Reproducibility of residual cancer burden for prognostic assessment of breast cancer after neoadjuvant chemotherapy

Prognostic factors of patients with human epidermal growth factor receptor 2-positive breast cancer following neoadjuvant therapy: Development and validation of a predictive nomogram

OBJECTIVE

Human epidermal growth factor receptor 2 (HER2)-positive breast cancer exhibits an aggressive phenotype and poor prognosis. The application of neoadjuvant therapy (NAT) in patients with breast cancer can significantly reduce the risks of disease recurrence and improve survival. By integrating different clinicopathological factors, nomograms are valuable tools for prognosis prediction. This study aimed to assess the prognostic value of clinicopathological factors in patients with HER2-positive breast cancer and construct a nomogram for outcome prediction.

METHODS

We retrospectively analyzed the clinicopathological data from 374 patients with breast cancer admitted to the Fourth Hospital of Hebei Medical University between January 2009 and December 2017, who were diagnosed with invasive breast cancer through preoperative core needle biopsy pathology, underwent surgical resection after NAT, and were HER2-positive. Patients were randomly divided into a training and validation set at a ratio of 7:3. Univariate and multivariate survival analyses were performed using Kaplan-Meier and Cox proportional hazards regression models. Results of the multivariate analysis were used to create nomograms predicting 3-, 5-, and 8-year overall survival (OS) rates. Calibration curves were plotted to test concordance between the predicted and actual risks. Harrell C-index and time-dependent receiver operating characteristic (ROC) curves were used to evaluate the discriminability of the nomogram prediction model.

RESULTS

All included patients were women, with a mean age of 50 ± 10.4 years (range: 26-72 years). In the training set, both univariate and multivariate analyses identified residual cancer burden (RCB) class, tumor-infiltrating lymphocytes(TILs), and clinical stage as independent prognostic factors for OS, and these factors were combined to construct a nomogram. The calibration curves demonstrated good concordance between the predicted and actual risks, and the C-index of the nomogram was 0.882 (95 % CI 0.863-0.901). The 3-, 5-, and 8-year areas under the ROC curve (AUCs) were 0.909, 0.893, and 0.918, respectively, indicating good accuracy of the nomogram. The calibration curves also demonstrated good concordance in the validation set, with a C-index of 0.850 (95 % CI 0.804-0.896) and 3-, 5-, and 8-year AUCs of 0.909, 0.815, and 0.834, respectively, which also indicated good accuracy.

CONCLUSION

The nomogram prediction model accurately predicted the prognostic status of post-NAT patients with breast cancer and was more accurate than clinical stage and RCB class. Therefore, it can serve as a reliable guide for selecting clinical treatment measures for breast cancer.

Invasive lobular carcinoma of the breast; clinicopathologic profile and response to neoadjuvant chemotherapy over a 15-year period

INTRODUCTION

Invasive lobular carcinoma (ILC) accounts for 5-15% of invasive breast cancers. Typical ILC is oestrogen receptor (ER) positive and human epidermal growth factor receptor 2 (HER2) negative. Atypical biomarker profiles (ER- and HER2+, ER+ and HER2+ or triple negative) appear to differ from typical ILCs. This study compared subtypes of ILC in terms of clinical and pathological parameters, and response to neoadjuvant chemotherapy (NACT) according to biomarker profile.

METHODS

All patients with ILC treated in a single centre from January 2005 to December 2020 were identified from a prospectively maintained database. Clinicopathologic and outcome data was collected and analysed according to tumour biomarker profile.

RESULTS

A total of 582 patients with ILC were treated. Typical ILC was observed in 89.2% (n = 519) and atypical in 10.8% (n = 63). Atypical ILCs were of a higher grade (35% grade 3 vs 9.6% grade 3, p < 0.001). A larger proportion of atypical ILC received NACT (31.7% vs 6.9% p < 0.001). Atypical ILCs showed a greater response to NACT (mean RCB (Residual Cancer Burden Score) 2.46 vs mean RCB 3.41, p = 0.0365), and higher pathological complete response rates (15% vs 0% p = 0.017). Despite this, overall 5-year disease-free survival (DFS) was higher in patients with typical ILC (91% vs 83%, p = 0.001).

CONCLUSIONS

Atypical ILCs have distinct characteristics. They are more frequently of a higher grade and demonstrate a superior response to NACT. Despite the latter, atypical ILCs have a worse 5-year DFS which should be taken into consideration in terms of prognostication and may assist patient selection for NACT.

Impact of Presenting Stage on Overall Survival in Patients Treated with Neoadjuvant Chemotherapy for Triple Negative Breast Cancer

PURPOSE

For operable triple-negative breast cancer (TNBC) treated with neoadjuvant chemotherapy (NAC), clinical prognostication and postoperative decision-making relies exclusively on whether a pathologic complete response (pCR) is achieved or not. We evaluated whether extent of disease at presentation further influenced overall survival (OS) among patients with pCR or with residual disease (RD) following NAC.

METHODS

Patients with stage I-III TNBC who underwent NAC were identified from the National Cancer Database from 2010 to 2019. Overall survival was assessed by disease extent using the Kaplan-Meier method and Cox proportional hazards regression for univariate and multivariable analysis.

RESULTS

A total of 35,598 patients met inclusion criteria, and 11,967 achieved pCR. Ten-year OS was 88.5% and varied by cT and cN category at presentation. Best 10-year OS was seen in patients with cT1-2, cN0 (90.9%) and was worst in those with cT3-4, cN2-3 disease (72.0%). A total of 23,631 patients had RD. Ten-year OS was 60.1% and varied by cT and cN category at presentation. Best 10-year OS was seen in patients with cT1-2, cN0 (73.0%) and was worst in those with cT3-4, cN2-3 disease (36.3%). Notably, OS was significantly poorer for patients with cT3-4, cN2-3 disease at diagnosis and pCR versus those with cT1-2 cN0 and RD (aHR 1.30, 95% confidence interval 1.03-1.63, p = 0.03).

CONCLUSIONS

Among patients with TNBC, extent of disease at presentation was prognostic for OS independently of response to NAC. Patients with advanced stage at presentation had poorer OS even in the context of pCR. Further investigation is needed to evaluate whether additional adjuvant therapy strategies should be considered for these patients.

New Emerging Chemokine Receptors: CCR5 or CXCR5 on Tumor Is Associated with Poor Response to Chemotherapy and Poor Prognosis in Locally Advanced Triple-Negative Breast Cancer

BACKGROUND

We aim to investigate any possible associations between chemokine receptor expression and responses to neoadjuvant chemotherapy (NAC) along with outcomes in patients with triple-negative breast cancer (TNBC) with locally advanced disease.

METHOD

Expressions of chemokine receptors were examined immunohistochemically after staining archival tissue of surgical specimens (n = 63) using specific antibodies for CCR5, CCR7, CXCR4, and CXCR5.

RESULTS

Patients with high CCR5, CCR7, CXCR4, and CXCR5 expression on tumors and high CXCR4 expression on tumor-infiltrating lymphocytes (TILs) were less likely to have a pathological complete response (pCR) or Class 0-I RCB-Index compared to others. Patients with residual lymph node metastases (ypN-positive), high CCR5TM(tumor), and high CXCR4TM expressions had an increased hazard ratio (HR) compared to others (DFS: HR = 2.655 [1.029-6.852]; DSS: HR = 2.763 [1.008-7.574]), (DFS: HR = 2.036 [0.805-5.148]; DSS: HR = 2.689 [1.020-7.090]), and (DFS: HR = 2.908 [1.080-7.829]; DSS: HR = 2.132 (0.778-5.846)), respectively. However, patients without CXCR5TIL expression had an increased HR compared to those with CXCR5TIL (DFS: 2.838 [1.266-6.362]; DSS: 4.211 [1.770-10.016]).

CONCLUSIONS

High expression of CXCR4TM and CCR5TM was found to be associated with poor prognosis, and CXCR5TM was associated with poor chemotherapy response in the present cohort with locally advanced TNBC. Our results suggest that patients with TNBC could benefit from a chemokine receptor inhibitor therapy containing neoadjuvant chemotherapy protocols.

A dedicated structured data set for reporting of invasive carcinoma of the breast in the setting of neoadjuvant therapy: recommendations from the International Collaboration on Cancer Reporting (ICCR)

AIMS

The International Collaboration on Cancer Reporting (ICCR), a global alliance of major (inter-)national pathology and cancer organisations, is an initiative aimed at providing a unified international approach to reporting cancer. ICCR recently published new data sets for the reporting of invasive breast carcinoma, surgically removed lymph nodes for breast tumours and ductal carcinoma in situ, variants of lobular carcinoma in situ and low-grade lesions. The data set in this paper addresses the neoadjuvant setting. The aim is to promote high-quality, standardised reporting of tumour response and residual disease after neoadjuvant treatment that can be used for subsequent management decisions for each patient.

METHODS

The ICCR convened expert panels of breast pathologists with a representative surgeon and oncologist to critically review and discuss current evidence. Feedback from the international public consultation was critical in the development of this data set.

RESULTS

The expert panel concluded that a dedicated data set was required for reporting of breast specimens post-neoadjuvant therapy with inclusion of data elements specific to the neoadjuvant setting as core or non-core elements. This data set proposes a practical approach for handling and reporting breast resection specimens following neoadjuvant therapy. The comments for each data element clarify terminology, discuss available evidence and highlight areas with limited evidence that need further study. This data set overlaps with, and should be used in conjunction with, the data sets for the reporting of invasive breast carcinoma and surgically removed lymph nodes from patients with breast tumours, as appropriate. Key issues specific to the neoadjuvant setting are included in this paper. The entire data set is freely available on the ICCR website.

CONCLUSIONS

High-quality, standardised reporting of tumour response and residual disease after neoadjuvant treatment are critical for subsequent management decisions for each patient.

Ultrasound-based radiomics-clinical nomogram for noninvasive prediction of residual cancer burden grading in breast cancer

PURPOSE

To assess the predictive value of an ultrasound-based radiomics-clinical nomogram for grading residual cancer burden (RCB) in breast cancer patients.

METHODS

This retrospective study of breast cancer patients who underwent neoadjuvant therapy (NAC) and ultrasound scanning between November 2020 and July 2023. First, a radiomics model was established based on ultrasound images. Subsequently, multivariate LR (logistic regression) analysis incorporating both radiomic scores and clinical factors was performed to construct a nomogram. Finally, Receiver operating characteristics (ROC) curve analysis and decision curve analysis (DCA) were employed to evaluate and validate the diagnostic accuracy and effectiveness of the nomogram.

RESULTS

A total of 1122 patients were included in this study. Among them, 427 patients exhibited a favorable response to NAC chemotherapy, while 695 patients demonstrated a poor response to NAC therapy. The radiomics model achieved an AUC value of 0.84 in the training cohort and 0.83 in the validation cohort. The ultrasound-based radiomics-clinical nomogram achieved an AUC value of 0.90 in the training cohort and 0.91 in the validation cohort.

CONCLUSIONS

Ultrasound-based radiomics-clinical nomogram can accurately predict the effectiveness of NAC therapy by predicting RCB grading in breast cancer patients.

Event-free survival by residual cancer burden with pembrolizumab in early-stage TNBC: exploratory analysis from KEYNOTE-522

BACKGROUND

KEYNOTE-522 demonstrated statistically significant improvements in pathological complete response (pCR) with neoadjuvant pembrolizumab plus chemotherapy and event-free survival (EFS) with neoadjuvant pembrolizumab plus chemotherapy followed by adjuvant pembrolizumab in patients with high-risk, early-stage triple-negative breast cancer (TNBC). Prior studies have shown the prognostic value of the residual cancer burden (RCB) index to quantify the extent of residual disease after neoadjuvant chemotherapy. In this preplanned exploratory analysis, we assessed RCB distribution and EFS within RCB categories by treatment group.

PATIENTS AND METHODS

A total of 1174 patients with stage T1c/N1-2 or T2-4/N0-2 TNBC were randomized 2 : 1 to pembrolizumab 200 mg or placebo every 3 weeks given with four cycles of paclitaxel + carboplatin, followed by four cycles of doxorubicin or epirubicin + cyclophosphamide. After surgery, patients received pembrolizumab or placebo for nine cycles or until recurrence or unacceptable toxicity. Primary endpoints are pCR and EFS. RCB is a prespecified exploratory endpoint. The association between EFS and RCB was assessed using a Cox regression model.

RESULTS

Pembrolizumab shifted patients into lower RCB categories across the entire spectrum compared with placebo. There were more patients in the pembrolizumab group with RCB-0 (pCR), and fewer patients in the pembrolizumab group with RCB-1, RCB-2, and RCB-3. The corresponding hazard ratios (95% confidence intervals) for EFS were 0.70 (0.38-1.31), 0.92 (0.39-2.20), 0.52 (0.32-0.82), and 1.24 (0.69-2.23). The most common first EFS events were distant recurrences, with fewer in the pembrolizumab group across all RCB categories. Among patients with RCB-0/1, more than half [21/38 (55.3%)] of all events were central nervous system recurrences, with 13/22 (59.1%) in the pembrolizumab group and 8/16 (50.0%) in the placebo group.

CONCLUSIONS

Addition of pembrolizumab to chemotherapy resulted in fewer EFS events in the RCB-0, RCB-1, and RCB-2 categories, with the greatest benefit in RCB-2. These findings demonstrate that pembrolizumab not only increased pCR rates, but also improved EFS among most patients who do not have a pCR.

The Impact of Different Patterns of Residual Disease on Long-Term Oncological Outcomes in Breast Cancer Patients Treated with Neo-Adjuvant Chemotherapy

BACKGROUNDS

The majority of breast cancer (BC) patients treated with neo-adjuvant chemotherapy (NAC) achieves a pathologic partial response with different patterns of residual disease. No clear correlation between these patterns and oncological results was described. Our aims were to define the predictive factors for different patterns of residual disease and compare the outcomes between the scattered versus the circumscribed pattern.

METHODS

We reviewed 219 postoperative surgical specimens. Patients were divided into two groups: scattered versus circumscribed. Disease-free survival (DFS), distant DFS (DDFS), and overall survival (OS) were analyzed.

RESULTS

The scattered and circumscribed patterns were assessed in 111 (50.7%) and 108 (49.3%) patients. Two independent predictive factors for the circumscribed pattern were identified: discontinuation of NAC cycles (p = 0.011), and tumor size post-NAC >18 mm (p = 0.022). No difference was observed in terms of DFS and DDFS. Patients with the scattered pattern exhibited a statistically significant better OS. Discontinuation of NAC cycles, tumor size >18 mm, triple-negative BC, and ypN+ were associated with increased recurrence and poorer survival.

CONCLUSIONS

Discontinuation of NAC cycles and tumor size are independent factors associated with patterns of residual disease. The scattered pattern presents better survival. Understanding the relationship between NAC, the residual pattern, and differences in survival outcomes offers the potential to optimize the therapeutic approaches.

A Prognostic Model Based on Residual Cancer Burden and Tumor-Infiltrating Lymphocytes on Residual Disease after Neoadjuvant Therapy in HER2+ Breast Cancer

PURPOSE

We aim to evaluate the prognostic significance of tumor-infiltrating lymphocyte on residual disease (RD-TIL) in HER2+ patients with breast cancer who failed to achieve pathologic complete response (pCR) after anti-HER2+ chemotherapy (CT)-based neoadjuvant treatment (NAT). We assessed the feasibility of combining the prognostic information provided by residual cancer burden (RCB) and RD-TILs into a composite score (RCB+TIL).

EXPERIMENTAL DESIGN

HER2+ patients with breast cancer treated with CT+anti-HER2-based NAT at three institutions were retrospectively included. RCB and TIL levels were evaluated on hematoxylin and eosin-stained slides from surgical samples according to available recommendations. Overall survival (OS) was used as an outcome measure.

RESULTS

A total of 295 patients were included, of whom 195 had RD. RCB was significantly associated with OS. Higher RD-TILs were significantly associated with poorer OS as compared with lower RD-TILs (15% cutoff). In multivariate analysis, both RCB and RD-TIL maintained their independent prognostic value. A combined score, RCB+TIL, was calculated from the estimated coefficient of RD-TILs and the RCB index in a bivariate logistic model for OS. The RCB+TIL score was significantly associated with OS. The C-index for OS of the RCB+TIL score was numerically higher than that of RCB and significantly higher than that of RD-TILs.

CONCLUSIONS

We have reported an independent prognostic impact of RD-TILs after anti-HER2+CT NAT, which might underlie an imbalance of the RD microenvironment towards immunosuppressive features. We provided a new composite prognostic score based on RCB+TIL, which was significantly associated with OS and proved to be more informative than the isolated evaluation of RCB and RD-TILs.

The immune microenvironment characterisation and dynamics in hormone receptor-positive breast cancer before and after neoadjuvant endocrine therapy

BACKGROUND

Oestrogen receptor positive (ER+)/HER-2 negative breast cancer (BC) is considered to be an immunologically cold tumour compared to triple negative breast cancer. Therefore, the tumour microenvironment (TME) of ER+/HER-2 negative BC is understudied. The aim of this project is to investigate the TME and the immune response during neoadjuvant endocrine therapy (NET) and to correlate this with the treatment response in a real life setting.

METHODS

Expression of immune checkpoint receptors and immune cells was examined immunohistochemically, pre- and post-NET in a cohort of 56 ER+/HER-2 negative BC patients. They were treated with tamoxifen (n = 16), an aromatase inhibitor (n = 40) or a combination of an aromatase inhibitor with a PI3K inhibitor (n = 11) for a median duration of 6 months (range 1-32 months). Immunohistochemical staining with monoclonal antibodies for PDL-1, PD-1, TIM-3, LAG-3, CTLA-4, CD4, CD68 and FOXP3 were performed. All staining procedures were done according to validated protocols, and scoring was done by a pathologist specialized in breast cancer. Positivity was defined as staining >1% on TILs. Response to NET was evaluated according to tumour size change on imaging and Ki-67 change.

RESULTS

The median age was 61.02 (37-90) years. Diameter of tumour size decreased with a mean of 8.1 mm (-16 mm to 45 mm) (p < 0.001) during NET and the value of Ki-67 value decreased with a median of 9 after NET (p < 0.001). An increase in PD-L1 expression after NET showed a trend towards significant (p = 0.088) and CD-4+ T cells significantly increased after NET (p = 0.03). A good response to NET defined as a decrease in tumour size and/or decrease of Ki-67 was found to be associated with a longer duration of NET, a change of CD4+ T-cells and a higher number of CD68+ tumour-associated macrophages before the start of NET.

CONCLUSION

The immune microenvironment plays an important role in ER+/HER-2 negative BC. NET influences the composition and functional state of the infiltrating immune cells. Furthermore, changes in the immune microenvironment are also associated with treatment response.

Matrix Metalloproteinase-9 Expression Is Associated with the Absence of Response to Neoadjuvant Chemotherapy in Triple-Negative Breast Cancer Patients

Triple-negative breast cancer (TNBC) is particularly challenging due to the weak or absent response to therapeutics and its poor prognosis. The effectiveness of neoadjuvant chemotherapy (NAC) response is strongly influenced by changes in elements of the tumor microenvironment (TME). This work aimed to characterize the residual TME composition in 96 TNBC patients using immunohistochemistry and in situ hybridization techniques and evaluate its prognostic implications for partial responders vs. non-responders. Compared with non-responders, partial responders containing higher levels of CD83+ mature dendritic cells, FOXP3+ regulatory T cells, and IL-15 expression but lower CD138+ cell concentration exhibited better OS and RFS. However, along with tumor diameter and positive nodal status at diagnosis, matrix metalloproteinase-9 (MMP-9) expression in the residual TME was identified as an independent factor associated with the impaired response to NAC. This study yields new insights into the key components of the residual tumor bed, such as MMP-9, which is strictly associated with the lack of a pathological response to NAC. This knowledge might help early identification of TNBC patients less likely to respond to NAC and allow the establishment of new therapeutic targets.

Good practice: The experiences with the utilization of residual cancer burden-A single institution study

INTRODUCTION

The use of neoadjuvant therapy (NAT) has been showing an incraesing tendency in the treatment of locally advanced breast cancer. The evaluation of residual cancer could be performed by Residual Cancer Burden (RCB) calculator. The prognostic system takes the two largest diameters of the tumor, the cellularity, the amount of in situ carcinoma, the number of metastatic lymph nodes, and the size of the largest metastatic deposit into account. The aim of our study was to examine the reproducibility of RCB in NAT treated patients.

METHODS

Patients who were treated with NAT and had resection specimens between 2018 and 2021 were selected. Histological examination was performed by five pathologists. After assessment of the examined variables, RCB points and RCB classes were defined. For statistical analysis, interclass correlation was used (SPSS Statistics V.22.0 software).

RESULTS

Altogether 100 patients were included in our retrospective, cohort study (average age: 57 years). In two-thirds of the cases, third generation chemotherapy was used, and mastectomy was performed. Significant concordance was found in the two largest diameters of the tumor (coefficients, 0.984 and 0.973), the cellularity (coefficient, 0.970), and the largest metastatic deposit (coefficient, 0.998). Although the amount of in situ carcinoma proved to be the least reproducible factor, it resulted in almost 90% of agreement (coefficient, 0.873). Regarding RCB points and classes, similar results were observed (coefficients, 0.989 and 0.960).

CONCLUSIONS

Significant agreement was observed between examiners based on almost all RCB parameters, points, and classes, reflecting the optimal reproducibility of RCB. Therefore, we recommend the use of the calculator in routine histopathological reports in NAT cases.

Breast Cancer With a HER2 FISH Group 2 Result: Should HER2 Tests be Repeated?

BACKGROUND

Breast cancer with fluorescence in situ hybridization (FISH) group 2 pattern (HER2 <4 and HER2/CEP17 ratio ≥2, a subset of monosomy CEP17) was historically considered HER2-positive, but mostly HER2-negative according to updated 2018 American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines unless 3+ by immunohistochemistry (IHC). Therapeutic relevance of this group remained elusive, therefore we assessed if repeat IHC and FISH can assist final HER2 classification.

PATIENT AND METHODS

We retrospectively reviewed HER2 FISH performed at our institution from 2014 to 2018 and identified 23 of 3554 (0.6%) breast cancer cases with at least one-time measurement of HER2 FISH categorized as group 2. Repeat HER2 tests were performed for cases with available alternative tumor samples and compared with initial testing following 2018 ASCO/CAP guidelines.

RESULTS

Only 1 of 23 group 2 cases was HER2-positive, 0/18 in primary and 1/5 in metastatic/recurrent tumors. Of 13 primary tumors with repeat HER2 results; 10 (77%) remained HER2-negative; 3 (23%) changed from HER2-negative (group 2 and IHC 2+) to HER2-positive (group 1 and IHC 2+). Among 8 of these 13 patients receiving neoadjuvant systemic therapy containing anti-HER2 agent, 3 (38%) achieved pathologic complete response (pCR). Two of 3 pCR cases were HER2-positive converters on repeat testing. Three pCR cases were ER-negative or -low positive and Ki67 ≥40%, while 5 partial responders were ER-positive and Ki67 <40% (P < .05).

CONCLUSION

Breast cancer with HER2 FISH group 2 result may represent heterogeneous populations of tumor cells being originated de novo or preferentially selected secondary to therapy. Repeat HER2 tests on alternative samples may be considered to guide anti-HER2 therapy.

Exploring Real-World HER2-Low Data in Early-Stage Triple-Negative Breast Cancer: Insights and Implications

Purpose

This study aimed to compare the clinical behavior, clinicopathological and sociodemographic characteristics of patients with early-stage triple-negative breast cancer (TNBC) who belong to the HER2-low and HER2-zero subgroups.

Patients and Methods

This study involved a thorough search in the internal database of a single Brazilian institution to identify women with TNBC who underwent neoadjuvant chemotherapy (NACT) followed by curative surgery within the period from January 2010 to December 2014. HER2 analysis through immunohistochemistry (IHC) and, if required, amplification by in situ hybridization, was conducted using core biopsy samples. The study assesses outcomes of residual cancer burden (RCB), event-free survival (EFS), and overall survival (OS).

Results

A total of 170 cases were analyzed, with a mean age of 51.4 years (standard deviation, SD 11.2). The HER2 status was categorized as IHC 0, 1+, or 2+ in 80 (47.1%), 73 (42.9%), and 17 (10%) patients, respectively. No significant differences were observed in the prevalence of clinical pathological characteristics among the subgroups. The absence of significant results for clinicopathological and demographic features hindered the multivariate analysis of HER2 subgroups. Similarly, no significant differences were found in the RCB, EFS, and OS outcomes between HER2 subgroups.

Conclusion

The findings of this study suggest that, in early-stage TNBC, the clinical behavior and survival outcomes of the HER2-low subgroup may not differ significantly from those of the HER2-zero subgroup.

Does Residual Cancer Burden Predict Local Recurrence After Neoadjuvant Chemotherapy?

BACKGROUND

The extent of residual disease after neoadjuvant chemotherapy (NAC) can be quantified by the Residual Cancer Burden (RCB), a prognostic tool used to estimate survival outcomes in breast cancer. This study investigated the association between RCB and locoregional recurrence (LRR).

METHODS

The study reviewed 532 women with breast cancer who underwent NAC between 2010 and 2016. Relapse in the ipsilateral breast, skin/subcutis at the surgical site, chest wall, pectoralis, or regional lymph nodes defined an LRR. The LRR cumulative incidence (LRCI) was estimated using the Fine and Gray competing-risks model, with death and distant recurrence defined as competing events. The association of LRCI with prognostic variables was evaluated.

RESULTS

Overall, 5.5% of the patients experienced an LRR after a median follow-up period of 65 months. The 5-year LRCI rates by RCB were as follows: RCB-0 (0.9%), RCB-1 (3.2%), RCB-2 (6.0%), and RCB-3 (12.9%). In the univariable analysis, LRCI varied significantly by RCB (p = 0.010). The multivariable analysis showed a significant association of LRCI with increasing RCB, and the patients with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) phenotype were at lower risk for LRR than those with HER2+ and triple-negative cancers (p < 0.032). The patients with RCB-3 were at a higher risk for local relapse than those with RCB-0 (hazard ratio, 13.78; confidence interval, 2.25-84.45; p = 0.04). Type of operation (p = 0.04) and use of adjuvant radiation (p = 0.046) were statistically significant in the multivariable model.

CONCLUSIONS

The study results demonstrate a significant association between LRCI and increasing RCB, although distant recurrence is a substantial driver of disease outcomes. Future prospective studies should examine the role of RCB in clinical decisions regarding indications for adjuvant therapy.

"No Ink on Tumor" in Breast-Conserving Surgery after Neoadjuvant Chemotherapy

Background/Aim: Patients with Stage I-II breast cancer undergoing breast-conserving surgery after neoadjuvant chemotherapy (BCS-NAC) were retrospectively assessed in order to evaluate the extent of a safe excision margin. Materials and Methods: Between 2003 and 2020, 151 patients underwent risk-adapted BCS-NAC; margin involvement was always assessed at definitive histology. Patients with complete pathological response (pCR) were classified as the RX group, whereas those with residual disease and negative margins were stratified as R0 < 1 mm (margin < 1 mm) and R0 > 1 mm (margin > 1 mm). Results: Totals of 29 (19.2%), 64 (42.4%), and 58 patients (38.4%) were included in the R0 < 1 mm, R0 > 1 mm, and RX groups, respectively, and 2 patients with margin involvement had a mastectomy. Ten instances of local recurrence (6.6%) occurred, with no statistically significant difference in local recurrence-free survival (LRFS) between the three groups. A statistically significant advantage of disease-free survival (p = 0.002) and overall survival (p = 0.010) was observed in patients with pCR. Conclusions: BCS-NAC was increased, especially in HER-2-positive and triple-negative tumors; risk-adapted BCS should be preferably pursued to highlight the cosmetic benefit of NAC. The similar rate of LRFS in the three groups of patients suggests a shift toward the “no ink on tumor” paradigm for patients undergoing BCS-NAC.

The association between breast density and breast cancer pathological response to neoadjuvant chemotherapy

Purpose

Mammographic Density (MD) refers to the amount of fibroglandular breast tissue present in the breast and is an established risk factor for developing breast cancer. The ability to evaluate treatment response dynamically renders neoadjuvant chemotherapy (NACT) the preferred treatment option in many clinical scenarios. Previous studies have suggested that MD can predict patients likely to achieve a pathological complete response (pCR) to NACT. We aimed to determine whether there is a causal relationship between BI-RADS breast composition categories for breast density at diagnosis and the pCR rate and residual cancer burden score (RCB) by performing a retrospective review on consecutive breast cancer patients who received NACT in a tertiary referral centre from 2015 to 2021.

Methods

The Mann–Whitney U Test was used to test for differences between two independent groups (i.e. those who achieved pCR and those who did not). A binary logistic regression model was used to estimate odds ratios (OR) and corresponding 95% confidence intervals (CI) for an association between the independent variables of molecular subtype, MD, histological grade and FNA positivity and the dependant variable of pCR. Statistical analysis was conducted with SPSS (IBM SPSS for Mac, Version 26.0; IBM Corp).

Results

292 patients were included in the current study. There were 124, 155 and 13 patients in the BI-RADS MD category b, c and d, respectively. There were no patients in the BI-RADS MD category a. The patients with less dense breast composition (MD category b) were significantly older than patients with denser breast composition (MD category c, d) (p = 0.001) and patients who had a denser breast composition (MD category d) were more likely to have ER+ tumours. There was no significant difference in PgR status, HER2 status, pathological complete response (pCR), FNA positivity, or RCB class dependent upon the three MD categories. A binary logistic regression revealed that patients with HER2-enriched breast cancer and triple-negative breast cancer are more likely to achieve pCR with an OR of 3.630 (95% CI 1.360–9.691, p = 0.010) and 2.445 (95% CI 1.131–5.288, p = 0.023), respectively.

Conclusion

Whilst dense MD was associated with ER positivity and these women were less likely to achieve a pCR, MD did not appear to independently predict pCR post-NACT.

Reconstructing virtual large slides can improve the accuracy and consistency of tumor bed evaluation for breast cancer after neoadjuvant therapy

BACKGROUND

To explore whether the "WSI Stitcher", a program we developed for reconstructing virtual large slide through whole slide imaging fragments stitching, can improve the efficiency and consistency of pathologists in evaluating the tumor bed after neoadjuvant treatment of breast cancer compared with the conventional methods through stack splicing of physical slides.

METHODS

This study analyzed the advantages of using software-assisted methods to evaluate the tumor bed after neoadjuvant treatment of breast cancer. This new method is to use "WSI Stitcher" to stitch all the WSI fragments together to reconstruct a virtual large slide and evaluate the tumor bed with the help of the built-in ruler and tumor proportion calculation functions.

RESULTS

Compared with the conventional method, the evaluation time of the software-assisted method was shortened by 35%(P < 0.001). In the process of tumor bed assessment after neoadjuvant treatment of breast cancer, the software-assisted method has higher intraclass correlation coefficient when measuring the length (0.994 versus 0.934), width (0.992 versus 0.927), percentage of residual tumor cells (0.947 versus 0.878), percentage of carcinoma in situ (0.983 versus 0.881) and RCB index(0.997 versus 0.772). The software-assisted method has higher kappa values when evaluating tumor staging(0.901 versus 0.687) and RCB grading (0.963 versus 0.857).

CONCLUSION

The "WSI Stitcher" is an effective tool to help pathologists with the assessment of breast cancer after neoadjuvant treatment.

Neoadjuvant Therapy in Breast Cancer: Histologic Changes and Clinical Implications

Cytotoxic or endocrine therapy before surgery (neoadjuvant) for breast cancer has become standard of care, affording the opportunity to assess and quantify response in the subsequent resection specimen. Correlation with radiology, cassette mapping, and histologic review with a semi-quantitative reporting system such as residual cancer burden (RCB) provides important prognostic data that may guide further therapy. The tumor bed should be identified histologically, often as a collagenized zone devoid of normal breast epithelium, with increased vasculature. Identification of residual treated carcinoma may require careful high power examination, as residual tumor cells may be small and dyscohesive; features are widely variable and include hyperchromatic small, large, or multiple nuclei with clear, foamy, or eosinophilic cytoplasm. Calculation of RCB requires residual carcinoma span in 2 dimensions, estimated carcinoma cellularity (% area), number of involved lymph nodes, and span of largest nodal carcinoma. These RCB parameters may differ from AJCC staging measurements, which depend on only contiguous carcinoma in breast and lymph nodes.

Redirecting Chemotherapeutics to the Endoplasmic Reticulum Increases Tumor Immunogenicity and Potentiates Anti-PD-L1 Therapy

The endoplasmic reticulum (ER) in cancer cells has been considered as a pharmacological target. Still, the effects of a ER-targeted system remain less investigated, due to the fact that most chemo-drugs take actions in the nucleus. Here, it is demonstrated that ER-targeted delivery of doxorubicin (DOX), a typically nucleus-tropic-and-acting agent, attenuates its original effect on cytotoxicity while generating new functions favorable for immune activation. First, a library of DOX derivatives with variable ER-targeting abilities is synthesized. The results reveal that higher ER-targeting efficiency correlates with greater ER stress. As compared with naïve drug, ER-targeted DOX considerably alters the mode of action from nuclear DNA damage-associated cytotoxicity to ER stress-mediated calreticulin exposure. Consequently, ER-targeted DOX decreases cytotoxicity but increases the capability to induce immunogenic cell death (ICD). Therefore, a platform combining naïve and ER-targeted DOX is constructed for in vivo application. Conventional polymer-DOX conjugate inhibits tumor growth by exerting a direct killing effect, and ER-targeted polymer-DOX conjugate suppresses residual tumors by eliciting ICD-associated immunity, together resulting in considerable tumor regression. In addition, simultaneous inhibition of adaptive PD-L1 enrichment (due to negative-feedback to ICD induction) further leads to greater therapeutic outcome. Collectively, ER-targeted therapy can enhance anticancer efficacy by promoting ICD-associated immunotherapy, and potentiating chemotherapy and checkpoint blockade therapy.

Residual cancer burden after neoadjuvant chemotherapy and long-term survival outcomes in breast cancer: a multicentre pooled analysis of 5161 patients

BACKGROUND

Previous studies have independently validated the prognostic relevance of residual cancer burden (RCB) after neoadjuvant chemotherapy. We used results from several independent cohorts in a pooled patient-level analysis to evaluate the relationship of RCB with long-term prognosis across different phenotypic subtypes of breast cancer, to assess generalisability in a broad range of practice settings.

METHODS

In this pooled analysis, 12 institutes and trials in Europe and the USA were identified by personal communications with site investigators. We obtained participant-level RCB results, and data on clinical and pathological stage, tumour subtype and grade, and treatment and follow-up in November, 2019, from patients (aged ≥18 years) with primary stage I-III breast cancer treated with neoadjuvant chemotherapy followed by surgery. We assessed the association between the continuous RCB score and the primary study outcome, event-free survival, using mixed-effects Cox models with the incorporation of random RCB and cohort effects to account for between-study heterogeneity, and stratification to account for differences in baseline hazard across cancer subtypes defined by hormone receptor status and HER2 status. The association was further evaluated within each breast cancer subtype in multivariable analyses incorporating random RCB and cohort effects and adjustments for age and pretreatment clinical T category, nodal status, and tumour grade. Kaplan-Meier estimates of event-free survival at 3, 5, and 10 years were computed for each RCB class within each subtype.

FINDINGS

We analysed participant-level data from 5161 patients treated with neoadjuvant chemotherapy between Sept 12, 1994, and Feb 11, 2019. Median age was 49 years (IQR 20-80). 1164 event-free survival events occurred during follow-up (median follow-up 56 months [IQR 0-186]). RCB score was prognostic within each breast cancer subtype, with higher RCB score significantly associated with worse event-free survival. The univariable hazard ratio (HR) associated with one unit increase in RCB ranged from 1·55 (95% CI 1·41-1·71) for hormone receptor-positive, HER2-negative patients to 2·16 (1·79-2·61) for the hormone receptor-negative, HER2-positive group (with or without HER2-targeted therapy; p<0·0001 for all subtypes). RCB score remained prognostic for event-free survival in multivariable models adjusted for age, grade, T category, and nodal status at baseline: the adjusted HR ranged from 1·52 (1·36-1·69) in the hormone receptor-positive, HER2-negative group to 2·09 (1·73-2·53) in the hormone receptor-negative, HER2-positive group (p<0·0001 for all subtypes).

INTERPRETATION

RCB score and class were independently prognostic in all subtypes of breast cancer, and generalisable to multiple practice settings. Although variability in hormone receptor subtype definitions and treatment across patients are likely to affect prognostic performance, the association we observed between RCB and a patient's residual risk suggests that prospective evaluation of RCB could be considered to become part of standard pathology reporting after neoadjuvant therapy.

FUNDING

National Cancer Institute at the US National Institutes of Health.

Prognostic value of residual cancer burden and Miller-Payne system after neoadjuvant chemotherapy for breast cancer

BACKGROUND

To verify the feasibility of using the residual cancer burden (RCB) index to stratify prognosis of patients after neoadjuvant chemotherapy (NAC) and to compare RCB with the Miller-Payne system.

METHODS

We retrospectively analyzed clinicopathological data of patients receiving treatment between January 1, 2010 and December 31, 2018. Kaplan-Meier curves were used to compare the survival outcomes and estimate disease-free survival (DFS) and disease-specific survival (DSS). Harrell's concordance index (C-index) was used to evaluate the predictive accuracy of RCB and Miller-Payne system.

RESULTS

A total of 423 female patients with complete data were included in the analysis, with a median follow-up time of 58.5 months (range, 7-126 months); 84 patients experienced recurrence, and 48 experienced breast cancer related death. RCB index and the Miller-Payne system were associated with prognosis in the whole cohort. Patients who achieved RCB-I had similar survival outcomes as those with pathological complete response (pCR, RCB-0). In whole cohort, for the RCB index and the Miller-Payne system, respectively, C-indexes for DFS were 0.73 and 0.64, for DSS were 0.74 and 0.64. The average RCB score was different among three subtypes (F=9.335, P<0.001).

CONCLUSIONS

The RCB index and the Miller-Payne system can stratify survival outcome of patients after NAC, and RCB had a superior prediction accuracy, especially for triple-negative breast cancer (TNBC). New cut-off value should be sought in order to improve prediction accuracy.

Neoadjuvant hormonal therapy before radical prostatectomy in high-risk prostate cancer

Patients with high-risk prostate cancer treated with curative intent are at an increased risk of biochemical recurrence, metastatic progression and cancer-related death compared with patients treated for low-risk or intermediate-risk disease. Thus, these patients often need multimodal therapy to achieve complete disease control. Over the past two decades, multiple studies on the use of neoadjuvant treatment have been performed using conventional androgen deprivation therapy, which comprises luteinizing hormone-releasing hormone agonists or antagonists and/or first-line anti-androgens. However, despite results from these studies demonstrating a reduction in positive surgical margins and tumour volume, no benefit has been observed in hard oncological end points, such as cancer-related death. The introduction of potent androgen receptor signalling inhibitors (ARSIs), such as abiraterone, apalutamide, enzalutamide and darolutamide, has led to a renewed interest in using neoadjuvant hormonal treatment in high-risk prostate cancer. The addition of ARSIs to androgen deprivation therapy has demonstrated substantial survival benefits in the metastatic castration-resistant, non-metastatic castration-resistant and metastatic hormone-sensitive settings. Intuitively, a similar survival effect can be expected when applying ARSIs as a neoadjuvant strategy in high-risk prostate cancer. Most studies on neoadjuvant ARSIs use a pathological end point as a surrogate for long-term oncological outcome. However, no consensus yet exists regarding the ideal definition of pathological response following neoadjuvant hormonal therapy and pathologists might encounter difficulties in determining pathological response in hormonally treated prostate specimens. The neoadjuvant setting also provides opportunities to gain insight into resistance mechanisms against neoadjuvant hormonal therapy and, consequently, to guide personalized therapy.

Interobserver variability in the assessment of stromal tumor-infiltrating lymphocytes (sTILs) in triple-negative invasive breast carcinoma influences the association with pathological complete response: the IVITA study

High stromal tumor-infiltrating lymphocytes (sTILs) in triple-negative breast cancer (TNBC) are associated with pathological complete response (pCR) after neoadjuvant chemotherapy (NAC). Histopathological assessment of sTILs in TNBC biopsies is characterized by substantial interobserver variability, but it is unknown whether this affects its association with pCR. Here, we aimed to investigate the degree of interobserver variability in an international study, and its impact on the relationship between sTILs and pCR. Forty pathologists assessed sTILs as a percentage in digitalized biopsy slides, originating from 41 TNBC patients who were treated with NAC followed by surgery. Pathological response was quantified by the MD Anderson Residual Cancer Burden (RCB) score. Intraclass correlation coefficients (ICCs) were calculated per pathologist duo and Bland-Altman plots were constructed. The relation between sTILs and pCR or RCB class was investigated. The ICCs ranged from -0.376 to 0.947 (mean: 0.659), indicating substantial interobserver variability. Nevertheless, high sTILs scores were significantly associated with pCR for 36 participants (90%), and with RCB class for eight participants (20%). Post hoc sTILs cutoffs at 20% and 40% resulted in variable associations with pCR. The sTILs in TNBC with RCB-II and RCB-III were intermediate to those of RCB-0 and RCB-I, with lowest sTILs observed in RCB-I. However, the limited number of RCB-I cases precludes any definite conclusions due to lack of power, and this observation therefore requires further investigation. In conclusion, sTILs are a robust marker for pCR at the group level. However, if sTILs are to be used to guide the NAC scheme for individual patients, the observed interobserver variability might substantially affect the chance of obtaining a pCR. Future studies should determine the 'ideal' sTILs threshold, and attempt to fine-tune the patient selection for sTILs-based de-escalation of NAC regimens. At present, there is insufficient evidence for robust and reproducible sTILs-guided therapeutic decisions.

Assessment of Residual Cancer Burden and Event-Free Survival in Neoadjuvant Treatment for High-risk Breast Cancer: An Analysis of Data From the I-SPY2 Randomized Clinical Trial

Importance

Residual cancer burden (RCB) distributions may improve the interpretation of efficacy in neoadjuvant breast cancer trials.

Objective

To compare RCB distributions between randomized control and investigational treatments within subtypes of breast cancer and explore the relationship with survival.

Design, Setting, and Participants

The I-SPY2 is a multicenter, platform adaptive, randomized clinical trial in the US that compares, by subtype, investigational agents in combination with chemotherapy vs chemotherapy alone in adult women with stage 2/3 breast cancer at high risk of early recurrence. Investigational treatments graduated in a prespecified subtype if there was 85% or greater predicted probability of higher rate of pathologic complete response (pCR) in a confirmatory, 300-patient, 1:1 randomized, neoadjuvant trial in that subtype. Evaluation of a secondary end point was reported from the 10 investigational agents tested in the I-SPY2 trial from March 200 through 2016, and analyzed as of September 9, 2020. The analysis plan included modeling of RCB within subtypes defined by hormone receptor (HR) and ERBB2 status and compared control treatments with investigational treatments that graduated and those that did not graduate.

Interventions

Neoadjuvant paclitaxel plus/minus 1 of several investigational agents for 12 weeks, then 12 weeks of cyclophosphamide/doxorubicin chemotherapy followed by surgery.

Main Outcomes and Measures

Residual cancer burden (pathological measure of residual disease) and event-free survival (EFS).

Results

A total of 938 women (mean [SD] age, 49 [11] years; 66 [7%] Asian, 103 [11%] Black, and 750 [80%] White individuals) from the first 10 investigational agents were included, with a median follow-up of 52 months (IQR, 29 months). Event-free survival worsened significantly per unit of RCB in every subtype of breast cancer (HR-positive/ERBB2-negative: hazard ratio [HZR], 1.75; 95% CI, 1.45-2.16; HR-positive/ERBB2-positive: HZR, 1.55; 95% CI, 1.18-2.05; HR-negative/ERBB2-positive: HZR, 2.39; 95% CI, 1.64-3.49; HR-negative/ERBB2-negative: HZR, 1.99; 95% CI, 1.71-2.31). Prognostic information from RCB was similar from treatments that graduated (HZR, 2.00; 95% CI, 1.57-2.55; 254 [27%]), did not graduate (HZR, 1.87; 95% CI, 1.61-2.17; 486 [52%]), or were control (HZR, 1.79; 95% CI, 1.42-2.26; 198 [21%]). Investigational treatments significantly lowered RCB in HR-negative/ERBB2-negative (graduated and nongraduated treatments) and ERBB2-positive subtypes (graduated treatments), with improved EFS (HZR, 0.61; 95% CI, 0.41-0.93) in the exploratory analysis.

Conclusions and Relevance

In this randomized clinical trial, the prognostic significance of RCB was consistent regardless of subtype and treatment. Effective neoadjuvant treatments shifted the distribution of RCB in addition to increasing pCR rate and appeared to improve EFS. Using a standardized quantitative method to measure response advances the interpretation of efficacy.

Trial Registration

ClinicalTrials.gov Identifier: NCT01042379.

Pre-treatment MRI tumor features and post-treatment mammographic findings: may they contribute to refining the prediction of pathologic complete response in post-neoadjuvant breast cancer patients with radiologic complete response on MRI?

PURPOSE

Radiologic complete response (rCR) in breast cancer patients after neoadjuvant chemotherapy (NAC) does not necessarily correlate with pathologic complete response (pCR), a marker traditionally associated with better outcomes. We sought to verify if data extracted from two important steps of the imaging workup (tumor features at pre-treatment MRI and post-treatment mammographic findings) might assist in refining the prediction of pCR in post-NAC patients showing rCR.

METHODS

A total of 115 post-NAC women with rCR on MRI (2010-2016) were retrospectively assessed. Pre-treatment MRI (lesion morphology, size, and distribution) and post-treatment mammographic findings (calcification, asymmetry, mass, architectural distortion) were assessed, as well as clinical and molecular variables. Bivariate and multivariate analyses evaluated correlation between such variables and pCR. Post-NAC mammographic findings and their correlation with ductal in situ carcinoma (DCIS) were evaluated using Pearson's correlation.

RESULTS

Tumor distribution at pre-treatment MRI was the only significant predictive imaging feature on multivariate analysis, with multicentric lesions having lower odds of pCR (p = 0.035). There was no significant association between tumor size and morphology with pCR. Mammographic residual calcifications were associated with DCIS (p = 0.009). The receptor subtype remained as a significant predictor, with HR-HER2 + and triple-negative status demonstrating higher odds of pCR on multivariate analyses.

CONCLUSIONS

Multicentric lesions on pre-NAC MRI were associated with a lower chance of pCR in post-NAC rCR patients. The receptor subtype remained a reliable predictor of pCR. Residual mammographic calcifications correlated with higher odds of malignancy, making the correlation between mammography and MRI essential for surgical planning. Key Points • The presence of a multicentric lesion on pre-NAC MRI, even though the patient reaches a radiologic complete response on MRI, is associated with a lower chance of pCR. • Molecular status of the tumor remained the only significant predictor of pathologic complete response in such patients in the present study. • Post-neoadjuvant residual calcifications found on mammography were related to higher odds of residual malignancy, making the correlation between mammography and MRI essential for surgical planning.

HER2 Testing Characteristics Can Predict Residual Cancer Burden following Neoadjuvant Chemotherapy in HER2-Positive Breast Cancer

Objectives

The response to HER2-targeted neoadjuvant chemotherapy (NAC) in HER2-positive (+) breast cancer can be quantified using residual cancer burden (RCB) pathologic evaluation to predict relapse free/overall survival. However, more information is needed to characterize the relationship between patterns of HER2 testing results and response to NAC. We evaluated clinicopathologic characteristics associated with RCB categories in HER2+ patients who underwent HER2-directed NAC.

Methods

A retrospective chart review was conducted with Stage I-III HER2+ breast cancer cases following NAC and surgical resection. HER2 immunohistochemistry (IHC) staining and fluorescence in situ hybridization (FISH), histologic/clinical characteristics, hormone receptor status, and RCB scores (RCB-0, RCB-I, RCB-II, and RCB-III) were evaluated.

Results

64/151 (42.4%) patients with HER2+ disease had pathologic complete response (pCR). Tumors with suboptimal response (RCB-II and RCB-III) were more likely to demonstrate less than 100% HER2 IHC 3+ staining (p < 0.0001), lower HER2 FISH copies (p < 0.0001), and lower HER2/CEP17 ratios (p = 0.0015) compared to RCB-I and RCB-II responses. Estrogen receptor classification using ≥10% versus ≥1% staining showed greater association with higher RCB categories.

Conclusions

HER2+ characteristics show differing response to therapy despite all being categorized as positive; tumors with less than 100% IHC 3+ staining, lower HER2 FISH copies, and lower HER2/CEP17 ratios resulted in higher RCB scores.

Neoadjuvant approach as a platform for treatment personalization: focus on HER2-positive and triple-negative breast cancer

The neoadjuvant setting provides unquestionable clinical benefits for high-risk breast cancer (BC) patients, mainly in terms of expansion of locoregional treatment options and prognostic stratification. Additionally, it is also emerging as a strategical tool in the research field. In the present review, by focusing on HER2-positive and triple-negative subtypes, we examined the role of the neoadjuvant setting as a research platform to facilitate and rationalize the placement of escalation strategies, promote the adoption of biomarker-driven approaches for the investigation of de-escalated treatments, and foster the conduction of comprehensive translational analyses, thus ultimately aiming at pursuing treatment personalization. The solid prognostic role of pathologic complete response after neoadjuvant therapy, and its use as a surrogate endpoint to accelerate the drug approval process were discussed. In this context, available data on escalated treatment strategies capable of enhancing pathologic complete response (pCR) rate or improving prognosis of patients with residual disease (RD) after neoadjuvant treatment, were comprehensively reviewed. We also summarized evidence regarding the possibility of obtaining pCR with de-escalated strategies, with particular emphasis on the role of biomarker-driven approaches for patient selection. Pitfalls of the dichotomy of pCR/RD were also deepened, and data on alternative/complementary biomarkers with a possible clinical relevance in this regard were reviewed.

Overcoming the limitations of patch-based learning to detect cancer in whole slide images

Whole slide images (WSIs) pose unique challenges when training deep learning models. They are very large which makes it necessary to break each image down into smaller patches for analysis, image features have to be extracted at multiple scales in order to capture both detail and context, and extreme class imbalances may exist. Significant progress has been made in the analysis of these images, thanks largely due to the availability of public annotated datasets. We postulate, however, that even if a method scores well on a challenge task, this success may not translate to good performance in a more clinically relevant workflow. Many datasets consist of image patches which may suffer from data curation bias; other datasets are only labelled at the whole slide level and the lack of annotations across an image may mask erroneous local predictions so long as the final decision is correct. In this paper, we outline the differences between patch or slide-level classification versus methods that need to localize or segment cancer accurately across the whole slide, and we experimentally verify that best practices differ in both cases. We apply a binary cancer detection network on post neoadjuvant therapy breast cancer WSIs to find the tumor bed outlining the extent of cancer, a task which requires sensitivity and precision across the whole slide. We extensively study multiple design choices and their effects on the outcome, including architectures and augmentations. We propose a negative data sampling strategy, which drastically reduces the false positive rate (25% of false positives versus 62.5%) and improves each metric pertinent to our problem, with a 53% reduction in the error of tumor extent. Our results indicate classification performances of image patches versus WSIs are inversely related when the same negative data sampling strategy is used. Specifically, injection of negatives into training data for image patch classification degrades the performance, whereas the performance is improved for slide and pixel-level WSI classification tasks. Furthermore, we find applying extensive augmentations helps more in WSI-based tasks compared to patch-level image classification.

TIM3 expression on TILs is associated with poor response to neoadjuvant chemotherapy in patients with locally advanced triple-negative breast cancer

Background

The expression of immune checkpoint receptors (ICRs) on tumor-infiltrating lymphocytes (TILs) is associated with better response to immunotherapies via immune checkpoint inhibitors. Therefore, we investigated various ICR expressions on TILs in patients with locally advanced triple-negative breast cancer (TNBC) after neoadjuvant chemotherapy (NAC).

Methods

Expressions of ICRs were examined immunohistochemically in surgical specimens (n = 61) using monoclonal antibodies for PDL-1, PD-1, TIM-3, LAG-3, and CTLA-4. Positivity was defined as staining > 1% on TILs.

Results

The median age was 49 (24–76) years. The majority of patients were clinically T3–4 (n = 31, 50.8%) and clinically N1–3 (n = 58, 95.1%) before NAC. Of those, 82% were found to have CTLA-4 positivity, whereas PD1, PDL-1, LAG3, and TIM-3 expressions on TILs were 62.3, 50.9, 26.2, and 68.9%. A high expression of CTLA-4 was found to be associated with a better chemotherapy response (OR = 7.94, 95% CI: 0.9–70.12, p = 0.06), whereas TIM-3 positivity was contrarily associated with a worse chemotherapy response (OR = 0.253, 95% CI: 0.066–0.974, p = 0.047) as measured by the MDACC Residual Cancer Burden Index. At a 47-month follow-up, ypN0 (DFS; HR = 0.31, 95% CI: 0.12–0.83, p = 0.02 and DSS; HR = 0.21, 95% CI: 0.07–0.62, p = 0.005) and CTLA-4 high expression on TILs (DFS; HR = 0.38, 95% CI: 0.17–0.85, p = 0.019 and DSS; HR = 0.34, 95% CI: 0.15–0.78, p = 0.01) were found to be associated with improved survival.

Conclusions

These findings demonstrate that CTLA-4, PD-1, PDL-1, and TIM-3 were highly expressed in TNBC. Based on these high expression patterns, further studies directed towards combined therapies are warranted in advanced TNBC in future.

Alterations in Breast Cancer Biomarkers Following Neoadjuvant Therapy

INTRODUCTION

Biomarker changes in patients with residual disease (RD) after neoadjuvant systemic therapy (NAT) have unclear consequences. This study examined the prevalence of biomarker [hormone receptor (HR) and HER2] change and its effect on disease-free survival (DFS) and overall survival (OS).

PATIENTS AND METHODS

A total of 303 patients treated with NAT from 2008 to 2016 were identified from a prospective database. Biomarker status at diagnosis was determined and retested after NAT in patients with RD. DFS and OS were compared among three groups: no biomarker change, clinically insignificant change in either ER or PR without alteration in HR status, and clinically significant change in at least one biomarker with resultant change in HR or HER2 status. Subgroups with no change and HR change were examined [HR+HER2- no change, triple negative (TN) no change, HR+HER2- to TN, TN to HR+HER2].

RESULTS

Overall, 61.4% of patients had RD. Of these, 32.8% had changes in at least one biomarker. At median follow up of 5.48 years, no biomarker change was associated with improved DFS compared with changes in HR or HER2 status (p = 0.043). In addition, no biomarker change (p = 0.005) and clinically insignificant changes in biomarker status (p = 0.019) were associated with improved OS compared with clinically significant changes in HR or HER2 status. Among subgroups, HR+HER2- to TN was associated with worse DFS (p = 0.029) and OS (p = 0.008) compared with HR+HER2- no change.

CONCLUSIONS

Among those with RD, biomarker status change was common and impacted survival in subgroups of HR+ or TN disease. Retesting biomarkers after NAT has prognostic implications.

Determination of breast cancer prognosis after neoadjuvant chemotherapy: comparison of Residual Cancer Burden (RCB) and Neo-Bioscore

Background

To compare RCB (Residual Cancer Burden) and Neo-Bioscore in terms of prognostic performance and see if adding pathological variables improve these scores.

Methods

We analysed 750 female patients with invasive breast cancer (BC) treated with neoadjuvant chemotherapy (NAC) at Institut Curie between 2002 and 2012. Scores were compared in global population and by BC subtype using Akaike information criterion (AIC), C-Index (concordance index), calibration curves and after adding lymphovascular invasion (LVI) and pre-/post-NAC TILs levels.

Results

RCB and Neo-Bioscore were significantly associated to disease-free and overall survival in global population and for triple-negative BC. RCB had the lowest AICs in every BC subtype, corresponding to a better prognostic performance. In global population, C-Index values were poor for RCB (0.66; CI [0.61–0.71]) and fair for Neo-Bioscore (0.70; CI [0.65–0.75]). Scores were well calibrated in global population, but RCB yielded better prognostic performances in each BC subtype. Concordance between the two scores was poor. Adding LVI and TILs improved the performance of both scores.

Conclusions

Although RCB and Neo-Bioscore had similar prognostic performances, RCB showed better performance in BC subtypes, especially in luminal and TNBC. By generating fewer prognostic categories, RCB enables an easier use in everyday clinical practice.

Histopathological features of complete pathological response predict recurrence-free survival following neoadjuvant targeted therapy for metastatic melanoma

BACKGROUND

Recent clinical trials demonstrated the safety and efficacy of neoadjuvant dabrafenib and trametinib (DT) among patients with surgically resectable clinical stage III BRAFV600E/K mutant melanoma. Although patients achieving a complete pathological response (pCR) exhibited superior recurrence-free survival (RFS) versus those who did not, 30% of pCR patients relapsed. We sought to identify whether histopathological features of the pathological response further delineated risk of relapse.

METHODS

Surgical resection specimens from DT-treated patients in two phase 2 clinical trials were reviewed. Histopathological features, including relative amounts of viable tumour, necrosis, melanosis, and fibrosis (hyalinized or immature/proliferative) were assessed for associations with patient outcomes.

RESULTS

Fifty-nine patients underwent surgical resection following neoadjuvant DT. Patients achieving pCR (49%) had longer RFS compared with patients who did not (P = 0.005). Patients whose treated tumour showed any hyalinized fibrosis had longer RFS versus those without (P = 0.014), whereas necrosis (P = 0.012) and/or immature/proliferative fibrosis (P = 0.026) correlated with shorter RFS. Multivariable analyses showed absence of pCR or presence of immature fibrosis independently predicted shorter RFS. Among pCR patients, mature/hyalinized-type fibrosis correlated with improved RFS (P = 0.035).

CONCLUSIONS

The extent and composition of the pathological response following neoadjuvant DT in BRAFV600E/K mutant melanoma correlates with RFS, including pCR patients. These findings support the need for detailed histological analysis of specimens collected after neoadjuvant therapy.

Lack of Standardization in the Processing and Reporting of Post-Neoadjuvant Breast Cancer Specimens

CONTEXT.—

The use of neoadjuvant therapy in the management of early-stage invasive breast cancer is increasing. Residual Cancer Burden and other similar tools use pathologic characteristics of post-neoadjuvant therapy breast tumors to determine long-term outcome. However, there are no standardized guidelines for the pathologic evaluation of these specimens in the routine clinical setting.

OBJECTIVE.—

To assess current practices among Canadian pathologists and pathology assistants with regard to the processing and reporting of post-neoadjuvant therapy breast specimens.

DESIGN.—

An electronic survey was distributed to pathologists and pathology assistants across Canada.

RESULTS.—

Sixty-three responses were obtained. A total of 48% (15 of 31) of surveyed pathologists reported familiarity with the Residual Cancer Burden tool. A total of 40% (25 of 63) of respondents reported a lack of routine use of specimen photography, and 35% (22 of 63) reported a lack of routine use of grossing diagrams. There was significant variation with respect to tumor bed sampling; the most common method was to submit 1 block per centimeter of tumor (20 of 63; 32%). There was also significant variation in the method of measuring residual tumor; the most common method was to measure the largest cross-section of residual tumor (16 of 32; 50%).

CONCLUSIONS.—

There is a need for standardization of the evaluation of post-neoadjuvant therapy breast specimens in the routine clinical setting in Canada. We recommend the routine use of specimen mapping, submitting the largest cross section of tumor bed in toto, reporting tumor size as per American Joint Committee on Cancer and Residual Cancer Burden guidelines, and routinely including measurements of residual tumor cellularity and in situ disease in the final pathology report as per Residual Cancer Burden guidelines.

Sociodemographic, Clinical, and Pathological Factors Influencing Outcomes in Locally Advanced Triple Negative Breast Cancer: A Brazilian Cohort

Objective:

To evaluate the association of sociodemographic, clinical, and pathological factors with response and survival in triple negative breast cancer (TNBC) undergoing neoadjuvant chemotherapy (NACT).

Methods:

Clinical-pathological and sociodemographic data were obtained from medical records of 235 eligible women with TNBC diagnosed between 2010 and 2014 undergoing NACT and surgery at the Brazilian National Cancer Institute. They have been assessed for pathological complete response (pCR), event-free survival (EFS), and overall survival (OS). Both univariate and multivariate Cox regression analyses were performed.

Results:

The median follow-up was 64.3 months. Most patients had advanced clinical stage (III: 85.1%; cT3/T4: 86.4%; cN1-3: 74.4%) and high-grade tumors (72.1%). Clinical staging (III vs II, adjusted hazard ratio [HR] = 2.95, P = .012) significantly influenced the pCR rate. Alcohol intake negatively influenced EFS (adjusted HR = 1.67, P = .006) and OS (adjusted HR = 1.89, P = .005). Women with pCR showed better EFS (crude HR = 0.15, P < .001) and OS (crude HR = 0.12, P < .001) compared with non-pCR. The ypT (<0.001) and ypN (<0.001) gradually influenced survival outcomes.

Conclusion:

Clinical stage III were associated with lower response rate and worse survival. Alcohol intake, pCR, and burden of post-NACT residual disease have shown considerable influence on survival outcomes.

[Evaluation of pathological response to neoadjuvant chemotherapy in breast cancer: correlation with molecular phenotype]

INTRODUCTION AND OBJECTIVE

Breast cancer can be classified into different molecular subtypes with important therapeutic and prognostic implications. Neoadjuvant chemotherapy (NAC) increases the possibility of performing conservative surgery and allows in vivo testing of the sensitivity of the tumor. Our aim was to evaluate the pathological response to NAC in relation to the molecular phenotype and the different definitions of the pathological response.

PATIENTS

228 patients treated with NAC and subsequent surgery between 2012 and 2018 were selected from our breast cancer database. Molecular phenotypes were established based on the criteria of the St Gallen 2013 Conference. Pathological response was evaluated following Miller-Payne (breast) and Sataloff (axilla) classification systems.

RESULTS

The most frequent molecular phenotype was luminal B/HER2 negative (30.3%), followed by luminal B/HER2 positive (26.3%), triple negative (24.6%), HER2 positive (13.2%), and luminal A (5.7%). The rate of pathological complete response (pCR) was 35.5% in breast and 15.3% in axilla. The rate of pCR considering breast and axilla together was 26.8%. The molecular phenotype with the highest rate of pCR was HER2 positive (66.7%) followed by triple negative (30.4%), luminal B/HER2 positive (21.7%), luminal B/HER2 negative (14.5%), and luminal A (7.7%) (p < 0.001). The same results were found with the different definitions of pCR we evaluated.

CONCLUSIONS

Complete pathological response to NAC in breast cancer depends largely on the molecular phenotype of the tumor, regardless of the definition of pCR, with the highest response rates in the breast and axilla in the HER2 positive and triple negative phenotypes.

Prognostic value of the Residual Cancer Burden index according to breast cancer subtype: Validation on a cohort of BC patients treated by neoadjuvant chemotherapy

Introduction

The Residual Cancer Burden (RCB) quantifies residual disease after neoadjuvant chemotherapy (NAC). Its predictive value has not been validated on large cohorts with long-term follow up. The objective of this work is to independently evaluate the prognostic value of the RCB index depending on BC subtypes (Luminal, HER2-positive and triple negative (TNBCs)).

Methods

We retrospectively evaluated the RCB index on surgical specimens from a cohort of T1-T3NxM0 BC patients treated with NAC between 2002 and 2012. We analyzed the association between RCB index and relapse-free survival (RFS), overall survival (OS) among the global population, after stratification by BC subtypes.

Results

717 patients were included (luminal BC (n = 222, 31%), TNBC (n = 319, 44.5%), HER2-positive (n = 176, 24.5%)). After a median follow-up of 99.9 months, RCB index was significantly associated with RFS. The RCB-0 patients displayed similar prognosis when compared to the RCB-I group, while patients from the RCB-II and RCB-III classes were at increased risk of relapse (RCB-II versus RCB-0: HR = 3.25 CI [2.1–5.1] p<0.001; RCB-III versus RCB-0: HR = 5.6 CI [3.5–8.9] p<0.001). The prognostic impact of RCB index was significant for TNBC and HER2-positive cancers; but not for luminal cancers (P_interaction = 0.07). The prognosis of RCB-III patients was poor (8-years RFS: 52.7%, 95% CI [44.8–62.0]) particularly in the TNBC subgroup, where the median RFS was 12.7 months.

Conclusion

RCB index is a reliable prognostic score. RCB accurately identifies patients at a high risk of recurrence (RCB-III) with TNBC or HER2-positive BC who must be offered second-line adjuvant therapies.

Immune phenotype of tumor microenvironment predicts response to bevacizumab in neoadjuvant treatment of ER-positive breast cancer

Antiangiogenic drugs are potentially a useful supplement to neoadjuvant chemotherapy for a subgroup of patients with human epidermal growth factor receptor 2 (HER2) negative breast cancer, but reliable biomarkers for improved response are lacking. Here, we report on a randomized phase II clinical trial to study the added effect of bevacizumab in neoadjuvant chemotherapy with FEC100 (5-fluorouracil, epirubicin and cyclophosphamide) and taxanes (n = 132 patients). Gene expression from the tumors was obtained before neoadjuvant treatment, and treatment response was evaluated by residual cancer burden (RCB) at time of surgery. Bevacizumab increased the proportion of complete responders (RCB class 0) from 5% to 20% among patients with estrogen receptor (ER) positive tumors (P = .02). Treatment with bevacizumab was associated with improved 8-year disease-free survival (P = .03) among the good responders (RCB class 0 or I). Patients treated with paclitaxel (n = 45) responded better than those treated with docetaxel (n = 21; P = .03). Improved treatment response was associated with higher proliferation rate and an immune phenotype characterized by high presence of classically activated M1 macrophages, activated NK cells and memory activated CD4 T cells. Treatment with bevacizumab increased the number of adverse events, including hemorrhage, hypertension, infection and febrile neutropenia, but despite this, the ECOG status was not affected.

Pathologic evaluation of response to neoadjuvant therapy drives treatment changes and improves long-term outcomes for breast cancer patients

Systemic therapy for breast cancer may be given before (neoadjuvant) or after (adjuvant) surgery. When neoadjuvant systemic therapy is given, response to treatment can be evaluated. However, some prognostic information (for example, pathologic tumor size pretreatment) is then lost and pathologic evaluation of breast specimens after neoadjuvant therapy is more difficult. Pathologic complete response (pCR), defined as no invasive disease in the breast (ypT0/is or ypT0) and no disease in all sampled lymph nodes (ypN0), identifies patients with a lower risk of recurrence or death compared to those with residual disease. Multidisciplinary collaboration, marking of the tumor site and any lymph node involvement pretreatment, and access to specimen imaging to facilitate correlation of gross and microscopic findings are critical for accurate determination of pCR. For HER2-positive and triple negative tumors requiring systemic therapy, giving the treatment before surgery identifies a high-risk group of patients that can receive additional adjuvant therapy after surgery if a pCR is not achieved. Recent clinical trials have demonstrated that this approach reduced recurrence risk. More than ever, pathologic evaluation of response to neoadjuvant systemic therapy directs treatment received after surgery. Using a single standardized protocol for sampling of the post-neoadjuvant surgical specimen allows pathologists to ensure accurate determination of pCR or residual disease and quantify residual disease. Residual cancer burden (RCB) and AJCC stage provide complementary quantitative information about residual disease and prognosis.

A high mitotic score in breast cancer after neoadjuvant chemotherapy is predictive of outcome and associated with a distinct morphology

AIMS

Neoadjuvant chemotherapy (NAC) is frequently used for the treatment of breast cancer. We sought to analyse the clinical, morphological and immunohistochemical features of tumours from patients who did not achieve pathological complete response following NAC.

METHODS AND RESULTS

We identified stage I-III post-NAC breast cancers from surgical resections (2000-2016) with evaluable residual invasive carcinoma [ypT1a(m) or greater and ≥15% tumour cellularity]. One hundred and forty-three tumours from 142 patients were included. On univariable analysis, a high (score 3) post-NAC mitotic score (as compared with 1 or 2) was significantly associated with invasive ductal carcinoma (IDC) subtype (P = 0.023), high grade, pushing borders with zones of necrosis, hormone receptor and triple-negative status, lack of hormonal therapy, higher cellularity (P < 0.001), and a higher percentage of tumour-infiltrating lymphocytes (P = 0.016). Multivariable analysis showed a high post-NAC mitotic score to be significantly associated with recurrence, distant metastasis, and shortened survival (hazard ratios of 5.73, 4.49, and 3.68, respectively). High post-NAC mitotic score tumours (n = 32) were IDC and had a high Ki67 proliferation index (median, 55%). Of these, 24 (75%) had pushing borders with zones of necrosis; 19 (79.2%) of these had necrosis on preoperative imaging, and 24 (75%), 15 (46.9%) and four (12.5%) lacked androgen receptor, GATA-3 and cytokeratin 18 expression, respectively.

CONCLUSIONS

High post-NAC mitotic score breast cancers cause high morbidity and mortality, frequently have pushing borders and zones of necrosis, and may show loss of common 'breast cancer markers'. Our findings support that necrosis in pretreatment studies and post-NAC mitotic score should be routinely reported, as they offer significant additional prognostic information to guide management.

IASLC Multidisciplinary Recommendations for Pathologic Assessment of Lung Cancer Resection Specimens After Neoadjuvant Therapy

Currently, there is no established guidance on how to process and evaluate resected lung cancer specimens after neoadjuvant therapy in the setting of clinical trials and clinical practice. There is also a lack of precise definitions on the degree of pathologic response, including major pathologic response or complete pathologic response. For other cancers such as osteosarcoma and colorectal, breast, and esophageal carcinomas, there have been multiple studies investigating pathologic assessment of the effects of neoadjuvant therapy, including some detailed recommendations on how to handle these specimens. A comprehensive mapping approach to gross and histologic processing of osteosarcomas after induction therapy has been used for over 40 years. The purpose of this article is to outline detailed recommendations on how to process lung cancer resection specimens and to define pathologic response, including major pathologic response or complete pathologic response after neoadjuvant therapy. A standardized approach is recommended to assess the percentages of (1) viable tumor, (2) necrosis, and (3) stroma (including inflammation and fibrosis) with a total adding up to 100%. This is recommended for all systemic therapies, including chemotherapy, chemoradiation, molecular-targeted therapy, immunotherapy, or any future novel therapies yet to be discovered, whether administered alone or in combination. Specific issues may differ for certain therapies such as immunotherapy, but the grossing process should be similar, and the histologic evaluation should contain these basic elements. Standard pathologic response assessment should allow for comparisons between different therapies and correlations with disease-free survival and overall survival in ongoing and future trials. The International Association for the Study of Lung Cancer has an effort to collect such data from existing and future clinical trials. These recommendations are intended as guidance for clinical trials, although it is hoped they can be viewed as suggestion for good clinical practice outside of clinical trials, to improve consistency of pathologic assessment of treatment response.

Real-time ex vivo perfusion of human lymph nodes invaded by cancer (REPLICANT): a feasibility study

Understanding how breast cancer (BC) grows in axillary lymph nodes (ALNs), and refining how therapies might halt that process, is clinically important. However, modelling the complex ALN microenvironment is difficult, and no human models exist at present. We harvested ALNs from ten BC patients, and perfused them at 37 °C ex vivo for up to 24 h. Controlled autologous testing showed that ALNs remain viable after 24 h of ex vivo perfusion: haematoxylin and eosin-stained histological appearance and proliferation (by Ki67 immunohistochemistry) did not change significantly over time for any perfused ALN compared with a control from time-point zero. Furthermore, targeted gene expression analysis (NanoString PanCancer IO360 panel) showed that only 21/750 genes were differentially expressed between control and perfused ALNs (|log₂ FC| > 1 and q < 0.1): none were involved in apoptosis and metabolism, but rather all 21 genes were involved in immune function and angiogenesis. During perfusion, tissue acid-base balance remained stable. Interestingly, the flow rate increased (p < 0.001) in cancer-replaced (i.e. metastasis occupied more than 90% of the surface area on multiple levels) compared to cancer-free nodes (i.e. nodes with no metastasis on multiple sections). CXCL11 transcripts were significantly more abundant in cancer-replaced nodes, while CXCL12 transcripts were significantly more abundant in cancer-free nodes. These cytokines were also detected in the circulating perfusate. Monoclonal antibodies (nivolumab and trastuzumab) were administered into a further three ALNs to confirm perfusion efficacy. These drugs saturated the nodes; nivolumab even induced cancer cell death. Normothermic ALN perfusion is not only feasible but sustains the tumour microenvironment ex vivo for scientific investigation. This model could facilitate the identification of actionable immuno-oncology targets. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Predictive and Prognostic Roles of Pathological Indicators for Patients with Breast Cancer on Neoadjuvant Chemotherapy

Currently, neoadjuvant chemotherapy is a standard therapeutic strategy for breast cancer, as it can provide timely and individualized chemo-sensitivity information and is beneficial for custom-designing subsequent treatment strategies. To accurately select candidates for neoadjuvant chemotherapy, the association between various immunohistochemical biomarkers of primary disease and tumor response to neoadjuvant chemotherapy has been investigated, and results have shown that certain pathological indicators evaluated after neoadjuvant chemotherapy are associated with long-term prognosis. The Food and Drug Administration (FDA) has recommended that complete pathological response can be used as a surrogate endpoint for neoadjuvant chemotherapy, which is related to better prognosis. Considering that residual tumor persists in the majority of patients after neoadjuvant chemotherapy, the value of various pathological indicators of residual disease in predicting the long-term outcomes is being extensively investigated. This review summarizes and compares various predictive and prognostic indicators for patients who have received neoadjuvant chemotherapy, and analyzes their efficacy in different breast cancer subtypes.

Automated and Manual Quantification of Tumour Cellularity in Digital Slides for Tumour Burden Assessment

The residual cancer burden index is an important quantitative measure used for assessing treatment response following neoadjuvant therapy for breast cancer. It has shown to be predictive of overall survival and is composed of two key metrics: qualitative assessment of lymph nodes and the percentage of invasive or in situ tumour cellularity (TC) in the tumour bed (TB). Currently, TC is assessed through eye-balling of routine histopathology slides estimating the proportion of tumour cells within the TB. With the advances in production of digitized slides and increasing availability of slide scanners in pathology laboratories, there is potential to measure TC using automated algorithms with greater precision and accuracy. We describe two methods for automated TC scoring: 1) a traditional approach to image analysis development whereby we mimic the pathologists’ workflow, and 2) a recent development in artificial intelligence in which features are learned automatically in deep neural networks using image data alone. We show strong agreements between automated and manual analysis of digital slides. Agreements between our trained deep neural networks and experts in this study (0.82) approach the inter-rater agreements between pathologists (0.89). We also reveal properties that are captured when we apply deep neural network to whole slide images, and discuss the potential of using such visualisations to improve upon TC assessment in the future.

q-Space Imaging Yields a Higher Effect Gradient to Assess Cellularity than Conventional Diffusion-weighted Imaging Methods at 3.0 T: A Pilot Study with Freshly Excised Whole-Breast Tumors

Purpose

To determine whether q-space imaging (QSI), an advanced diffusion-weighted MRI method, provides a higher effect gradient to assess tumor cellularity than existing diffusion imaging methods, and fidelity to cellularity obtained from histologic analysis.

Materials and Methods

In this prospective study, diffusion-weighted images were acquired from 20 whole-breast tumors freshly excised from participants (age range, 35-78 years) by using a clinical 3.0-T MRI unit. Median and skewness values were extracted from the histogram distributions obtained from QSI, monoexponential model, diffusion kurtosis imaging (DKI), and stretched exponential model (SEM). The skewness from QSI and other diffusion models was compared by using paired t tests and relative effect gradient obtained from correlating skewness values.

Results

The skewness obtained from QSI (mean, 1.34 ± 0.77 [standard deviation]) was significantly higher than the skewness from monoexponential fitting approach (mean, 1.09 ± 0.67; P = .015), SEM (mean, 1.07 ± 0.70; P = .014), and DKI (mean, 0.97 ± 0.63; P = .004). QSI yielded a higher effect gradient in skewness (percentage increase) compared with monoexponential fitting approach (0.26 of 0.74; 35.1%), SEM (0.26 of 0.74; 35.1%), and DKI (0.37 of 0.63; 58.7%). The skewness and median from QSI were significantly correlated with the skewness (ρ = -0.468; P = .038) and median (ρ = -0.513; P = .021) of cellularity from histologic analysis.

Conclusion

QSI yields a higher effect gradient in assessing breast tumor cellularity than existing diffusion methods, and fidelity to underlying histologic structure.Keywords: Breast, MR-Diffusion Weighted Imaging, MR-Imaging, Pathology, Tissue Characterization, Tumor ResponseOnline supplemental material is available for this article.Published under a CC BY 4.0 license.

Validation of Residual Cancer Burden as Prognostic Factor for Breast Cancer Patients After Neoadjuvant Therapy

Background

Assessing the residual cancer burden (RCB) predictive performance, the potential subgroup effects, and time-dependent impact on breast cancer patients who underwent neoadjuvant therapy in a developer’s independent cohort is essential for its usage in clinical routine.

Methods

Between 2011 and 2016, the RCB scores of 184 female breast cancer patients were prospectively collected, and subsequent clinicopathological and follow-up data were obtained retrospectively. Recurrence-free survival (RFS), overall survival (OS), as well as subgroup analysis, and time-dependent variables were calculated with multivariate, complex, or linear statistical models.

Results

A total of 184 patients (HER2 33%, TNBC 27%), with a mean follow-up time of 4 years, treated with neoadjuvant systemic therapy (92% anthracycline-taxane based) were analyzed revealing 43 events (38 recurrences, 28 deaths). High RCB scores were associated with recurrence (median index: 2.34 vs. 1.39 points, rank-sum p < 0.0001), decreased RFS (hazard ratio [HR] = 1.80, 95% confidence interval [CI] 1.44–2.24, p < 0.0001) and reduced OS (HR 1.96, 95% CI 1.49–2.59, p < 0.0001). The RCB score showed proportionality of hazards (interaction HR with linear follow-up time = 1.00, p = 0.896) and good discriminating power (Harrell’s c index 0.7).

Conclusions

Our results confirm the RCB score as externally valid prognostic marker and being independent of molecular subtype for RFS and OS in a clinical setting.

Electronic supplementary material

The online version of this article (10.1245/s10434-019-07741-w) contains supplementary material, which is available to authorized users.

Landscape of transcriptomic interactions between breast cancer and its microenvironment

Solid tumours comprise mixtures of tumour cells (TCs) and tumour-adjacent cells (TACs), and the intricate interconnections between these diverse populations shape the tumour’s microenvironment. Despite this complexity, clinical genomic profiling is typically performed from bulk samples, without distinguishing TCs from TACs. To better understand TC–TAC interactions, we computationally distinguish their transcriptomes in 1780 primary breast tumours. We show that TC and TAC mRNA abundances are divergently associated with clinical phenotypes, including tumour subtypes and patient survival. These differences reflect distinct responses of TCs and TACs to specific somatic driver mutations, particularly TP53. These data further elucidate how the molecular interplay between breast tumours and their microenvironment drives aggressive tumour phenotypes.

The transcriptomic profile of tumour-adjacent cells provides important information about tumour context but its clinical utility is unclear. Here, in breast cancer, Fox et al. show that the mRNA abundances of tumour and tumour-adjacent cells hold prognostic information.

Breast specimen handling and reporting in the post-neoadjuvant setting: challenges and advances

Neoadjuvant systemic therapy is becoming more commonly used in patients with earlier stages of breast cancer. To assess tumour response to neoadjuvant chemotherapy, pathological evaluation is the gold standard. Depending on the treatment response, the pathological examination of these specimens can be quite challenging. However, a uniform approach to evaluate post-neoadjuvant-treated breast specimens has been lacking. Furthermore, there is no single universally accepted or endorsed classification system for assessing treatment response in this setting. Recent initiatives have attempted to create a standardised protocol for evaluation of post-neoadjuvant breast specimens. This review outlines the necessary information that should be collected prior to macroscopic examination of these specimens, the recommended and most pragmatic approach to tissue sampling for microscopic examination, describes the macroscopic and microscopic features of post-therapy breast specimens, summarises two commonly used systems for classifying treatment response and outlines the critical variables that should be included in the final pathology report.

Outcome for triple negative breast cancer in a retrospective cohort with an emphasis on response to platinum-based neoadjuvant therapy

Purpose

The rate of pathological complete response (pCR) for patients with triple negative breast cancer (TNBC) is increased when carboplatin is added to neo-adjuvant chemotherapy (NACT). However, while phase III trial data showing a survival benefit are awaited, carboplatin is not yet standard-of-care for TNBC. The aim of this study was to examine the rate of pCR and the outcome for those treated with carboplatin and to examine the predictors of response to therapy.

Methods

The retrospective series comprised 333 consecutive patients with TNBC (median follow-up time, 43 months). Adjuvant chemotherapy was given to 51% (n = 168) of patients and 29% (n = 97) received anthracycline–taxane NACT with carboplatin given to 9% (n = 31) of patients.

Results

Overall, 25% (n = 78) of patients experienced a breast cancer recurrence and 22% (n = 68) died from disease. A pCR breast and pCR breast/axilla was more common in those who received carboplatin (n = 18, 58% and n = 17, 55%, respectively) compared those who did not (n = 23, 36% and n = 18, 28%, respectively) (p = 0.041 and p = 0.011, respectively). By multivariable analysis, carboplatin and high tumor grade were independent predictors of pCR breast/axilla (OR_non-pCR = 0.17; 95% CI 0.06–0.54; p = 0.002; and OR_non-pCR = 0.05, 95% CI 0.01–0.27; p < 0.001, respectively). pCR breast/axilla was an independent predictor of DFS (HR_non-pCR=6.23; 95% CI 1.36–28.50; p = 0.018), metastasis-free survival (HR_non-pCR = 5.08; 95% CI 1.09–23.65; p = 0.038) and BCSS (HR_non-pCR = 8.52; 95% CI 1.09–66.64; p = 0.041).

Conclusion

Carboplatin therapy and high tumor grade are associated with a significant increase in the rate of pCR, which is an independent predictor of outcome. These data support the use of carboplatin in NACT for TNBC, while results from phase III studies are awaited.

Electronic supplementary material

The online version of this article (10.1007/s10549-018-5066-6) contains supplementary material, which is available to authorized users.