Characterizing Response to Neoadjuvant Chemotherapy in Invasive Lobular Breast Carcinoma

Co-regulator activity of Mediator of DNA Damage Checkpoint 1 (MDC1) is associated with DNA repair dysfunction and PARP inhibitor sensitivity in lobular carcinoma of the breast

Invasive lobular carcinoma of the breast (ILC) are typically estrogen receptor α (ER)-positive and present with biomarkers of anti-estrogen sensitive disease, yet patients with ILC face uniquely poor long-term outcomes with increased recurrence risk, suggesting endocrine response and ER function are unique in ILC. We previously found specifically in ILC cells that ER is co-regulated by the DNA repair protein Mediator of DNA Damage Checkpoint 1 (MDC1). This novel MDC1 activity, however, was associated with dysfunction in the canonical DNA repair activity of MDC1, but absent typical features of DNA repair deficiency. To understand reciprocal activities of MDC1, we profiled the MDC1 interactome and found MDC1-associated proteins in ILC cells mirror a "BRCA-like" state lacking key homologous recombination (HR) proteins, consistent with HR dysfunction but distinct from classic "BRCAness". HR dysfunction in ILC cells was mirrored in single-cell transcriptome and DNA repair activity analyses, along with DNA repair signaling and functional data, showing dysfunctional HR induction and resolution. In parallel, ILC tumor data are consistent with a distinct form of HR dysfunction via impaired HR resolution, lacking BRCA-like genomic scarring but with elevated signatures of PARP inhibitor sensitivity. We tested whether this HR dysfunction could indeed be exploited using PARP inhibition and found that talazoparib treatment produced a durable growth suppression in vitro and in multiple ILC xenografts in vivo. ILC-specific ER:MDC1 activity creates a new context for ER and MDC1 function in ILC, at the cost of a DNA repair dysfunction that is therapeutically targetable.

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.

Successful Breast Conservation After Neoadjuvant Chemotherapy in Lobular Breast Cancer: The Role of Menopausal Status in Response to Treatment

BACKGROUND

While neoadjuvant chemotherapy (NAC) has been shown to increase rates of breast conservation surgery (BCS) for breast cancer, response rates in invasive lobular carcinoma (ILC) appear lower than other histologic subtypes. Some data suggest higher response rates to NAC in premenopausal versus postmenopausal patients, but this has not been studied in ILC. We evaluated the rates of successful BCS after NAC in patients with ILC stratified by menopausal status.

PATIENTS AND METHODS

We analyzed data from a single-institution cohort of 666 patients with stage I-III hormone receptor positive HER-2 negative ILC. We used t-tests, chi-squared tests, and multivariable logistic regression to investigate rates of NAC use, attempted BCS, and associations between NAC and successful BCS by menopausal status.

RESULTS

In 217 premenopausal and 449 postmenopausal patients, NAC was used more often in the premenopausal group (15.2% vs. 9.8%, respectively, p = 0.041). Among those who attempted breast conservation (51.3% of pre- and 64.8% of postmenopausal cohorts), NAC was not associated with successful BCS in either group. Interestingly, for postmenopausal patients, receipt of NAC was significantly associated with increased rates of completion mastectomy in those who had positive margins at the first attempt at BCS.

CONCLUSION

NAC was not associated with successful BCS in either premenopausal or postmenopausal patients with ILC. Although premenopausal patients were more likely to receive NAC, these data suggest that menopausal status may not be a good predictor of response to chemotherapy. Better predictors of response and more efficacious treatment for patients with ILC are needed.

Change in Main Histological Type of Invasive Breast Cancer From Ductal to Lobular Carcinoma by Neoadjuvant Chemotherapy

We present a case study of breast cancer initially diagnosed as invasive ductal carcinoma (IDC), which subsequently substituted into invasive lobular carcinoma (ILC) following neoadjuvant chemotherapy (NAC). A 61-year-old woman presented with a palpable breast lump, and histological examination through core needle biopsy (CNB) confirmed the presence of IDC. After a 6-month course of NAC, the patient achieved a clinically complete response (cCR) and underwent mastectomy. The surgical specimen showed no detectable tumor upon palpation, but microscopic analysis revealed a highly infiltrative growth of poorly-cohesive small atypical cells in the original tumor area. Immunohistochemical staining demonstrated that the tumor cells were negative for E-cadherin, leading to a diagnosis of ILC. To address the histological discrepancy before and after NAC, we re-evaluated the initial CNB using E-cadherin immunohistochemistry. While most tumor cells were E-cadherin positive, a small area displaying scirrhous subtype-like morphology exhibited E-cadherin negativity. Consequently, we revised the diagnosis to mixed IDC-ILC. The differential chemosensitivity between IDC and ILC may provide insight into this phenomenon.

Clinical outcomes and prognostic factors in triple-negative invasive lobular carcinoma of the breast

PURPOSE

Triple-negative invasive lobular carcinoma (TN-ILC) of breast cancer is a rare disease and the clinical outcomes and prognostic factors are not well-defined.

METHODS

Women with stage I-III TN-ILC or triple-negative invasive ductal carcinoma (TN-IDC) of the breast undergoing mastectomy or breast-conserving surgery between 2010 and 2018 in the National Cancer Database were included. Kaplan-Meier curves and multivariate Cox proportional hazard regression were used to compare overall survival (OS) and evaluate prognostic factors. Multivariate logistic regression was performed to analyze the factors associated with pathological response to neoadjuvant chemotherapy.

RESULTS

The median age at diagnosis for women with TN-ILC was 67 years compared to 58 years in TN-IDC (p < 0.001). There was no significant difference in the OS between TN-ILC and TN-IDC in multivariate analysis (HR 0.96, p = 0.44). Black race and higher TNM stage were associated with worse OS, whereas receipt of chemotherapy or radiation was associated with better OS in TN-ILC. Among women with TN-ILC receiving neoadjuvant chemotherapy, the 5-year OS was 77.3% in women with a complete pathological response (pCR) compared to 39.8% in women without any response. The odds of achieving pCR following neoadjuvant chemotherapy were significantly lower in women with TN-ILC compared to TN-IDC (OR 0.53, p < 0.001).

CONCLUSION

Women with TN-ILC are older at diagnosis but have similar OS compared to TN-IDC after adjusting for tumor and demographic characteristics. Administration of chemotherapy was associated with improved OS in TN-ILC, but women with TN-ILC were less likely to achieve complete response to neoadjuvant therapy compared to TN-IDC.

Observation effectiveness of dose-dense neoadjuvant anthracycline sequential weekly paclitaxel for triple-negative breast cancer patients

INTRODUCTION/BACKGROUND

To investigate the differences in pathological response and survival outcomes between dose-dense and conventional-interval neoadjuvant chemotherapy (NAC) in patients with triple-negative breast cancer (TNBC).

PATIENTS AND METHODS

Patients with TNBC who received NAC including epirubicin plus cyclophosphamide followed by weekly paclitaxel were included. A total of 494 patients were divided into either the dose-dense anthracycline (ddEC-wP) group or conventional interval anthracycline (EC-wP) group.

RESULTS

The breast pathological complete response (bpCR, ypT0/is) rate was 45.3% (n = 101) in the dose-dense group and 34.3% (n = 93) in the conventionally scheduled group, which was a significant difference (P = .013), and in the 251 pN+ cases, the lymph node pathological complete response (LNpCR, ypN0) rate was 57.9% (n = 62) in the dose-dense group and 43.7% (n = 63) in the conventionally scheduled group, which was a significant difference (P = .026) in the univariate analysis. In the multivariate logistic regression analysis, 3 variables were predictive of bpCR: pathological type, surgical methods and type of chemotherapy, with P values of .012, .001 and .021, respectively. Two variables were predictive of LNpCR: type of chemotherapy and Her-2 expression, with P values of .039 and .020, respectively. After a median follow-up of 54 months, there was no significant difference in survival for disease-free survival (DFS) (hazard ratio [HR], 0.788; 95% confidence interval [CI], 0.508 to 1.223; P = .288), distant disease-free survival (DDFS) (HR, 0. 709; 95% CI, 0.440 to 1.144; P = .159) or overall survival (OS) (HR, 0. 750; 95% CI, 0.420 to 1.338; P = .330) between the 2 groups.

CONCLUSION

Our study demonstrated that TNBC achieved a higher bpCR rate and LNpCR rate after dose-dense neoadjuvant chemotherapy than the conventional scheme. The survival benefit of the 2 groups did not reach statistical difference.

Response Rates of Invasive Lobular Cancer in Patients Undergoing Neoadjuvant Endocrine or Chemotherapy

BACKGROUND

A gap remains in the role of neoadjuvant therapy for patients with ILC.

METHOD

Single-institution retrospective review of patients with ILC who received neoadjuvant therapy between 2008 and 2019.

RESULTS

141 patients met inclusion criteria: 71 neoadjuvant chemotherapy (NACT) and 70 neoadjuvant endocrine therapy (NET). 7/71 (9.9%) patients had a pCR following NACT compared to 1/70 (1.4%) with NET (P = .063). pCR was observed in 5/18 (27.8%) patients with Her2Neu-positive disease following NACT, compared to 2/53 (3.8%) with Her2Neu-negative disease (P = .01).For luminal B tumors, median Ki-67 decrease was similar following NACT and NET (18.3 vs 16.3, P = .26).T category decreased in 59 (42.1%) patients following neoadjuvant therapy, increased in 9 (6.4%), and was unchanged in 72 (51.4%). More patients had an increase (28.6%) than decrease (12.1%) in their N category, including 13/60 (21.7%) who were clinically node-negative at diagnosis and identified to have node-positive disease following neoadjuvant therapy, at definitive surgery.

CONCLUSION

In Her2Neu-negative ILC, the potential of a pCR with NACT or NET is low. Most patients' nodal status and tumor size remain unchanged. There is a potential for pathologic stage to be higher at surgery compared to the clinical stage prior to neoadjuvant therapy.

[Associating prognostic factors with clinical results in locally advanced breast cancer]

Background

Breast cancer is the most frequent malignant tumor in women.

Objective

To identify clinico-pathological and molecular markers as predictors of survival in patients with locally advanced breast cancer (LABC).

Methods

Retrospective and observational study. The clinical factors of clinico-pathological and molecular predictors in relation with overall survival (OS) were assessed by the survival function, baseline hazard with smoothing and Cox regression.

Results

126 patients were assessed. OS at five years was significantly superior in patients with clinical stage IIIA (87%; p < 0.001), grade 2 tumor (81%; p < 0.001), pathological node stage (ypN0: 90%; p < .001), low-risk Nottingham prognostic index (86%; p < 0.001) and luminal A subtype (88%; p = 0.022). Baseline hazard with smoothing exhibited an increase in the mortality rate at 50 months for the luminal B/ HER2+ subtype compared with other subtypes. The multivariate analysis ascertained that the stage ypN2-3 (hazard ratio [HR] = 7.3; 95% confidence interval [95% CI]: 2.2 to 23.9) and the HER2+ nonluminal (HR = 7.8; 95% CI: 2 to 29.6) and triple negative (HR = 5.4; 95% CI: 1.7 to 17.2) subtypes were associated with a poor OS.

Conclusions

The comprehensive evaluation of the molecular marker and clinico-pathological factors provides more accurate predictive and prognostic information. The nodal stage and molecular subtype are suitable clinical parameters on survival for LABC patients.

Do non-classic invasive lobular carcinomas derive a benefit from neoadjuvant chemotherapy?

PURPOSE

Invasive lobular breast cancers (ILCs) respond poorly to neoadjuvant chemotherapy (NAC). The degree of benefit of NAC among non-classic ILC (NC-ILC) variants compared with classic ILCs (C-ILCs) is unknown.

METHODS

Consecutive patients with Stage I-III ILC treated from 2003 to 2019 with NAC and surgery were identified, and grouped as C-ILC or NC-ILC as per the original surgical pathology report, with pathologist (A.G.) review performed if original categorization was unclear. A subset of similarly treated invasive ductal cancers (IDCs) was identified for comparison. Clinicopathologic characteristics and pathologic complete response (pCR) rates were evaluated.

RESULTS

Of 145 patients with ILC, 101 (70%) were C-ILC and 44 (30%) were NC-ILC (IDC cohort: 1157 patients). ILC patients were older, more often cT3/T4 and cN2/N3, and less often high-grade compared to IDC patients. Those with NC-ILC were less often ER+/HER2- (55% versus 93%), and more often HER2 + (25% versus 7%) and TN (21% versus 0%, all p < 0.001). Breast pCR was more common among NC-ILC, but most frequent in IDC. Nodal pCR rates were also lowest among C-ILC patients, but similar among NC-ILC and IDC patients. On multivariable analysis, C-ILC (OR 0.09) and LVI (OR 0.51) were predictive of lack of breast pCR; non-ER+/HER2- subtypes and breast pCR were predictive of nodal pCR. When our analysis was repeated with patients stratified by receptor subtype, histology was not independently predictive of either breast or nodal pCR.

CONCLUSION

NC-ILC patients were significantly more likely to achieve breast and nodal pCR compared with C-ILC patients, but when stratified by subtype, histology was not independently predictive of breast or nodal pCR.

Clinical outcomes in patients with triple negative or HER2 positive lobular breast cancer: a single institution experience

PURPOSE

Invasive lobular carcinomas (ILC) are characterised by loss of the cell adhesion molecule E-cadherin. Approximately 15% of ILC are ER negative at the time of breast cancer diagnosis, or at relapse due to loss of ER expression. Less than 5% of classical ILC but up to 35% of pleomorphic ILC are HER2 positive (HER2+).

METHODS

Retrospective analysis of clinic-pathological data from patients with Triple negative (TN) or HER2+ ILC diagnosed 2004-2014 at the Royal Marsden Hospital. The primary endpoint was median overall survival (OS) in patients with metastatic disease. Secondary endpoints included response rate to neo-adjuvant chemotherapy (NAC), median disease-free interval (DFI) and OS for patients with early disease.

RESULTS

Three of 16 patients with early TN ILC and 7/33 with early HER2+ ILC received NAC with pCR rates of 0/3 and 3/5 patients who underwent surgery, respectively. Median DFI was 28.5 months [95% Confidence interval (95%CI) 15-78.8] for TN ILC and not reached (NR) (111.2-NR) for HER2+ early ILC. Five-year OS was 52% (95%CI 23-74%) and 77% (95%CI 58-88%), respectively. Twenty-three patients with advanced TN ILC and 14 patients with advanced HER2+ ILC were identified. Median OS was 18.3 months (95%CI 13.0-32.8 months) and 30.4 months (95%CI 8.8-NR), respectively.

CONCLUSIONS

In our institution we report a high relapse rate after treatment for early TN ILC, but median OS from metastatic disease is similar to that expected from TN IDC. Outcomes for patients with advanced HER2+ ILC were less favourable than those expected for IDC, possibly reflecting incomplete exposure to anti-HER2 therapies.

CLINICAL TRIAL REGISTRATION

ROLo (ClinicalTrials.gov Identifier: NCT03620643), ROSALINE (ClinicalTrials.gov Identifier: NCT04551495).

Differences in sensitivity to neoadjuvant chemotherapy among invasive lobular and ductal carcinoma of the breast and implications on surgery-A systematic review and meta-analysis

Meta-analysis of >87,000 patients demonstrates that patients with invasive lobular carcinoma of the breast are far less likely to achieve pCR of the breast or axilla compared to their ductal counterparts, receive less BCS and more frequently return positive margins.

BACKGROUND

Neoadjuvant chemotherapy (NACT) facilitates tumour downstaging, increases breast conserving surgery (BCS) and assesses tumour chemosensitivity. Despite clinicopathological differences in Invasive Ductal Carcinoma (IDC) and Invasive Lobular Carcinoma (ILC), decision making surrounding the use NACT does not take account of histological differences.

AIM

To determine the impact NACT on pathological complete response (pCR), breast conserving surgery (BCS), margin status and axillary pCR in ILC and IDC.

METHODS

A systematic review was performed in accordance with the PRISMA guidelines. Studies reporting outcomes among ILC and IDCs following NACT were identified. Dichotomous variables were pooled as odds ratios (ORs) with 95% confidence intervals_(CI) using the Mantel-Haenszel method. P-values <0.05 were statistically significant.

RESULTS

40 studies including 87,303 (7596 ILC [8.7%]and 79,708 IDC [91.3%]) patients were available for analysis. Mean age at diagnosis was 54.9 vs. 50.9 years for ILC and IDC, respectively. IDCs were significantly more likely to achieve pCR (22.1% v 7.4%, OR: 3.03 [95% CI 2.5-3.68] p < 0.00001), axillary pCR (23.6% vs. 13.4%, OR: 2.01 [95% CI 1.77-2.28] p < 0.00001) and receive BCS (45.7% vs. 33.3%, OR 2.14 [95% CI 1.87-2.45] p < 0.00001) versus ILCs. ILCs were significantly more likely to have positive margins at the time of surgery (36% vs 13.5%, OR 4.84 [95% CI 2.88-8.15] p < 0.00001).

CONCLUSION

This is the largest study comparing the impact of NACT among ILC and IDC with respect to pCR and BCS. ILC has different outcomes to IDC following NACT and incorporate it into treatment decisions and future clinical guidelines.

Breast cancer resistance to chemotherapy: When should we suspect it and how can we prevent it?

Chemotherapy is an essential treatment for breast cancer, inducing cancer cell death. However, chemoresistance is a problem that limits the effectiveness of chemotherapy. Many factors influence chemoresistance, including drug inactivation, changes in drug targets, overexpression of ABC transporters, epithelial-to-mesenchymal transitions, apoptotic dysregulation, and cancer stem cells. The effectiveness of chemotherapy can be assessed clinically and pathologically. Clinical response evaluation is based on physical examination or imaging (mammography, ultrasonography, computed tomography scan, or magnetic resonance imaging) and includes tumor size changes after chemotherapy. Pathological response evaluation is a method based on tumor residues in histopathological preparations. We should be suspicious of chemoresistance if there are no significant changes clinically according to the Response Evaluation Criteria in Solid Tumors and World Health Organization criteria or pathological changes according to the Miller and Payne criteria, especially after 2–3 cycles of chemotherapy treatments. Chemoresistance is mostly detected after the administration of chemotherapy drugs. No reliable parameters or biomarkers can predict chemotherapy responses appropriately and effectively. Well-known parameters such as cancer type, grade, subtype, estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, Ki-67, and MDR-1/P-gP have been used for selecting chemotherapy regimens. Some new methods for predicting chemoresistance include chemosensitivity and chemoresistance assays, multigene expressions, and positron emission tomography assays. The latest approaches are based on evaluation of molecular processes and the metabolic activity of cancer cells. Some methods for preventing chemoresistance include using the right regimen, using some combination of chemotherapy methods, conducting adequate monitoring, and using drugs that could prevent the emergence of multidrug resistance.

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Chemotherapy is an essential treatment in the management of breast cancer.

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Chemotherapy is carried out based on the selection of regimens for the specific individual and tumor characteristics.

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Combination therapy, monitoring, and evaluation are used to prevent chemoresistance.

Mediator of DNA Damage Checkpoint 1 (MDC1) Is a Novel Estrogen Receptor Coregulator in Invasive Lobular Carcinoma of the Breast

Invasive lobular carcinoma (ILC) is the most common special histologic subtype of breast cancer, and nearly all ILC tumors express estrogen receptor alpha (ER). However, clinical and laboratory data suggest ILC are strongly estrogen-driven but not equally antiestrogen-sensitive. We hypothesized ILC-specific ER coregulators mediate ER functions and antiestrogen resistance in ILC, and profiled ER-associated proteins by mass spectrometry. Three ER+ ILC cell lines (MDA MB 134VI, SUM44PE, and BCK4) were compared with ER+ invasive ductal carcinoma (IDC) line data, and we examined whether siRNA of identified proteins suppressed ER-driven proliferation in ILC cells. This identified mediator of DNA damage checkpoint 1 (MDC1), a tumor suppressor in DNA damage response (DDR), as a novel ER coregulator in ILC. We confirmed ER:MDC1 interaction was specific to ILC versus IDC cells, and found MDC1 knockdown suppressed ILC cell proliferation and tamoxifen resistance. Using RNA-sequencing, we found in ILC cells MDC1 knockdown broadly dysregulates the ER transcriptome, with ER:MDC1 target genes enriched for promoter hormone response elements. Importantly, our data are inconsistent with MDC1 tumor suppressor functions in DDR, but suggest a novel oncogenic role for MDC1 as an ER coregulator. Supporting this, in breast tumor tissue microarrays, MDC1 protein was frequently low or absent in IDC, but MDC1 loss was rare in ER+ ILC. ER:MDC1 interaction and MDC1 coregulator functions may underlie ER function in ILC and serve as targets to overcome antiestrogen resistance in ILC. IMPLICATIONS: MDC1 has novel ER coregulator activity in ILC, which may underlie ILC-specific ER functions, estrogen response, and antiestrogen resistance.

Survival Outcomes in Invasive Lobular Carcinoma Compared to Oestrogen Receptor-Positive Invasive Ductal Carcinoma

Invasive lobular breast cancer (ILC) accounts for 10-15% of breast cancers and has distinct characteristics compared with the more common invasive ductal carcinoma (IDC). Studies have shown that ILC may be less sensitive to chemotherapy than IDC, with lower rates of complete pathological response after neo-adjuvant chemotherapy, but it is not clear how this affects long-term survival. Patients at Guy's and St Thomas' NHS Foundation Trust between 1975 and 2016 diagnosed with ER+ IDC or ER+ ILC were eligible for inclusion. Kaplan-Meier plots and Cox proportional-hazards regression models were used for analysis. There was no difference in overall survival comparing ER+ ILC to ER+ IDC (OR: 0.94, 95% CI: 0.83, 1.04) with a median follow-up time of 8.3 years compared to 8.4 years in IDC. However, ER+HER2- ILC had worse survival compared to ER+HER2- IDC in those that received chemotherapy (OR: 1.46, 95% CI: 1.06, 2.01). Here, median follow-up time was 7.0 years in ILC compared to 8.1 years in IDC. These results indicate worse overall survival after chemotherapy (neo-adjuvant and adjuvant) in ILC compared to ER+HER2- IDC even when correcting for tumour grade, age, size, and nodal involvement, but validation is needed in a larger study population.

The Clinical Relevance of Target Lymph Node Biopsy after Primary Systemic Therapy in Initially Node-Positive Breast Cancer Patients

Simple Summary

Currently, the optimal axillary surgical approach for breast cancer patients with initial node-positive disease and conversion to clinically node-negative status after primary systemic therapy is unclear. The aim of our study was to evaluate the clinical impact of removing the initially most suspicious, labeled axillary lymph node in addition to the sentinel lymph node. Metastatic target lymph nodes were found in five out of 63 patients (7.9%), while the sentinel lymph node was either tumor-free or not detected. The removal of the target lymph node influenced the adjuvant systemic therapy in only one case (1.6%). However, complete axillary dissection was indicated in all five cases. Furthermore, with fewer than three sentinel lymph nodes removed, the target lymph node reduced the false-negative rate to less than 10%. We therefore conclude that although the target lymph node has a minor impact on adjuvant systemic therapy, it is relevant for surgical axillary management.

Abstract

Purpose: To assess the impact of the removal of the target lymph node (TLN) on therapy after the completion of primary systemic therapy (PST) in initially node-positive breast cancer patients. Methods: Pooled data analysis of participants of the prospective CLIP- and TATTOO-study at the University of Rostock was performed. Results: A total of 75 patients were included; 63 of them (84.0%) converted to clinically node-negative after PST. Both TLN and sentinel lymph node (SLN) were identified in 41 patients (51.2%). In five out of 63 patients (7.9%), the TLN was metastatic after PST and the SLN was either tumor-free or not detected. Axillary lymph node dissection (ALND) was conducted in all five patients. In one patient, systemic therapy recommendation was influenced by the TLN; adjuvant radiotherapy was influenced by the TLN in zero patients. For patients with fewer than three removed SLNs, the FNR was 28.6% for the SLN biopsy alone and 7.1% for targeted axillary dissection (TAD). Conclusions: Removal of the TLN in addition to the SLN after PST has only minimal impact on the type of adjuvant systemic therapy and radiotherapy. However, the extent of axillary surgery was relevantly affected and FNR was improved by TAD.

Invasive Lobular Carcinoma of the Breast: Ongoing Trials, Challenges, and Future Directions

Purpose of Review

Invasive lobular carcinoma (ILC) is increasingly recognized as a distinct subtype of breast cancer with unique management challenges. We reviewed currently available clinical trials for patients with ILC.

Recent Findings

We describe the rationale for and study design of clinical trials for patients with both early stage and metastatic ILC. Molecular alterations specific to or enriched in ILC may serve as treatment targets.

Summary

ILC has specific features that may be treatment targets. Clinical trials for ILC are available and being developed.

The Role of Oncotype DX® Recurrence Score in Predicting Axillary Response After Neoadjuvant Chemotherapy in Breast Cancer

INTRODUCTION

Oncotype DX^® recurrence score (RS) is well-recognized for guiding decision making in adjuvant chemotherapy; however, the predictive capability of this genomic assay in determining axillary response to neoadjuvant chemotherapy (NCT) has not been established.

METHODS

Using the National Cancer Data Base (NCDB), we identified patients diagnosed with T1-T2, clinically N1/N2, estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER +/HER2 -) invasive ductal carcinoma of the breast between 2010 and 2015. Patients with an Oncotype DX^® RS who received NCT were included. RS was defined as low (< 18), intermediate (18-30), or high (> 30). Unadjusted and adjusted analyses were performed to determine the association between axillary pathologic complete response (pCR) and RS.

RESULTS

This study included a total of 158 women. RS was low in 56 (35.4%) patients, intermediate in 62 (39.2%) patients, and high in 40 (25.3%) patients. The majority of patients presented with clinical N1 disease (89.2%). Axillary pCR was achieved in 23 (14.6%) patients. When stratifying patients with axillary pCR by RS, 11 (47.8%) patients had a high RS, 6 (26.1%) patients had an intermediate RS, and 6 (26.1%) patients had a low RS. Comparing cohorts by RS, 27.5% of patients with high RS tumors had an axillary pCR, compared with only 9.7% in the intermediate RS group, and 10.7% in the low RS group (p = 0.0268).

CONCLUSION

Our findings demonstrate that Oncotype DX^® RS is an independent predictor of axillary pCR in patients with ER +/HER2 - breast cancers receiving NCT. A greater proportion of patients with a high RS achieved axillary pCR. These results support Oncotype DX^® as a tool to improve clinical decision making in axillary management.

A nomogram for determining the disease-specific survival in invasive lobular carcinoma of the breast: A population study

We aimed to establish and validate a nomogram for predicting the disease-specific survival of invasive lobular carcinoma (ILC) patients.The Surveillance, Epidemiology, and End Results program database was used to identify ILC from 2010 to 2015, in which the data was extracted from 18 registries in the US. Multivariate Cox regression analysis was performed to identify independent prognostic factors and a nomogram was constructed to predict the 3-year and 5-year survival rates of ILC patients based on Cox regression. Predictive values were compared between the new model and the American Joint Committee on Cancer staging system using the concordance index, calibration plots, integrated discrimination improvement, net reclassification improvement, and decision-curve analyses.In total, 4155 patients were identified. After multivariate Cox regression analysis, nomogram was established based on a new model containing the predictive variables of age, the primary tumor site, histology grade, American Joint Committee on Cancer TNM (tumor node metastasis) stages II, III, and IV, breast cancer subtype, therapy modality (surgery and chemotherapy). The concordance index for the training and validation cohorts were higher for the new model (0.781 and 0.832, respectively) than for the old model (0.733 and 0.779). The new model had good performance in the calibration plots. Net reclassification improvement and integrated discrimination improvement were also improved. Finally, decision-curve analyses demonstrated that the nomogram was clinically useful.We have developed a reliable nomogram for determining the prognosis and treatment outcomes of ILC. The new model facilitates the choosing of superior medical examinations and the optimizing of therapeutic regimens with cooperation among oncologists.

Evaluation of Breast and Axillary Lymph Node Specimens in Breast Cancer Patients Treated With Neoadjuvant Systemic Therapy

Breast and axillary lymph node specimens from breast cancer patients treated with neoadjuvant systemic therapy are being encountered by pathologists with increasing frequency. Evaluation of these specimens presents challenges that differ from those encountered during the examination of other types of breast specimens. This article reviews the key issues regarding the gross and microscopic evaluation of post-neoadjuvant systemic therapy breast and lymph node specimens, and emphasizes the importance of accurate specimen evaluation in assessing treatment response.