ongoing or future studies.

Key messages

More evidence is needed regarding the safety of replacing standard ALND by less invasive axillary staging procedures in terms of long-term prognosis. These less invasive staging procedures not only serve to select patients who may benefit from treatment de-escalation, but also to select patients who may benefit from treatment escalation.

The initial hormone receptor/HER2 subtype is the main determinator of subtype discordance in advanced breast cancer: a study of the SONABRE registry

Purpose

The hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) are the main parameters in guiding systemic treatment choices in breast cancer, but can change during the disease course. This study aims to evaluate the biopsy rate and receptor subtype discordance rate in patients diagnosed with advanced breast cancer (ABC).

Methods

Patients diagnosed with ABC in seven hospitals in 2007–2018 were selected from the SOutheast Netherlands Advanced BREast cancer (SONABRE) registry. Multivariable logistic regression analyses were performed to identify factors influencing biopsy and discordance rates.

Results

Overall, 60% of 2854 patients had a biopsy of a metastatic site at diagnosis. One of the factors associated with a reduced biopsy rate was the HR + /HER2 + primary tumor subtype (versus HR + /HER2- subtype: OR = 0.68; 95% CI: 0.51–0.90). Among the 748 patients with a biopsy of the primary tumor and a metastatic site, the overall receptor discordance rate was 18%. This was the highest for the HR + /HER2 + primary tumor subtype, with 55%. In 624 patients with metachronous metastases, the HR + /HER2 + subtype remained the only predictor significantly related to a higher discordance rate, irrespective of prior (neo-)adjuvant therapies (OR = 7.49; 95% CI: 3.69–15.20).

Conclusion

The HR + /HER2 + subtype has the highest discordance rate, but the lowest biopsy rate of all four receptor subtypes. Prior systemic therapy was not independently related to subtype discordance. This study highlights the importance of obtaining a biopsy of metastatic disease, especially in the HR + /HER2 + subtype to determine the most optimal treatment strategy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10549-021-06472-5.

Test-Retest Data for the Assessment of Breast MRI Radiomic Feature Repeatability

Background

Radiomic features extracted from breast MRI have potential for diagnostic, prognostic, and predictive purposes. However, before they can be used as biomarkers in clinical decision support systems, features need to be repeatable and reproducible.

Objective

Identify repeatable radiomics features within breast tissue on prospectively collected MRI exams through multiple test–retest measurements.

Study Type

Prospective.

Population

11 healthy female volunteers.

Field Strength/Sequence

1.5 T; MRI exams, comprising T2‐weighted turbo spin‐echo (T2W) sequence, native T1‐weighted turbo gradient‐echo (T1W) sequence, diffusion‐weighted imaging (DWI) sequence using b‐values 0/150/800, and corresponding derived ADC maps.

Assessment

18 MRI exams (three test–retest settings, repeated on 2 days) per healthy volunteer were examined on an identical scanner using a fixed clinical breast protocol. For each scan, 91 features were extracted from the 3D manually segmented right breast using Pyradiomics, before and after image preprocessing. Image preprocessing consisted of 1) bias field correction (BFC); 2) z‐score normalization with and without BFC; 3) grayscale discretization using 32 and 64 bins with and without BFC; and 4) z‐score normalization + grayscale discretization using 32 and 64 bins with and without BFC.

Statistical Tests

Features' repeatability was assessed using concordance correlation coefficient(CCC) for each pair, i.e. each MRI was compared to each of the remaining 17 MRI with a cut‐off value of CCC > 0.90.

Results

Images without preprocessing produced the highest number of repeatable features for both T1W sequence and ADC maps with 15 of 91 (16.5%) and 8 of 91 (8.8%) repeatable features, respectively. Preprocessed images produced between 4 of 91 (4.4%) and 14 of 91 (15.4%), and 6 of 91 (6.6%) and 7 of 91 (7.7%) repeatable features, respectively for T1W and ADC maps. Z‐score normalization produced highest number of repeatable features, 26 of 91 (28.6%) in T2W sequences, in these images, no preprocessing produced 11 of 91 (12.1%) repeatable features.

Data Conclusion

Radiomic features extracted from T1W, T2W sequences and ADC maps from breast MRI exams showed a varying number of repeatable features, depending on the sequence. Effects of different preprocessing procedures on repeatability of features were different for each sequence.

Level of Evidence

2

Technical Efficacy Stage

1

Intestinal Microbiota in Postmenopausal Breast Cancer Patients and Controls

Simple Summary

Besides the already known factors that increase the risk of breast cancer, like hormonal treatment, heredity, and obesity, growing evidence exists that intestinal microbiota can influence breast cancer carcinogenesis. Current clinical information into the role of the intestinal microbiota in breast cancer patients is limited. This study aimed to see whether there are differences in intestinal microbiota richness, diversity, and composition between oestrogen receptor positive breast cancer patients and controls. We concluded that the intestinal microbiota richness, diversity, and composition were not different between breast cancer patients and postmenopausal controls. An increased relative abundance of Dialister and Veillonellaceae was observed in breast cancer patients scheduled for adjuvant treatment, which might be caused by a relative decrease in other bacteria due to surgery associated factors rather than an absolute increase. For future studies, we strongly advise a more homogeneous group of breast cancer patients of preferably treatment-naive patients.

Abstract

Background: Previous preclinical and clinical research has investigated the role of intestinal microbiota in carcinogenesis. Growing evidence exists that intestinal microbiota can influence breast cancer carcinogenesis. However, the role of intestinal microbiota in breast cancer needs to be further investigated. This study aimed to identify the microbiota differences between postmenopausal breast cancer patients and controls. Patients and methods: This prospective cohort study compared the intestinal microbiota richness, diversity, and composition in postmenopausal histologically proven ER+/HER2- breast cancer patients and postmenopausal controls. Patients scheduled for (neo)adjuvant adriamycin, cyclophosphamide (AC), and docetaxel (D), or endocrine therapy (tamoxifen) were prospectively enrolled in a multicentre cohort study in the Netherlands. Patients collected a faecal sample and completed a questionnaire before starting systemic cancer treatment. Controls, enrolled from the National Dutch Breast Cancer Screening Programme, also collected a faecal sample and completed a questionnaire. Intestinal microbiota was analysed by amplicon sequencing of the 16S rRNA V4 gene region. Results: In total, 81 postmenopausal ER+/HER2- breast cancer patients and 67 postmenopausal controls were included, resulting in 148 faecal samples. Observed species richness, Shannon index, and overall microbial community structure were not significantly different between breast cancer patients and controls. There was a significant difference in overall microbial community structure between breast cancer patients scheduled for adjuvant treatment, neoadjuvant treatment, and controls at the phylum (p = 0.042) and genus levels (p = 0.015). Dialister (p = 0.001) and its corresponding family Veillonellaceae (p = 0.001) were higher in patients scheduled for adjuvant treatment, compared to patients scheduled for neoadjuvant treatment. Additional sensitivity analysis to correct for the potential confounding effect of prophylactic antibiotic use, indicated no differences in microbial community structure between patients scheduled for neoadjuvant systemic treatment, adjuvant systemic treatment, and controls at the phylum (p = 0.471) and genus levels (p = 0.124). Conclusions: Intestinal microbiota richness, diversity, and composition are not different between postmenopausal breast cancer patients and controls. The increased relative abundance of Dialister and Veillonellaceae was observed in breast cancer patients scheduled for adjuvant treatment, which might be caused by a relative decrease in other bacteria due to prophylactic antibiotic administration rather than an absolute increase.

Gut microbiota and short-chain fatty acid alterations in cachectic cancer patients

BACKGROUND

Cancer cachexia is characterized by a negative energy balance, muscle and adipose tissue wasting, insulin resistance, and systemic inflammation. Because of its strong negative impact on prognosis and its multifactorial nature that is still not fully understood, cachexia remains an important challenge in the field of cancer treatment. Recent animal studies indicate that the gut microbiota is involved in the pathogenesis and manifestation of cancer cachexia, but human data are lacking. The present study investigates gut microbiota composition, short-chain fatty acids (SCFA), and inflammatory parameters in human cancer cachexia.

METHODS

Faecal samples were prospectively collected in patients (N = 107) with pancreatic cancer, lung cancer, breast cancer, or ovarian cancer. Household partners (N = 76) of the patients were included as healthy controls with similar diet and environmental conditions. Patients were classified as cachectic if they lost >5% body weight in the last 6 months. Gut microbiota composition was analysed by sequencing of the 16S rRNA V4 gene region. Faecal SCFA levels were quantified by gas chromatography. Faecal calprotectin was assessed with enzyme-linked immunosorbent assay. Serum C-reactive protein and leucocyte counts were retrieved from medical records.

RESULTS

Cachexia prevalence was highest in pancreatic cancer (66.7%), followed by ovarian cancer (25%), lung cancer (20.8%), and breast cancer (17.3%). Microbial α-diversity was not significantly different between cachectic cancer patients (N = 33), non-cachectic cancer patients (N = 74), or healthy controls (N = 76) (species richness P = 0.31; Shannon effective index P = 0.46). Community structure (β-diversity) tended to differ between these groups (P = 0.053), although overall differences were subtle and no clear clustering of samples was observed. Proteobacteria (P < 0.001), an unknown genus from the Enterobacteriaceae family (P < 0.01), and Veillonella (P < 0.001) were more abundant among cachectic cancer patients. Megamonas (P < 0.05) and Peptococcus (P < 0.001) also showed differential abundance. Faecal levels of all SCFA tended to be lower in cachectic cancer patients, but only acetate concentrations were significantly reduced (P < 0.05). Faecal calprotectin levels were positively correlated with the abundance of Peptococcus, unknown Enterobacteriaceae, and Veillonella. We also identified several correlations and interactions between clinical and microbial parameters.

CONCLUSIONS

This clinical study provided the first insights into the alterations of gut microbiota composition and SCFA levels that occur in cachectic cancer patients and how they are related to inflammatory parameters. These results pave the way for further research examining the role of the gut microbiota in cancer cachexia and its potential use as therapeutic target.

Value of 18F-FDG PET/CT for predicting axillary pathologic complete response following neoadjuvant systemic therapy in breast cancer patients: emphasis on breast cancer subtype

Background

Neoadjuvant systemic therapy (NST) is a widely accepted initial treatment modality that can lead to pathologic downstaging of the axillary disease burden in breast cancer patients. Axillary response as well as baseline ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) uptake on positron emission tomography with computed tomography (PET/CT) differ between breast cancer subtypes. The value of baseline ¹⁸F-FDG PET/CT in predicting axillary response to NST is not yet established, possibly since breast cancer subtype was not taken into account. The purpose of this study was to investigate the value of baseline ¹⁸F-FDG PET/CT in predicting axillary response to NST with a specific emphasis on subtype.

Methods

PET-parameters derived from the primary tumor as well as the most FDG-avid axillary lymph node were measured on baseline ¹⁸F-FDG PET/CT. Overall imaging findings were compared with the gold standard of histopathology of the axillary surgery specimen. Analyses for ER-positive/HER2-negative were performed separately from HER2-positive and TN patients. In addition, separate analyses for clinically node-positive patients were performed.

Results

Sixty-six patients with 69 primary tumors were included in this study. Thirty-three axillae contained ER-positive/HER2-negative, 16 HER2-positive, and 20 TN breast cancer. No significant difference in PET-parameters between patients with axillary residual disease and axillary pathologic complete response were found for ER-positive/HER2-negative breast cancer. In the combined HER2-positive/TN subgroup, the SUV_max was significantly lower in patients without residual axillary disease in both the entire cohort and in patients with clinically node-positive disease. In this combined subgroup, a cut-off of 4.89 SUV_max measured on the most FDG-avid axillary lymph node could predict residual axillary disease with a sensitivity, specificity, PPV, and NPV of 90%, 69%, 53%, and 95%, respectively.

Conclusions

Predicting axillary response following NST with baseline ¹⁸F-FDG PET/CT can be performed when focusing on breast cancer subtypes. The easily computed PET-parameter SUV_max can predict axillary response in HER2-positive and TN breast cancer. This study adds to the accumulating evidence that studies investigating the value of ¹⁸F-FDG PET/CT in breast cancer should always take subtypes into account.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13550-021-00861-z.

The percentage of residual DCIS in patients diagnosed with primary invasive breast cancer treated with neoadjuvant systemic therapy: A nationwide retrospective study

INTRODUCTION

Neoadjuvant systemic therapy (NST) is increasingly applied in breast cancer to improve surgical and oncological outcome. Approximately 21% of patients receiving NST achieve pathological complete response (pCR) of the breast. There is disagreement on the definition of pCR with respect to residual DCIS (ypT0 versus ypT0/is). The aim of this retrospective study was to determine the percentage of breast pCR (ypT0) and residual DCIS (ypTis), and its association with clinicopathological variables, in patients treated with NST and surgery.

MATERIALS AND METHODS

Patients with invasive breast cancer treated with neoadjuvant chemotherapy, with or without targeted therapy, in the period of 2010-2019 were selected from the Netherlands Cancer Registry (NCR). Descriptive statistics and multivariable logistic regression analyses were used to analyse the percentage of ypT0 and ypTis and its association with clinicopathological variables.

RESULTS

From the NCR database, 20495 patients were included, of whom 5847 (28.5%) achieved breast pCR (ypT0) and 881 (4.3%) showed residual DCIS (ypTis). The percentage of ypTis was highest in HER2+ tumour subtypes (ER+HER2+ 7.9%, ER-HER2+ 9.8%, ER+HER2- 2.1%, triple negative 3.3%, p < 0.001). Multivariable logistic regression analyses demonstrated high tumour grade (OR 2.00, p = 0.003) and HER2+ tumour subtype (ER+HER2+ OR 3.58, ER-HER2+ OR 4.37, p < 0.001) as independent predictors for ypTis.

CONCLUSION

pCR (ypT0) was achieved in 5847 (28.5%) patients receiving NST and residual DCIS (ypTis) was found in 881 (4.3%) patients. Consequently, the rate of pCR may be affected by ypTis when not excluded from the definition. The percentage of ypTis is highest in HER2+ subtypes.

The Role of Intestinal Microbiota in Metastatic Colorectal Cancer Patients Treated With Capecitabine

BACKGROUND

Previous pre-clinical research has indicated that the intestinal microbiota can potentiate anti-tumour efficacy of capecitabine and that capecitabine treatment impacts intestinal microbiota composition and diversity. Using a longitudinal design, this study explores the associations between the intestinal microbiota and treatment response in patients with metastatic colorectal cancer (mCRC) during capecitabine treatment.

PATIENTS AND METHODS

Patients with mCRC treated with capecitabine were prospectively enrolled in a multicentre cohort study. Patients collected a faecal sample and completed a questionnaire before, during, and after three cycles of capecitabine. Several clinical characteristics, including tumour response, toxicity and antibiotic use were recorded. Intestinal microbiota were analysed by amplicon sequencing of the 16S rRNA V4 gene-region.

RESULTS

Thirty-three patients were included. After three cycles of capecitabine, six patients (18%) achieved a partial response, 25 (76%) showed stable disease, and one (3%) experienced progressive disease. Of the 90 faecal samples were collected. Microbial diversity (α-diversity), community structure (β-diversity), and bacterial abundance on phylum and genus level were not significantly different between responders and non-responders and were not significantly affected by three cycles of capecitabine.

CONCLUSION

This is the first clinical study with longitudinal intestinal microbiota sampling in mCRC patients that explores the role of the intestinal microbiota during treatment with capecitabine. Intestinal microbiota composition and diversity before, during, and after three cycles of capecitabine were not associated with response in this study population. Capecitabine did not induce significant changes in the microbiota composition and diversity during the treatment period. Individual effects of antibiotics during capecitabine treatment were observed.

Contrast-enhanced mammography: what the radiologist needs to know

Contrast-enhanced mammography (CEM) is a combination of standard mammography and iodinated contrast material administration. During the last decade, CEM has found its place in breast imaging protocols: after i.v. administration of iodinated contrast material, low-energy and high-energy images are retrieved in one acquisition using a dual-energy technique, and a recombined image is constructed enabling visualisation of areas of contrast uptake. The increased incorporation of CEM into everyday clinical practice is reflected in the installation of dedicated equipment worldwide, the (commercial) availability of systems from different vendors, the number of CEM examinations performed, and the number of scientific articles published on the subject. It follows that ever more radiologists will be confronted with this technique, and thus be required to keep up to date with the latest developments in the field. Most importantly, radiologists must have sufficient knowledge on how to interpret CEM images and be acquainted with common artefacts and pitfalls. This comprehensive review provides a practical overview of CEM technique, including CEM-guided biopsy; reading, interpretation and structured reporting of CEM images, including the accompanying learning curve, CEM artefacts and interpretation pitfalls; indications for CEM; disadvantages of CEM; and future developments.

MINImal vs. MAXimal Invasive Axillary Staging and Treatment After Neoadjuvant Systemic Therapy in Node Positive Breast Cancer: Protocol of a Dutch Multicenter Registry Study (MINIMAX)

BACKGROUND

Node positive breast cancer (cN+) patients with an axillary pathologic complete response after neoadjuvant systemic therapy (NST) are not expected to benefit from axillary lymph node dissection (ALND). Therefore, less invasive axillary staging procedures have been introduced to establish response-guided treatment. However, evidence is lacking with regard to their oncologic safety and impact on quality of life (QoL). We hypothesize that if response-guided treatment is given, less invasive staging procedures are non-inferior to standard ALND in terms of oncologic safety, and superior to standard ALND in terms of QoL.

PATIENTS AND METHODS

MINIMAX is a Dutch multicenter registry study that includes patients with cN1-3M0 unilateral invasive breast cancer, who receive NST, followed by axillary staging and treatment according to local protocols. In a retrospective registry of ±4000 patients, the primary endpoint is oncologic safety at 5 and 10 years (disease-free, breast-cancer-specific and overall survival, and axillary recurrence rate). In a prospective multicenter registry, the primary endpoints are QoL at 1 and 5 years, and we aim to verify the 5-year oncologic safety. With an estimated 5-year disease-free survival of 72.5% and anticipated loss to follow-up of 10%, a sample size of 549 is needed to have 80% power to detect non-inferiority (with a 10% margin) of less invasive staging procedures.

CONCLUSION

In cN+ patients treated with NST, less invasive axillary staging procedures are already implemented globally. Evidence is needed to support the assumed oncologic safety and superior QoL of such procedures. This study will contribute to evidence-based guidelines.

Axillary Pathologic Complete Response After Neoadjuvant Systemic Therapy by Breast Cancer Subtype in Patients With Initially Clinically Node-Positive Disease: A Systematic Review and Meta-analysis

Importance

An overview of rates of axillary pathologic complete response (pCR) for all breast cancer subtypes, both for patients with and without pathologically proven clinically node-positive disease, is lacking.

Objective

To provide pooled data of all studies in the neoadjuvant setting on axillary pCR rates for different breast cancer subtypes in patients with initially clinically node-positive disease.

Data Sources

The electronic databases Embase and PubMed were used to conduct a systematic literature search on July 16, 2020. The references of the included studies were manually checked to identify other eligible studies.

Study Selection

Studies in the neoadjuvant therapy setting were identified regarding axillary pCR for different breast cancer subtypes in patients with initially clinically node-positive disease (ie, defined as node-positive before the initiation of neoadjuvant systemic therapy).

Data Extraction and Synthesis

Two reviewers independently selected eligible studies according to the inclusion criteria and extracted all data. All discrepant results were resolved during a consensus meeting. To identify the different subtypes, the subtype definitions as reported by the included articles were used. The random-effects model was used to calculate the overall pooled estimate of axillary pCR for each breast cancer subtype.

Main Outcomes and Measures

The main outcome of this study was the rate of axillary pCR and residual axillary lymph node disease after neoadjuvant systemic therapy for different breast cancer subtypes, differentiating studies with and without patients with pathologically proven clinically node-positive disease.

Results

This pooled analysis included 33 unique studies with 57 531 unique patients and showed the following axillary pCR rates for each of the 7 reported subtypes in decreasing order: 60% for hormone receptor (HR)-negative/ERBB2 (formerly HER2)-positive, 59% for ERBB2-positive (HR-negative or HR-positive), 48% for triple-negative, 45% for HR-positive/ERBB2-positive, 35% for luminal B, 18% for HR-positive/ERBB2-negative, and 13% for luminal A breast cancer. No major differences were found in the axillary pCR rates per subtype by analyzing separately the studies of patients with and without pathologically proven clinically node-positive disease before neoadjuvant systemic therapy.

Conclusions and Relevance

The HR-negative/ERBB2-positive subtype was associated with the highest axillary pCR rate. These data may help estimate axillary treatment response in the neoadjuvant setting and thus select patients for more or less invasive axillary procedures.

MRI-Based Radiomics Analysis for the Pretreatment Prediction of Pathologic Complete Tumor Response to Neoadjuvant Systemic Therapy in Breast Cancer Patients: A Multicenter Study

This retrospective study investigated the value of pretreatment contrast-enhanced Magnetic Resonance Imaging (MRI)-based radiomics for the prediction of pathologic complete tumor response to neoadjuvant systemic therapy in breast cancer patients. A total of 292 breast cancer patients, with 320 tumors, who were treated with neo-adjuvant systemic therapy and underwent a pretreatment MRI exam were enrolled. As the data were collected in two different hospitals with five different MRI scanners and varying acquisition protocols, three different strategies to split training and validation datasets were used. Radiomics, clinical, and combined models were developed using random forest classifiers in each strategy. The analysis of radiomics features had no added value in predicting pathologic complete tumor response to neoadjuvant systemic therapy in breast cancer patients compared with the clinical models, nor did the combined models perform significantly better than the clinical models. Further, the radiomics features selected for the models and their performance differed with and within the different strategies. Due to previous and current work, we tentatively attribute the lack of improvement in clinical models following the addition of radiomics to the effects of variations in acquisition and reconstruction parameters. The lack of reproducibility data (i.e., test-retest or similar) meant that this effect could not be analyzed. These results indicate the need for reproducibility studies to preselect reproducible features in order to properly assess the potential of radiomics.

Rate and predictors of nodal pathological complete response following neoadjuvant endocrine treatment in clinically biopsy-proven node-positive breast cancer patients

BACKGROUND

Data on effectiveness and optimal use of neoadjuvant endocrine therapy (NET) in clinically biopsy-proven node-positive breast cancer is lacking. This study examined the incidence of axillary pathological complete response (pCR) on NET in clinically biopsy-proven node-positive breast cancer patients. Secondary, patient and tumour characteristics, as well as the optimal duration of NET in relation to the occurrence of axillary pCR were investigated.

MATERIAL AND METHODS

Patients diagnosed with primary hormone receptor positive, HER2 negative breast cancer between 2014 and 2019, with at least one positive axillary lymph node (pathologically proven), treated with NET were selected from the Netherlands Cancer Registry. The incidence of axillary pCR in combination with patient, tumour and treatment characteristics was analysed.

RESULTS

In a population of 561 patients, an axillary pCR of 7.3% on NET was observed. Median length of treatment was 8.1 months in the patients without vs. 8.8 months in those with axillary pCR, with no statistically significant difference. A p-value <0.30 was found for age, histologic type, clinical tumour status, hormone receptor status and the type of NET in univariable analysis. After multivariable logistic regression analyses, none of these variables were independently associated with the likelihood of an axillary pCR.

CONCLUSION

The rate of axillary pCR after NET in HR + HER2-clinically biopsy-proven node-positive breast cancer patients is low. Factors independently associated with the likelihood of an axillary pCR could not be identified. More research is warranted regarding optimizing the duration of NET and the prognostic value of residual disease in the axilla after NET.

Gut microbiota and metabolic aspects of cancer cachexia

Cancer cachexia is a metabolic syndrome characterized by unintended weight loss and muscle wasting. It has a strong negative impact on survival. Its underlying mechanisms involve systemic inflammation and insulin resistance, which are known to be influenced by the gut microbiota. Preclinical studies support a role for the gut microbiota in cancer cachexia by demonstrating that cachectic mice display: 1) various gut microbiota composition changes; 2) increased gut permeability and translocation of pro-inflammatory microbial compounds; 3) muscle atrophy-related processes linked to gut microbiota properties; 4) positive effects of microbiota-modulating interventions. Data on the relationships between gut microbiota, insulin resistance, and hepatic/adipose tissue metabolism in cachexia models are lacking. Nevertheless, the available data and existing evidence for the impact of gut microbiota on metabolic aberrations in human obesity urge for exploration of its role in human cancer cachexia. We provide practical recommendations and discuss the challenges for such future clinical studies.

Impact of the COVID-19 pandemic on diagnosis, stage, and initial treatment of breast cancer in the Netherlands: a population-based study

BACKGROUND

The onset of the COVID-19 pandemic forced the Dutch national screening program to a halt and increased the burden on health care services, necessitating the introduction of specific breast cancer treatment recommendations from week 12 of 2020. We aimed to investigate the impact of COVID-19 on the diagnosis, stage and initial treatment of breast cancer.

METHODS

Women included in the Netherlands Cancer Registry and diagnosed during four periods in weeks 2-17 of 2020 were compared with reference data from 2018/2019 (averaged). Weekly incidence was calculated by age group and tumor stage. The number of women receiving initial treatment within 3 months of diagnosis was calculated by period, initial treatment, age, and stage. Initial treatment, stratified by tumor behavior (ductal carcinoma in situ [DCIS] or invasive), was analyzed by logistic regression and adjusted for age, socioeconomic status, stage, subtype, and region. Factors influencing time to treatment were analyzed by Cox regression.

RESULTS

Incidence declined across all age groups and tumor stages (except stage IV) from 2018/2019 to 2020, particularly for DCIS and stage I disease (p < 0.05). DCIS was less likely to be treated within 3 months (odds ratio [OR]wks2-8: 2.04, ORwks9-11: 2.18). Invasive tumors were less likely to be treated initially by mastectomy with immediate reconstruction (ORwks12-13: 0.52) or by breast conserving surgery (ORwks14-17: 0.75). Chemotherapy was less likely for tumors diagnosed in the beginning of the study period (ORwks9-11: 0.59, ORwks12-13: 0.66), but more likely for those diagnosed at the end (ORwks14-17: 1.31). Primary hormonal treatment was more common (ORwks2-8: 1.23, ORwks9-11: 1.92, ORwks12-13: 3.01). Only women diagnosed in weeks 2-8 of 2020 experienced treatment delays.

CONCLUSION

The incidence of breast cancer fell in early 2020, and treatment approaches adapted rapidly. Clarification is needed on how this has affected stage migration and outcomes.

Repeat breast-conserving treatment of ipsilateral breast cancer recurrence: a nationwide survey amongst breast surgeons and radiation oncologists in the Netherlands

Background

In line with the paradigm to minimize surgical morbidity in patients with primary breast cancer, there is increasing evidence for the safety of a repeat breast-conserving treatment (BCT) of an ipsilateral breast tumour recurrence (IBTR) in selected patients. The conditions for the feasibility of a repeat BCT vary widely in literature. In clinical practice, many physicians have ongoing concerns about the oncological safety and possible toxicity of repeat BCT.

Aim

To investigate the attitude of Dutch breast surgeons and radiation oncologists towards repeat BCT and to report on their experiences with, objections against and perceived requirements to consider a repeat BCT in case of IBTR.

Patients and methods

An online survey consisting of a maximum of 26 open and multiple-choice questions about repeat BCT for IBTR was distributed amongst Dutch breast surgeons and radiation oncologists.

Results

Forty-nine surgeons representing 49% of Dutch hospitals and 20 radiation oncologists representing 70% of Dutch radiation oncology centres responded. A repeat BCT was considered feasible in selected cases by 28.7% of breast surgeons and 55% of radiation oncologists. The most important factors to consider a repeat BCT for both groups were the patient’s preference to preserve the breast and surgical feasibility of a second lumpectomy. Arguments against a repeat BCT were based on the perceived unacceptable toxicity and cosmesis of a second course of radiotherapy. The technique of preference for re-irradiation would be partial breast irradiation (PBI) according to all radiation oncologists. Differentiating between new primary tumours (NPT) and true recurrences (TR) was reported to be done by 57.1% of breast surgeons and 60% of radiation oncologists. The most important reason to differentiate between NPT and TR was to establish prognosis and to consider whether a repeat BCT would be feasible.

Conclusion

An increasing number of Dutch breast cancer specialists is considering a repeat BCT feasible in selected cases, at the patient’s preference and with partial breast re-irradiation.

Conditional local recurrence risk: the effect of event-free years in different subtypes of breast cancer

Background

After breast cancer treatment, follow-up consists of physical examination and mammography for at least 5 years, to detect local and regional recurrence. The risk of recurrence may decrease after event-free time. This study aims to determine the risk of local recurrence (LR) as a first event until 5 years after diagnosis, conditional on being event-free for 1, 2, 3 and 4 years.

Methods

From the Netherlands Cancer Registry, all M0 breast cancers diagnosed between 2005 and 2008 were included. LR risk was calculated with Kaplan–Meier analysis, overall and for different subtypes. Conditional LR (assuming x event-free years) was determined by selecting event-free patients at x years, and calculating their LR risk within 5 years after diagnosis.

Results

Five-year follow-up was available for 34,453 patients. Overall, five-year LR as a first event occurred in 3.0%. This risk varied for different subtypes and was highest for triple negative (6.8%) and lowest for ER+PR+Her2− (2.2%) tumors. After 1, 2, 3 and 4 event-free years, the average risk of LR before 5 years after diagnosis decreased from 3.0 to 2.4, 1.6, 1.0, and 0.6%. The risk decreased in all subtypes, the effect was most pronounced in subtypes with the highest baseline risk (ER−Her2+ and triple negative breast cancer). After three event-free years, LR risk in the next 2 years was 1% or less in all subtypes except triple negative (1.6%).

Conclusion

The risk of 5-year LR as a first event was low and decreased with the number of event-free years. After three event-free years, the overall risk was 1%. This is reassuring to patients and also suggests that follow-up beyond 3 years may produce low yield of LR, both for individual patients and studies using LR as primary outcome. This can be used as a starting point to tailor follow-up to individual needs.

Women Could Avoid Axillary Lymph Node Dissection by Choosing Breast-Conserving Therapy Instead of Mastectomy

BACKGROUND

The ACOSOG Z0011 trial showed that completion axillary lymph node dissection (cALND) can be safely omitted for some patients with T1-2 clinically node-negative breast cancer with one to two involved sentinel lymph nodes (SLNs) treated with breast-conserving therapy (BCT). There is little evidence for the safety of omitting cALND for mastectomy-treated patients. Consequently, cALND is often recommended for sentinel node-positive patients treated with mastectomy. The aim of this study is to determine the proportion of patients who could avoid cALND by choosing BCT instead of mastectomy at a tertiary cancer center.

PATIENTS AND METHODS

All T1-2 clinically node-negative breast cancer patients treated with BCT or mastectomy between 2012 and 2017 with metastases in the SLN(s) were selected from a prospectively maintained database. Clinical factors and outcomes were evaluated between the two groups. Differences were compared using Wilcoxon rank-sum test, chi-square test or Fisher's exact test as appropriate. Significance was set at the 0.05 level for all analyses.

RESULTS

A total of 306 patients were included, 199 (65.0%) of whom were treated with BCT and 107 (35.0%) with mastectomy. Patients treated with mastectomy were more often treated with cALND compared with those treated with BCT (71.0% versus 26.6%, p < 0.0001). Overall, 52 of the mastectomy patients (68.4%) could have avoided cALND if they had chosen BCT.

CONCLUSIONS

Patients treated with mastectomy are more likely to receive cALND than those treated with BCT. Axillary management should be addressed during discussion of primary tumor therapy, and cALND may be avoided when patients choose BCT instead of mastectomy.

Dedicated Axillary MRI-Based Radiomics Analysis for the Prediction of Axillary Lymph Node Metastasis in Breast Cancer

Radiomics features may contribute to increased diagnostic performance of MRI in the prediction of axillary lymph node metastasis. The objective of the study was to predict preoperative axillary lymph node metastasis in breast cancer using clinical models and radiomics models based on T2-weighted (T2W) dedicated axillary MRI features with node-by-node analysis. From August 2012 until October 2014, all women who had undergone dedicated axillary 3.0T T2W MRI, followed by axillary surgery, were retrospectively identified, and available clinical data were collected. All axillary lymph nodes were manually delineated on the T2W MR images, and quantitative radiomics features were extracted from the delineated regions. Data were partitioned patient-wise to train 100 models using different splits for the training and validation cohorts to account for multiple lymph nodes per patient and class imbalance. Features were selected in the training cohorts using recursive feature elimination with repeated 5-fold cross-validation, followed by the development of random forest models. The performance of the models was assessed using the area under the curve (AUC). A total of 75 women (median age, 61 years; interquartile range, 51-68 years) with 511 axillary lymph nodes were included. On final pathology, 36 (7%) of the lymph nodes had metastasis. A total of 105 original radiomics features were extracted from the T2W MR images. Each cohort split resulted in a different number of lymph nodes in the training cohorts and a different set of selected features. Performance of the 100 clinical and radiomics models showed a wide range of AUC values between 0.41-0.74 and 0.48-0.89 in the training cohorts, respectively, and between 0.30-0.98 and 0.37-0.99 in the validation cohorts, respectively. With these results, it was not possible to obtain a final prediction model. Clinical characteristics and dedicated axillary MRI-based radiomics with node-by-node analysis did not contribute to the prediction of axillary lymph node metastasis in breast cancer based on data where variations in acquisition and reconstruction parameters were not addressed.

Conditional regional recurrence risk: The effect of event-free years in different subtypes of breast cancer

BACKGROUND

Regional recurrence (RR), also known as lymph node recurrence, is an endpoint in several trials concerning reducing axillary treatment in cT1-2N0 breast cancer patients. The risk of RR may decrease with each subsequent event-free year, affecting the yield and consequently usefulness of long (er) follow-up. The aim of this study is to determine the risk of RR as a first event within five years after diagnosis in subtypes of breast cancer, conditional to being event-free for one, two, three and four years.

METHODS

From the Netherlands Cancer Registry, cT1-2N0 breast cancer patients diagnosed from 2005 to 2008 were analyzed. Subgroup analysis was performed for pT1-2N+(sn) patients. RR risk was calculated with Kaplan-Meier analysis. Conditional RR (assuming x event-free years) was determined by selecting patients without an event at x years, and calculating the remaining risk for RR within five years after diagnosis.

RESULTS

A total of 18,009 cT1-2N0 (all pN stages) breast cancer patients were included. RR occurred in 1.3% of cT1-2N0 and 1.5% of pT1-2N+(sn) patients. The risk of RR varied between subtypes; it was highest for triple negative tumors and lowest for ER + PR + Her2-and ER + Her2+ tumors. After event-free years, the risk of RR decreased subsequently in both groups and in all subtypes. After two event-free years, the risk of RR was 0.8%.

CONCLUSION

The absolute yield of follow-up to detect RR beyond two years is low; for every 125 event-free patients, one RR can be expected until five years. This suggests that follow-up longer than two years is of limited value for detecting RR in both clinical and research setting.

Stromal vapors for real-time molecular guidance of breast-conserving surgery

Achieving radical tumor resection while preserving disease-free tissue during breast-conserving surgery (BCS) remains a challenge. Here, mass spectrometry technologies were used to discriminate stromal tissues reported to be altered surrounding breast tumors, and build tissue classifiers ex vivo. Additionally, we employed the approach for in vivo and real-time classification of breast pathology based on electrosurgical vapors. Breast-resected samples were obtained from patients undergoing surgery at MUMC+. The specimens were subsequently sampled ex vivo to generate electrosurgical vapors analyzed by rapid evaporative ionization mass spectrometry (REIMS). Tissues were processed for histopathology to assign tissue components to the mass spectral profiles. We collected a total of 689 ex vivo REIMS profiles from 72 patients which were analyzed using multivariate statistical analysis (principal component analysis-linear discriminant analysis). These profiles were classified as adipose, stromal and tumor tissues with 92.3% accuracy with a leave-one patient-out cross-validation. Tissue recognition using this ex vivo-built REIMS classification model was subsequently tested in vivo on electrosurgical vapors. Stromal and adipose tissues were classified during one BCS. Complementary ex vivo analyses were performed by REIMS and by desorption electrospray ionization mass spectrometry (DESI-MS) to study the potential of breast stroma to guide BCS. Tumor border stroma (TBS) and remote tumor stroma (RTS) were classified by REIMS and DESI-MS with 86.4% and 87.8% accuracy, respectively. We demonstrate the potential of stromal molecular alterations surrounding breast tumors to guide BCS in real-time using REIMS analysis of electrosurgical vapors.

Diagnostic performance of PET/computed tomography versus PET/MRI and diffusion-weighted imaging in the N- and M-staging of breast cancer patients

OBJECTIVE

To provide a systematic review regarding the diagnostic performance of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/magnetic resonance imaging (PET/MRI) and diffusion-weighted imaging (DWI) compared to 18F-FDG PET/computed tomography (CT) focused on nodal and distant staging in breast cancer patients.

METHODS

The PubMed and Embase databases were searched for relevant publications until April 2020. Two independent reviewers searched for eligible articles based on predefined in- and exclusion criteria, assessed quality and extracted data.

RESULTS

Eleven eligible studies were selected from 561 publications identified by the search. In seven studies, PET/CT was compared with PET/MRI, and in five, PET/CT with DWI. Significantly higher sensitivity for PET/MRI compared to PET/CT in a lesion-based analysis was reported for all lesions together (77% versus 89%) in one study, osseous metastases (69-99% versus 92-98%) in two studies and hepatic metastases (70-75% versus 80-100%) in one study. Moreover, PET/MRI revealed a significantly higher amount of osseous metastases (90 versus 141) than PET/CT. PET/CT is associated with a statistically higher specificity than PET/MRI in the lesion detection of all lesions together (98% versus 96%) and of osseous metastases (100% versus 95%), both in one study. None of the reviewed studies reported significant differences between PET/CT and DWI for any of the evaluated sites. There is a trend toward higher specificity for PET/CT.

CONCLUSION

In general, there is a trend toward higher sensitivity and lower specificity of PET/MRI when compared to PET/CT. Results on the diagnostic performance of DWI are conflicting. Rather than evaluating it separate, it seems to have complementary value when combined with other MR sequences.

Evaluating the Age-Based Recommendations for Long-Term Follow-Up in Breast Cancer

Background

After 5 years of annual follow‐up following breast cancer, Dutch guidelines are age based: annual follow‐up for women <60 years, 60–75 years biennial, and none for >75 years. We determined how the risk of recurrence corresponds to these consensus‐based recommendations and to the risk of primary breast cancer in the general screening population.

Subjects, Materials, and Methods

Women with early‐stage breast cancer in 2003/2005 were selected from the Netherlands Cancer Registry (n = 18,568). Cumulative incidence functions were estimated for follow‐up years 5–10 for locoregional recurrences (LRRs) and second primary tumors (SPs). Risks were compared with the screening population without history of breast cancer. Alternative cutoffs for age were determined by log‐rank tests.

Results

The cumulative risk for LRR/SP was lower in women <60 years (5.9%, 95% confidence interval [CI] 5.3–6.6) who are under annual follow‐up than for women 60–75 (6.3%, 95% CI 5.6–7.1) receiving biennial visits. All risks were higher than the 5‐year risk of a primary tumor in the screening population (ranging from 1.4% to 1.9%). Age cutoffs <50, 50–69, and > 69 revealed better risk differentiation and would provide more risk‐based schedules. Still, other factors, including systemic treatments, had an even greater impact on recurrence risks.

Conclusion

The current consensus‐based recommendations use suboptimal age cutoffs. The proposed alternative cutoffs will lead to a more balanced risk‐based follow‐up and thereby more efficient allocation of resources. However, more factors should be taken into account for truly individualizing follow‐up based on risk for recurrence.

Implications for Practice

The current age‐based recommendations for breast cancer follow‐up after 5 years are suboptimal and do not reflect the actual risk of recurrent disease. This results in situations in which women with higher risks actually receive less follow‐up than those with a lower risk of recurrence. Alternative cutoffs could be a start toward risk‐based follow‐up and thereby more efficient allocation of resources. However, age, or any single risk factor, is not able to capture the risk differences and therefore is not sufficient for determining follow‐up. More risk factors should be taken into account for truly individualizing follow‐up based on the risk for recurrence.

Actual survival benefits related to the intensive follow‐up recommendations of current guidelines for patients with breast cancer are unclear. This article analyses long‐term breast cancer recurrence patterns to determine how the current age‐based recommendations on follow‐up schedules after 5 years correspond to the actual risk of locoregional recurrence and second primary breast cancer. Alternative guidelines are proposed.

Multifocality in ipsilateral breast tumor recurrence - A study in ablative specimens

BACKGROUND

The incidence and clinical significance of multifocality in ipsilateral breast tumor recurrence (IBTR) after breast-conserving therapy (BCT) are unclear. With growing interest in repeat BCT, this information has become of importance. This study aimed to gain insight in the incidence of multifocality in IBTR, to identify patient- and tumor-related predicting factors and to investigate the prognostic significance of multifocality.

METHODS

Two hundred and fifteen patients were included in this analysis. All had an IBTR after BCT and were treated by salvage mastectomy and appropriate adjuvant therapy. Predictive tumor- and patient-related factors for multifocality in IBTR were identified using X2 test and univariate logistic regression analyses. Prognostic outcomes were calculated using Kaplan Meier analysis and compared using the log rank test.

RESULTS

Multifocality was present in 50 (22.9%) of IBTR mastectomy specimens. Axillary positivity in IBTR was significantly associated with multifocality in IBTR. Chest wall re-recurrences occurred more often after multifocal IBTR (14% versus 7% after unifocal IBTR, p = 0.120). Regional re-recurrences did not differ significantly between unifocal and multifocal IBTR (8% vs. 6%, p = 0.773). Distant metastasis after salvage surgery occurred more frequently after multifocal IBTR (15% vs. 24%, p = 0.122). Overall survival was 132 months after unifocal IBTR and 112 months after multifocal IBTR (p = 0.197).

CONCLUSION

The prevalence of multifocality in IBTR is higher than in primary breast cancer. Axillary positivity in IBTR was associated with a multifocal IBTR. Chest wall re-recurrences and distant metastasis were, although not statistically significant, more prevalent after multifocal IBTR.

Diagnostic performance of standard breast MRI compared to dedicated axillary MRI for assessment of node-negative and node-positive breast cancer

Objectives

To investigate whether breast MRI has comparable diagnostic performance as dedicated axillary MRI regarding assessment of node-negative and node-positive breast cancer.

Methods

Forty-seven patients were included. All had undergone both breast MRI and dedicated axillary MRI, followed by surgery. All included breast MRI exams had complete field of view (FOV) of the axillary region. First, unenhanced T2-weighted (T2W) and subsequent diffusion-weighted (DW) images of both MRI exams were independently analyzed by two breast radiologists using a confidence scale and compared to histopathology. ADC values were measured by two researchers independently. Diagnostic performance parameters were calculated on a patient-by-patient basis.

Results

T2W breast MRI had the following diagnostic performance: sensitivity of 50.0% and 62.5%, specificity of 92.3%, PPV of 57.1% and 62.5%, NPV of 90.0% and 92.3%, and AUC of 0.72 for reader 1 and 0.78 for reader 2. T2W dedicated axillary MRI had the following diagnostic performance: sensitivity of 37.5% and 62.5%, specificity of 82.1% and 92.3%, PPV of 44.6% and 50.0%, NPV of 87.8% and 91.4%, and AUC of 0.65 for reader 1 and 0.73 for reader 2. In both evaluations, addition of DW images resulted in comparable diagnostic performance. For both breast MRI and dedicated axillary MRI, there was no significant difference between mean ADC values of benign and malignant lymph nodes.

Conclusions

T2W breast MRI with complete FOV of the axillary region has comparable diagnostic performance as T2W dedicated axillary MRI regarding assessment of node-negative and node-positive breast cancer. Optimization of T2W breast MRI protocol by including a complete FOV of the axillary region can, therefore, be recommended in clinical practice.

Key Points

• Breast MRI with complete field of view of the axillary region has comparable diagnostic performance as dedicated axillary MRI regarding assessment of node-negative and node-positive breast cancer.

• Optimization of breast MRI protocol by including a complete field of view of the axillary region is recommended in clinical practice.

• For both breast MRI and dedicated axillary MRI, DW imaging (including ADC measurements) is of no added value.

Quantifying the Mitigating Effects of Whole-Breast Radiotherapy and Systemic Treatments on Regional Recurrence Incidence Among Breast Cancer Patients

Background

Despite the potential for residual lymph node metastases after a negative or positive sentinel lymph node biopsy (SLNB), breast cancer patients rarely experience regional recurrences (RRs). This study aimed to quantify the effects of nonsurgical treatments on RR incidence among SLNB-negative (SLNB N0) breast cancer patients.

Methods

All primary SLNB N0-staged breast cancer patients with a diagnosis between 2005 and 2008 and 5-year follow-up data on recurrences were selected from the Netherlands Cancer Registry. The cumulative incidence function (CIF) for RR was calculated as the first event at 5 years, taking into account any other first-event (local or distant recurrence, contralateral breast cancer, or death) as competing risk. Cox regression analysis was used to model the cause-specific hazard of RR developing as the first event to quantify the effect of adjuvant systemic therapy and whole-breast radiotherapy (RT) on RR incidence at 5 years.

Results

The study included 13,512 patients. Of these patients, 162 experienced an RR. The CIF of RR at 5 years was 1.3% (95% confidence interval [CI], 1.1–1.5%), whereas the CIFs for death and other events were 4.4% and 9.5%, respectively. Cox regression analysis showed hazard ratios (HRs) of 0.46 (95% CI 0.33–0.64), 0.31 (95% CI 0.18–0.55), and 0.40 (95% CI 0.24–0.67) respectively for patients treated by RT as a routine part of breast-conserving therapy (BCT), chemotherapy, and hormonal therapy.

Conclusion

RT as routine part of BCT, chemotherapy, and hormonal therapy independently exerted a mitigating effect on the risk for the development of RR. The three methods at least halved the risk.

Electronic supplementary material

The online version of this article (10.1245/s10434-020-08356-2) contains supplementary material, which is available to authorized users.

Diagnostic performance of axillary ultrasound and standard breast MRI for differentiation between limited and advanced axillary nodal disease in clinically node-positive breast cancer patients

Preoperative differentiation between limited (pN1; 1–3 axillary metastases) and advanced (pN2–3; ≥4 axillary metastases) nodal disease can provide relevant information regarding surgical planning and guiding adjuvant radiation therapy. The aim was to evaluate the diagnostic performance of preoperative axillary ultrasound (US) and breast MRI for differentiation between pN1 and pN2–3 in clinically node-positive breast cancer. A total of 49 patients were included with axillary metastasis confirmed by US-guided tissue sampling. All had undergone breast MRI between 2008–2014 and subsequent axillary lymph node dissection. Unenhanced T2-weighted MRI exams were reviewed by two radiologists independently. Each lymph node on the MRI exams was scored using a confidence scale (0–4) and compared with histopathology. Diagnostic performance parameters were calculated for differentiation between pN1 and pN2–3. Interobserver agreement was determined using Cohen’s kappa coefficient. At final histopathology, 67.3% (33/49) and 32.7% (16/49) of patients were pN1 and pN2–3, respectively. Breast MRI was comparable to US in terms of accuracy (MRI reader 1 vs US, 71.4% vs 69.4%, p = 0.99; MRI reader 2 vs US, 73.5% vs 69.4%, p = 0.77). In the case of 1–3 suspicious lymph nodes, pN2–3 was observed in 30.4% on US (positive predictive value (PPV) 69.6%) and in 22.2–24.3% on MRI (PPV 75.7–77.8%). In the case of ≥4 suspicious lymph nodes, pN1 was observed in 33.3% on US (negative predictive value (NPV) 66.7%) and in 38.5–41.7% on MRI (NPV 58.3–61.5%). Interobserver agreement was considered good (k = 0.73). In clinically node-positive patients, the diagnostic performance of axillary US and breast MRI is comparable and limited for accurate differentiation between pN1 and pN2–3. Therefore, there seems no added clinical value of preoperative breast MRI regarding nodal staging in patients with positive axillary US.

Excision of both pretreatment marked positive nodes and sentinel nodes improves axillary staging after neoadjuvant systemic therapy in breast cancer

BACKGROUND

Marking the axilla with radioactive iodine seed and sentinel lymph node (SLN) biopsy have been proposed for axillary staging after neoadjuvant systemic therapy in clinically node-positive breast cancer. This study evaluated the identification rate and detection of residual disease with combined excision of pretreatment-positive marked lymph nodes (MLNs) together with SLNs.

METHODS

This was a multicentre retrospective analysis of patients with clinically node-positive breast cancer undergoing neoadjuvant systemic therapy and the combination procedure (with or without axillary lymph node dissection). The identification rate and detection of axillary residual disease were calculated for the combination procedure, and for MLNs and SLNs separately.

RESULTS

At least one MLN and/or SLN(s) were identified by the combination procedure in 138 of 139 patients (identification rate 99·3 per cent). The identification rate was 92·8 per cent for MLNs alone and 87·8 per cent for SLNs alone. In 88 of 139 patients (63·3 per cent) residual axillary disease was detected by the combination procedure. Residual disease was shown only in the MLN in 20 of 88 patients (23 per cent) and only in the SLN in ten of 88 (11 per cent), whereas both the MLN and SLN contained residual disease in the remainder (58 of 88, 66 per cent).

CONCLUSION

Excision of the pretreatment-positive MLN together with SLNs after neoadjuvant systemic therapy in patients with clinically node-positive disease resulted in a higher identification rate and improved detection of residual axillary disease.

Contrast-enhanced spectral mammography in the evaluation of breast suspicious calcifications: diagnostic accuracy and impact on surgical management

Background

Detecting pathological breast calcifications remains challenging. Based on recent studies, contrast-enhanced spectral mammography (CESM) was shown to be superior compared to full-field digital mammography (FFDM).

Purpose

To evaluate the diagnostic accuracy of CESM in suspicious breast calcifications and its impact on surgical decision-making.

Material and Methods

All screening recalled patients with suspicious calcifications that underwent CESM in the period October 2012 until September 2015 were included. One experienced radiologist provided a BI-RADS classification for the FFDM images only. The evaluation was repeated for the CESM exam. In a simulated tumor board meeting, two breast surgeons decided on the preferred surgical treatment (breast conservation therapy [BCT] versus mastectomy) for all malignant cases. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated defining BI-RADS ≥4 as being malignant. In addition, differences in surgical decision-making were analyzed and compared using McNemar’s test.

Results

In total, 147 women were included in this study (mean age = 61 years; age range = 49–75 years). Pathology showed 82 benign and 65 malignant lesions, of which 33 were ductal carcinomas in situ and 32 were invasive lesions. Diagnostic performances of CESM (differences compared to FFDM in brackets) were: sensitivity 93.8% (+3%), specificity 36.6% (−2.5%), PPV 54% (0%), and NPV 88.2% (+4%). Based on low-energy images, surgeons suggested BCT in 89% of the cases. Based on the CESM exam, no statistical changes in decisions were observed (86% BCT, P = 0.453).

Conclusion

CESM only slightly improves the diagnostic accuracy of the evaluation of breast calcifications. It is not of added value compared to FFDM in guiding surgical decision-making.

The Clinical Link between Human Intestinal Microbiota and Systemic Cancer Therapy

Clinical interest in the human intestinal microbiota has increased considerably. However, an overview of clinical studies investigating the link between the human intestinal microbiota and systemic cancer therapy is lacking. This systematic review summarizes all clinical studies describing the association between baseline intestinal microbiota and systemic cancer therapy outcome as well as therapy-related changes in intestinal microbiota composition. A systematic literature search was performed and provided 23 articles. There were strong indications for a close association between the intestinal microbiota and outcome of immunotherapy. Furthermore, the development of chemotherapy-induced infectious complications seemed to be associated with the baseline microbiota profile. Both chemotherapy and immunotherapy induced drastic changes in gut microbiota composition with possible consequences for treatment efficacy. Evidence in the field of hormonal therapy was very limited. Large heterogeneity concerning study design, study population, and methods used for analysis limited comparability and generalization of results. For the future, longitudinal studies investigating the predictive ability of baseline intestinal microbiota concerning treatment outcome and complications as well as the potential use of microbiota-modulating strategies in cancer patients are required. More knowledge in this field is likely to be of clinical benefit since modulation of the microbiota might support cancer therapy in the future.

Risk of Positive Sentinel Lymph Node After Neoadjuvant Systemic Therapy in Clinically Node-Negative Breast Cancer: Implications for Postmastectomy Radiation Therapy and Immediate Breast Reconstruction

Background

Residual axillary lymph node involvement after neoadjuvant systemic therapy (NST) is the determining factor for postmastectomy radiation therapy (PMRT). Preoperative identification of patients needing PMRT is essential to enable shared decision-making when choosing the optimal timing of breast reconstruction. We determined the risk of positive sentinel lymph node (SLN) after NST in clinically node-negative (cN0) breast cancer.

Methods

All cT1-3N0 patients treated with NST followed by mastectomy and SLNB between 2010 and 2016 were identified from the Netherlands Cancer Registry. Rate of positive SLN for different breast cancer subtypes was determined. Logistic regression analysis was performed to determine correlated clinicopathological variables with positive SLN.

Results

In total 788 patients were included, of whom 25.0% (197/788) had positive SLN. cT1-3N0 ER+HER2+, cT1-3N0 ER−HER2+ , and cT1-2N0 triple-negative patients had the lowest rate of positive SLN: 7.2–11.5%, 0–6.3%, and 2.9–6.2%, respectively. cT1-3N0 ER+HER2− and cT3N0 triple-negative patients had the highest rate of positive SLN: 23.8–41.7% and 30.4%, respectively. Multivariable regression analysis showed that cT2 (odds ratio [OR] 1.93; 95% confidence interval [CI] 1.01–3.96), cT3 (OR 2.56; 95% CI 1.30–5.38), grade 3 (OR 0.44; 95% CI 0.21–0.91), and ER+HER2− subtype (OR 3.94; 95% CI 1.77–8.74) were correlated with positive SLN.

Conclusions

In cT1-3N0 ER+HER2+, cT1-3N0 ER−HER2+, and cT1-2N0 triple-negative patients treated with NST, immediate reconstruction can be considered an acceptable option due to low risk of positive SLN. In cT1-3N0 ER+HER2− and cT3N0 triple-negative patients treated with NST, risks and benefits of immediate reconstruction should be discussed with patients due to the relatively high risk of positive SLN.