Primary systemic chemotherapy of invasive lobular carcinoma of the breast

Nomograms to predict the long-term prognosis for non-metastatic invasive lobular breast carcinoma: a population-based study

Invasive lobular breast carcinoma (ILC) is one potential subset that "clinicopathologic features" can conflict with "long-term outcome" and the optimal management strategy is unknown in such discordant situations. The present study aims to predict the long-term, overall survival (OS) and cancer-specific survival (CSS) of ILC. The clinical information of patients with non-metastatic ILC was retrieved from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2020. A total of 31451 patients were enrolled and divided into the training cohort (n=22,017) and validation cohort (n=9434). The last follow-up was December, 31, 2020 and the median follow-up period was 99 months (1-203). Age, marriage, estrogen (ER) status, progesterone (PR) status, grade, tumor size, lymph node ratio (LNR) and combined summary (CS) stage were prognostic factors for both OS and CSS of ILC, whereas chemotherapy and radiation were independent protect factors for OS. The nomograms exhibited satisfactory discriminative ability. For the training and validation cohorts, the C-index of the OS nomogram was 0.765 (95% CI 0.762-0.768) and 0.757 (95% CI 0.747-0.767), and the C-index of the CSS nomogram were 0.812 (95% CI 0.804-0.820) and 0.813 (95% CI 0.799-0.827), respectively. Additionally, decision curve analysis (DCA) demonstrated that the nomograms had superior predictive performance than traditional American Joint Committee on Cancer (AJCC) TNM stage. The novel nomograms to predict long-term prognosis based on LNR are reliable tools to predict survival, which may assist clinicians in identifying high-risk patients and devising individual treatments for patients with ILC. Our findings should aid public health prevention strategies to reduce cancer burden. We provide two R/Shiny apps ( https://ilc-survival2024.shinyapps.io/osnomogram/ ; https://ilc-survival2024.shinyapps.io/cssnomogram/ ) to visualize findings.

Effect of histological breast cancer subtypes invasive lobular versus non-special type on survival in early intermediate-to-high-risk breast carcinoma: results from the SUCCESS trials

BACKGROUND

Invasive lobular breast carcinomas (ILC) have different histological features compared to non-special type carcinomas (NST), but the effect of histological subtypes on survival is controversial. In this study, we compared clinicopathological characteristics and outcomes between ILC and NST based on a large pooled data set from three adjuvant breast cancer trials (SUCCESS A, B, and C) and investigated a potential differential effect of recurrence risk related to nodal stage on survival.

METHODS

From 2005 to 2017, the large randomized controlled SUCCESS A, B, and C trials enrolled 8190 patients with primary, intermediate-to-high-risk breast carcinoma. All patients received adjuvant chemotherapy, and endocrine and/or HER2-targeted treatment was given where appropriate. Survival outcomes in terms of disease-free survival (DFS), overall survival (OS), breast cancer-specific survival (BCSS), and distant disease-free survival (DDFS) were estimated using the Kaplan-Meier method and analyzed using log-rank tests as well as univariable and adjusted multivariable Cox regression models.

RESULTS

In the SUCCESS trials, 6284 patients had NST and 952 had ILC. The median follow-up time was 64 months. ILC patients were older, more likely to receive mastectomy, and more likely to have larger tumor sizes, lymph node infiltration, hormone receptor-positive, HER2neu-negative, and luminal A-like tumors than NST patients. In the overall cohort, no significant differences between ILC and NST were detectable regarding the four survival endpoints, with hazard ratios obtained in adjusted multivariable cox regressions of 0.96 (95% CI 0.77-1.21, p = 0.743) for DFS, 1.13 (95% CI 0.85-1.50, p = 0.414) for OS, 1.21 (95% CI 0.89-1.66, p = 0.229) for BCSS, and 0.95 (95% CI 0.73-1.24, p = 0.689) for DDFS. However, a differential effect of nodal stage on survival was observed, with better survival for ILC patients with pN0/pN1 tumors and worse survival for ILC patients with pN2/pN3 tumors compared to NST patients.

CONCLUSIONS

Our results revealed that ILC was associated with worse survival compared to NST for patients at high risk of recurrence due to advanced lymph node infiltration. These findings should be taken into account for treatment decisions and monitoring.

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.

Identifying breast cancer patients at risk of relapse despite pathological complete response after neoadjuvant therapy

This retrospective pooled analysis aims to identify factors predicting relapse despite a pathologic complete response (pCR) in patients with breast cancer (BC). 2066 patients with a pCR from five neoadjuvant GBG/AGO-B trials fulfill the inclusion criteria of this analysis. Primary endpoint is disease-free survival (DFS); secondary endpoints is distant DFS (DDFS) and overall survival (OS). After a median follow-up of 57.6 months, DFS is significantly worse for patients with positive lymph nodes (cN+ vs cN0 hazard ratio [HR] 1.94, 95%CI 1.48-2.54; p < 0.001). In patients with triple-negative tumors, lobular histology (lobular vs other HR 3.55, 95%CI 1.53-8.23; p = 0.003), and clinical nodal involvement (cN+ vs cN0 HR 2.45, 95%CI 1.59-3.79; p < 0.001) predict a higher risk of DFS events. Patients with HER2-positive cT3/4 tumors have a significantly higher risk of relapse (cT3/4 vs cT1 HR 2.07, 95%CI 1.06-4.03; p = 0.033). Initial tumor load and histological type predict relapse in patients with a pCR.

Efficacy of chemotherapy in patients with HR+/HER2-Invasive lobular breast cancer

INTRODUCTION

Invasive Lobular Breast Cancer (ILC) harbors unique clinicopathologic features. Data on optimal treatment modalities focusing on ILC remain scarce. We aim to investigate the benefit of chemotherapy in early-stage hormone receptor-positive (HR+) and human epidermal growth factor receptor-2 negative (HER2-) ILC.

METHODS

Female patients with early HR+/HER2- ILC (stages I-III) who underwent surgery were selected from the National Cancer Database (2010-2016) and grouped into four treatment cohorts: surgery only(S), chemotherapy alone (CT), endocrine therapy alone (ET), and combined chemotherapy followed by endocrine therapy (CET). Descriptive and bi-variate statistics summarized baseline characteristics and compared them across cohorts. A secondary analysis accounting for OncotypeDX (ODX) information was performed, stratifying for low (<26) and high (≥26) ODX. Kaplan-Meier (KM) and Cox proportional hazard models evaluated the relationship between treatment modality and overall survival (OS), stratifying for ODX scoring.

RESULTS

N = 15,271 patients were included. The CET cohort (29.8%) was more likely to be younger and have no co-morbidities, advanced tumor stage or high ODX score (≥26). No significant difference in OS comparing ET to CET (HR:1.08, 95%CI:0.93-1.26, p = 0.31) was observed, adjusting for confounders. N = 5,561 patients had ODX results available. No significant difference in 5-year OS was observed comparing the ET to CET cohorts, both in patients an ODX score <26 (HR:1.10; 95%CI:0.69-1.76, p = 0.69) and ODX score ≥26 (HR:1.18; 95%CI:0.51-2.75, p = 0.69).

CONCLUSION

Chemotherapy demonstrated no added survival benefit in HR+/HER2- ILC, even in tumors with ODX ≥26. Prospective trials identifying potential subgroups of patients with ILC who could benefit from chemotherapy are needed.

Management of HR+/HER2+ lobular breast cancer and trends do not mirror better outcomes

PURPOSE

Treatment protocols for invasive lobular breast cancer (ILC) have largely followed those for invasive ductal breast cancer. This study compares treatment outcomes of endocrine therapy versus combined chemo-endocrine therapy in hormone-receptor-positive (HR+), HER2-positive (HER2+) ILC tumors in a large national registry.

METHODS

We sampled the National Cancer Database (2010-2016) for female patients with stages I-III, HR+/HER2+ ILC who underwent surgery. Cochran-Armitage trend test examined trends of treatment regimen administration: Surgery only (S), chemotherapy (C), endocrine therapy (ET), and combined chemo-endocrine therapy (CET), with or without anti-HER2 therapy. Cox proportional hazard model were used to compare overall survival (OS) across ET and CET cohorts, stratifying for anti-HER2 therapy, before and after propensity score match of cohorts (2013-2016). Kaplan-Meier (KM) survival curves were also produced.

RESULTS

N=11,421 were included. 58.7% of patients received Anti-Her2 therapy after 2013. CET conferred better OS over ET in the unmatched (adjusted-5-year-OS: 92.5% vs. 81.1%, p<0.001) and PS-matched (90.4% vs. 84.5%, p=0.001) samples. ET caused lower OS in patients who received Anti-Her2 therapy (HR: 2.56, 95% CI: 1.60-4.12, p<0.001) and patients who did not (HR: 1.84, 95% CI: 1.21-2.78, p=0.004), as compared to CET on multivariable analysis. KM modeling showed highest OS in the CET cohort who received Anti-Her2 (93.0%), followed by the CET cohort who did not receive Anti-Her2 (90.2%) (p=0.06).

CONCLUSION

Chemotherapy followed by endocrine therapy and Anti-Her2 therapy was shown to be the most effective treatment modality in HR+/HER2+ ILC, contrasting previous data on the inconclusive benefit of chemotherapy in patients with ILC.

Model Development of CDK4/6 Predicted Efficacy in Patients With Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Advanced or Metastatic Breast Cancer

PURPOSE

Three cyclin-dependent kinase 4/6 inhibitors (CDKIs) are approved by the US Food and Drug Administration for the treatment of patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced or metastatic breast cancer in combination with hormonal therapy (HT). We hypothesized that on an individual basis, efficacy outcomes and adverse event (AE) development can be predicted using baseline patient and tumor characteristics.

METHODS

Individual-level data from seven randomized controlled trials submitted to the US Food and Drug Administration for new or supplemental marketing applications of CDKIs were pooled. Progression-free survival (PFS), overall survival (OS), and AE prediction models were developed for specific treatment regimens (HT v HT plus CDKI). An individual's characteristics were used in all models simultaneously to create a group of predicted outcomes that are comparable across treatment settings.

RESULTS

Accuracy of the PFS and OS prediction models for HT were 66% and 64%, respectively, with the strongest predictors being menopausal status and therapy line. The corresponding AE prediction models resulted in an average area under the curve of 0.613. Accuracy of the PFS and OS prediction models for HT plus CDKI were 62% and 63%, respectively, with the strongest predictors being histologic grade for both. The corresponding AE prediction models resulted in an average area under the curve of 0.639.

CONCLUSION

This exploratory analysis demonstrated that models of efficacy outcomes and AE development can be developed using baseline patient and tumor characteristics. Comparison of paired models can inform treatment selection for individuals on the basis of the patient's personalized goals and concerns. Although use of CDKIs is standard of care in the first- or second-line setting, this model provides prognostic information that may inform individual treatment decisions.

Changes in Management Strategy and Impact of Neoadjuvant Therapy on Extent of Surgery in Invasive Lobular Carcinoma of the Breast: Analysis of the National Cancer Database (NCDB)

Background

Given reports of low response rates to neoadjuvant chemotherapy (NAC) in invasive lobular carcinoma (ILC), we evaluated whether use of alternative strategies such as neoadjuvant endocrine therapy (NET) is increasing. Additionally, we investigated whether NET is associated with more breast conservation surgery (BCS) and less extensive axillary surgery in those with ILC.

Patients and Methods

We queried the NCDB from 2010 to 2016 and identified all women with stage I–III hormone receptor positive, human epidermal growth factor receptor-2 negative (HR+/HER2−) ILC who underwent surgery. We used Cochrane–Armitage tests to evaluate trends in utilization of the following treatment strategies: NAC, short-course NET, long-course NET, and primary surgery. We compared rates of BCS and extent of axillary surgery stratified by clinical stage and tumor receptor subtype for each treatment strategy.

Results

Among 69,312 cases of HR+/HER2− ILC, NAC use decreased slightly (from 4.7 to 4.2%, p = 0.007), while there was a small but significant increase in long-course NET (from 1.6 to 2.7%, p < 0.001). Long-course NET was significantly associated with increased BCS in patients with cT2–cT4 disease and less extensive axillary surgery in clinically node positive patients with HR+/HER2− tumors.

Conclusions

Primary surgery remains the most common treatment strategy in patients with ILC. However, NAC use decreased slightly over the study period, while the use of long-course NET had a small increase and was associated with more BCS and less extensive axillary surgery.

Neoadjuvant chemotherapy in hormone receptor-positive/HER2-negative early breast cancer: When, why and what?

Indication for neoadjuvant chemotherapy (NACT) in HR+/HER2-negative tumors is controversial. Pathological complete response (pCR) rates range from 0 to 18 % while breast-conserving surgery (BCS) is achievable in up to 60 % of tumors. No pathological feature definitely predicts pCR; lobular and molecular luminal A tumors are less likely to achieve pCR although experiencing better outcomes. Luminal B subtype, high proliferation, lack of progesterone receptor, high tumor-infiltrating lymphocytes are positively associated with increased pCR rates but worse outcomes and the prognostic role of pCR is inconsistent across studies. Molecular intrinsic subtyping and genomic signatures appear as more accurate predictors of benefit from NACT, but larger studies are needed. Anthracycline and taxane-based chemotherapy remains the standard NACT; however, CDK 4/6 inhibitors and immune checkpoint inhibitors are under evaluation. In conclusion, NACT may be proposed for luminal tumors requiring downsizing for BCS after multidisciplinary evaluation, provided that other contraindications to BCS are excluded.

Lobular Breast Cancer: A Review

Invasive lobular carcinoma accounts for 5%-15% of all invasive breast cancers, with a marked increase in incidence rates over the past two decades. Distinctive biological hallmarks of invasive lobular carcinoma include the loss of cell adhesion molecule E-cadherin leading to cells with a discohesive morphology, proliferating into single-file strands and estrogen receptor positivity. These key molecular features can make diagnosis difficult, as invasive lobular carcinoma is challenging to detect both physically and with current standard imaging. Treatment of invasive lobular carcinoma strongly favors endocrine therapy due to low chemosensitivity and lower rates of pathological response as a result. This review will summarize the distinct biological and molecular features of invasive lobular carcinoma, focusing on the diagnostic challenges faced and the subsequent surgical and medical management strategies. Prospective therapeutic options will also be explored, highlighting how furthering our understanding of the unique biology of lobular breast carcinoma is essential in guiding and informing the treatment of patients in the future.

Comparison of Overall Survival Between Invasive Lobular Breast Carcinoma and Invasive Ductal Breast Carcinoma: A Propensity Score Matching Study Based on SEER Database

Objective

Invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC) account for most breast cancers. However, the overall survival (OS) differences between ILC and IDC remain controversial. This study aimed to compare nonmetastatic ILC to IDC in terms of survival and prognostic factors for ILC.

Methods

This retrospective cohort study used data from the Surveillance, Epidemiology and End Results (SEER) Cancer Database (www.seer.cancer.gov). Women diagnosed with nonmetastatic ILC and IDC between 2006 and 2016 were included. A propensity score matching (PSM) method was used in our analysis to reduce baseline differences in clinicopathological characteristics and survival outcomes. Kaplan-Meier curves and log-rank test were used for survival analysis.

Results

Compared to IDC patients, ILC patients were diagnosed later in life with poorly differentiated and larger lesions, as well as increased expression of estrogen receptors (ERs) and/or progesterone receptors (PRs). A lower rate of radiation therapy and chemotherapy was observed in ILC. After PSM, ILC, and IDC patients exhibited similar OS (HR=1.017, p=0.409, 95% CI: 0.967–1.069). In subgroup analysis of HR-negative, AJCC stage III, N2/N3 stage patients, or those who received radiotherapy, ILC patients exhibited worse OS compared to IDC patients. Furthermore, multivariate analysis revealed a 47% survival benefit for IDC compared to ILC in HR-negative patients who received chemotherapy (HR=1.47, p=0.01, 95% CI: 1.09–1.97).

Conclusions

Our results demonstrated that ILC and IDC patients had similar OS after PSM. However, ILC patients with high risk indicators had worse OS compared to IDC patients by subgroup analysis.

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.

Differential impact of prognostic parameters in hormone receptor-positive lobular breast cancer

BACKGROUND

Invasive lobular breast cancer (BC) is the second most common BC subtype. Prognostic parameters (tumor classification, lymph node status, histologic grade, Oncotype DX recurrence score [RS], progesterone receptor status, and Ki67 index) were retrospectively studied in a large, prospective clinical trial encompassing 2585 patients who had hormone receptor-positive early BC (the West German Study Group PlanB trial).

METHODS

BCs were centrally reviewed and classified as lobular (n = 353; 14%) or nonlobular (n = 2232; 86%). The median follow-up was 60 months. Five-year disease-free survival (DFS) estimates were obtained using the Kaplan-Meier method. Prognostic parameters were evaluated using Cox proportional hazard models.

RESULTS

Lobular BC was associated with higher tumor classification, higher lymph node status, lower histologic grade, lower Ki67 index, and low or intermediate RS. The prevalence of high RS (RS range, 26-100) was 3-fold lower in patients who had lobular BC compared with those who had nonlobular BC (8% vs 24%; P < .001). However, 5-year DFS estimates for lobular and nonlobular BC were similar (92.1% and 92.3%, respectively; P = .673). In multivariate analyses, prognostic parameters for DFS in lobular BC included grade 3 (hazard ratio, 5.06; 95% CI, 1.91-13.39) and a pathologic lymph node status (pN) of pN3 (hazard ratio, 12.16; 95% CI, 3.87-38.24), but not RS. By contrast, prognostic parameters in nonlobular BC included grade 3 (hazard ratio, 1.65; 95% CI, 1.11-2.44), pN3 (hazard ratio, 3.68; 95% CI, 1.60-8.46), and high RS (hazard ratio, 2.49; 95% CI, 1.69-3.68).

CONCLUSIONS

Lobular BC is associated with low and intermediate RS, although 5-year DFS is similar to that of nonlobular BC. The effect of the RS in lobular BC appears to be distinct from that in nonlobular BC. For risk assessment, the RS needs to be complemented by clinicopathologic parameters for therapy decision making.

Management of Breast Cancer During the COVID-19 Pandemic: A Stage- and Subtype-Specific Approach

The COVID-19 pandemic has rapidly changed delivery of cancer care. Many nonurgent surgeries are delayed to preserve hospital resources, and patient visits to health care settings are limited to reduce exposure to SARS-CoV-2. Providers must carefully weigh risks and benefits of delivering immunosuppressive therapy during the pandemic. For breast cancer, a key difference is increased use of neoadjuvant systemic therapy due to deferral of many breast surgeries during the pandemic. In some cases, this necessitates increased use of genomic tumor profiling on core biopsy specimens to guide neoadjuvant therapy decisions. Breast cancer treatment during the pandemic requires multidisciplinary input and varies according to stage, tumor biology, comorbidities, age, patient preferences, and available hospital resources. We present here the Johns Hopkins Women's Malignancies Program approach to breast cancer management during the COVID-19 pandemic. We include algorithms based on tumor biology and extent of disease that guide management decisions during the pandemic. These algorithms emphasize medical oncology treatment decisions and demonstrate how we have operationalized the general treatment recommendations during the pandemic proposed by national groups, such as the COVID-19 Pandemic Breast Cancer Consortium. Our recommendations can be adapted by other institutions and medical oncology practices in accordance with local conditions and resources. Guidelines such as these will be important as we continue to balance treatment of breast cancer against risk of SARS-CoV-2 exposure and infection until approval of a vaccine.

Adjuvant chemotherapy could not bring survival benefit to HR-positive, HER2-negative, pT1b-c/N0-1/M0 invasive lobular carcinoma of the breast: a propensity score matching study based on SEER database

BACKGROUND

The benefit of adjuvant chemotherapy in invasive lobular carcinoma (ILC) is still unclear. The objective of the current study was to elucidate the effectiveness of adjuvant chemotherapy in hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative, pT1b-c/N0-1/M0 ILC.

METHODS

Based on Surveillance, Epidemiology, and End-Results (SEER) database, we identified original 12,334 HR-positive, HER2-negative, pT1b-c/N0-1/M0 ILC patients, who were then divided into adjuvant chemotherapy group and control group. End-points were overall survival (OS) and breast cancer-specific mortality (BCSM). Aiming to minimize the selection bias of baseline characteristics, Propensity Score Matching (PSM) method was used.

RESULTS

In a total of 12,334 patients with HR-positive, HER2-negative, pT1b-c/N0-1/M0 ILC, 1785 patients (14.5%) were allocated into adjuvant chemotherapy group and 10,549 (85.5%) into control group. Used PSM, the 1785 patients in adjuvant chemotherapy group matched to the 1785 patients in control group. By Kaplan-Meier survival analyses, we observed no beneficial effect of adjuvant chemotherapy on OS in both original samples (P = 0.639) and matched samples (P = 0.962), however, ineffective or even contrary results of adjuvant chemotherapy on BCSM both in original samples (P = 0.001) and in matched samples (P = 0.002). In both original and matched multivariate Cox models, we observed ineffectiveness of adjuvant chemotherapy on OS (hazard ratio (HR) for overall survival = 0.82, 95% confidence interval (CI) [0.62-1.09]; P = 0.172 and HR = 0.90, 95%CI [0.65-1.26]; P = 0.553, respectively), unexpectedly promoting effect of adjuvant chemotherapy on BCSM (HR = 2.33, 95%CI [1.47-3.67]; P = 0.001 and HR = 2.41, 95%CI [1.32-4.39]; P = 0.004, respectively). Standard surgery was beneficial to the survival of patients. Lymph node metastasis was detrimental to survival and radiotherapy brought survival benefit in original samples, but two issues had unobvious effect in matched samples.

CONCLUSION

In this study, adjuvant chemotherapy did not improve survival for patients with HR-positive, HER2-negative pT1b-c/N0-1/M0 ILC.

Response of metastatic mouse invasive lobular carcinoma to mTOR inhibition is partly mediated by the adaptive immune system

Effective treatment of invasive lobular carcinoma (ILC) of the breast is hampered by late detection, invasive growth, distant metastasis, and poor response to chemotherapy. Phosphoinositide 3-kinase (PI3K) signaling, one of the major druggable oncogenic signaling networks, is frequently activated in ILC. We investigated treatment response and resistance to AZD8055, an inhibitor of mammalian target of rapamycin (mTOR), in the K14-cre;Cdh1^Flox/Flox;Trp53^Flox/Flox (KEP) mouse model of metastatic ILC. Inhibition of mTOR signaling blocked the growth of primary KEP tumors as well as the progression of metastatic disease. However, primary tumors and distant metastases eventually acquired resistance after long-term AZD8055 treatment, despite continued effective suppression of mTOR signaling in cancer cells. Interestingly, therapeutic responses were associated with increased expression of genes related to antigen presentation. Consistent with this observation, increased numbers of tumor-infiltrating major histocompatibility complex class II-positive (MHCII+) immune cells were observed in treatment-responsive KEP tumors. Acquisition of treatment resistance was associated with loss of MHCII+ cells and reduced expression of genes related to the adaptive immune system. The therapeutic efficacy of mTOR inhibition was reduced in Rag1^−/- mice lacking mature T and B lymphocytes, compared to immunocompetent mice. Furthermore, therapy responsiveness could be partially rescued by transplanting AZD8055-resistant KEP tumors into treatment-naïve immunocompetent hosts. Collectively, these data indicate that the PI3K signaling pathway is an attractive therapeutic target in invasive lobular carcinoma, and that part of the therapeutic effect of mTOR inhibition is mediated by the adaptive immune system.

The impact of chemotherapy sequence on survival in node-positive invasive lobular carcinoma

BACKGROUND AND OBJECTIVES

We sought to evaluate the impact of chemotherapy sequence on survival by comparing node-positive invasive lobular carcinoma (ILC) patients who received neoadjuvant (NACT) and adjuvant (ACT) chemotherapy.

METHODS

cT1-4c, cN1-3 ILC patients in the National Cancer Data Base (2004-2013) who underwent surgery and chemotherapy were divided into NACT and ACT cohorts. Kaplan-Meier curves and Cox proportional hazards modeling were used to estimate unadjusted and adjusted overall survival (OS), respectively.

RESULTS

Five thousand five hundred fifty-one (35.6%) of 15 573 ILC patients treated with chemotherapy received NACT. NACT patients had similar rates of pT3/4 disease (26.6% vs 26.2%), nodal involvement (median 3 vs 4), and number of lymph nodes examined (median 13 vs 14) but higher rates of mastectomy (81.8% vs 74.5%, P < 0.001) vs ACT patients. 3.4% of NACT patients experienced pathologic complete response (pCR). Unadjusted 10-year OS was worse for NACT vs ACT patients (65.1% vs 54.4%, log-rank P < 0.001). After adjustment for known covariates, NACT continued to be associated with worse OS (hazard ratio [HR], 1.38; 95% confidence interval [CI], 1.25-1.52).

CONCLUSIONS

In node-positive ILC, NACT yielded low rates of pCR, was not associated with lower rates of mastectomy or less extensive axillary surgery, and was associated with worse survival vs ACT, suggesting limited benefit for these patients.

Impact of invasive lobular carcinoma on long-term outcomes in Mexican breast cancer patients

PURPOSE

The aim of this study was to compare the difference in disease-free survival (DFS) and overall survival (OS) between invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC) in our Hispanic population with breast cancer (BC).

METHODS

We retrospectively analyzed a database of 4533 non-metastatic BC patients treated for BC at the National Cancer Institute in Mexico (INCan) between 2006 and 2016. We compared clinical characteristics, treatment and survival between women with invasive ductal and invasive lobular BC. We evaluated differences between survival curves with the log-rank test and used Cox's proportional hazards model for the multivariate analysis.

RESULTS

Median follow-up time was 42.13 months (IQ₂₅ 25.2-IQ₇₅ 72.06). The median age was 50.9 years (IQ₂₅ 43.5-IQ₇₅ 59.8). DFS at 5 years was 80.8% for IDC versus 76.2% for ILC. 5 years OS was 88.7% for IDC versus 84.3% for ILC. Multivariate analysis showed that factors that negatively affected the 5-year DFS include: clinical stage III [hazard ratio (HR) 4.2, 95% CI 3.36-5.35; p < 0.001], triple negative phenotype (HR 1.4, 95% CI 1.08-1.81; p = 0.009), Ki67 ≥ 18 (HR 1.6, 95% CI 1.28-2.11; p < 0.001), and lobular histological type (HR 1.6, 95% CI 1.09-2.49; p = 0.017). Factors associated with a negative impact on OS were: clinical stage III (HR 4.5, 95% CI 3.15-6.54; p < 0.001), triple negative phenotype (HR 2.4, 95% CI 1.69-3.48; p < 0.001), and Ki67 ≥ 18% (HR 1.9, 95% CI 1.27-2.92; p = 0.02).

CONCLUSION

Our results highlight the different biology of ILC and show that long-term prognosis in terms of DFS is not as favorable as previously reported.

21-gene recurrence score and adjuvant chemotherapy decisions in patients with invasive lobular breast cancer

Aim: To determine the effect of the 21-gene recurrence score (RS) on outcome and chemotherapy decision in breast invasive lobular carcinoma (ILC). Materials & methods: We included 6467 patients with early stage and estrogen receptor–positive ILC from the Surveillance, epidemiology, and end results database. Results: A total of 9.1, 31.4, and 70.1% of patients with low-, intermediate-, and high-risk RS groups received chemotherapy, respectively. A higher RS was independently associated with poor breast cancer-specific survival, and receipt of chemotherapy was not related to better breast cancer-specific survival in low-, intermediate-, or high-risk RS groups. Conclusion: The 21-gene RS could impact chemotherapy decision making in early-stage ILC. However, adjuvant chemotherapy does not appear to improve outcome in high-risk RS cohort.

Mixed Invasive Ductal and Lobular Carcinoma of the Breast: Prognosis and the Importance of Histologic Grade

BACKGROUND

The diagnosis of mixed invasive ductal and lobular carcinoma (IDC-L) in clinical practice is often associated with uncertainty related to its prognosis and response to systemic therapies. With the increasing recognition of invasive lobular carcinoma (ILC) as a distinct disease subtype, questions surrounding IDC-L become even more relevant. In this study, we took advantage of a detailed clinical database to compare IDC-L and ILC regarding clinicopathologic and treatment characteristics, prognostic power of histologic grade, and survival outcomes.

MATERIALS AND METHODS

In this retrospective cohort study, we identified 811 patients diagnosed with early-stage breast cancer with IDC-L or ILC. Descriptive statistics were performed to compare baseline clinicopathologic characteristics and treatments. Survival rates were subsequently analyzed using the Kaplan-Meier method and compared using the Cox proportional hazards model.

RESULTS

Patients with ILC had more commonly multifocal disease, low to intermediate histologic grade, and HER2-negative disease. Histologic grade was prognostic for patients with IDC-L but had no significant discriminatory power in patients with ILC. Among postmenopausal women, those with IDC-L had significantly better outcomes when compared with those with ILC: disease-free survival (DFS) and overall survival (OS; adjusted hazard ratio [HR], 0.54; 95% confidence interval [CI] 0.31-0.95). Finally, postmenopausal women treated with an aromatase inhibitor had more favorable DFS and OS than those treated with tamoxifen only (OS adjusted HR, 0.50; 95% CI, 0.29-0.87), which was similar for both histologic types (p = .212).

CONCLUSION

IDC-L tumors have a better prognosis than ILC tumors, particularly among postmenopausal women. Histologic grade is an important prognostic factor in IDC-L but not in ILC.

IMPLICATIONS FOR PRACTICE

This study compared mixed invasive ductal and lobular carcinoma (IDC-L) with invasive lobular carcinomas (ILCs) to assess the overall prognosis, the prognostic role of histologic grade, and response to systemic therapy. It was found that patients with IDC-L tumors have a better prognosis than ILC, particularly among postmenopausal women, which may impact follow-up strategies. Moreover, although histologic grade failed to stratify the risk of ILC, it showed an important prognostic power in IDC-L, thus highlighting its clinical utility to guide treatment decisions of IDC-L. Finally, the disease-free survival advantage of adjuvant aromatase inhibitors over tamoxifen in ILC was consistent in IDC-L.

Characterizing Response to Neoadjuvant Chemotherapy in Invasive Lobular Breast Carcinoma

BACKGROUND

Pathological complete response (pCR) after neoadjuvant chemotherapy (NCT) for breast cancer is associated with improved survival and facilitates conservative surgical strategies. Invasive lobular carcinoma (ILC) has been observed to have decreased response to NCT compared with invasive ductal carcinoma (IDC). This study seeks to evaluate national trends in the use of NCT for ILC compared with IDC, and determine if there is a subset of ILC patients who demonstrate favorable response rates.

METHODS

This is a study using the National Cancer Database. The cohort consisted of patients with stage 1-3 ILC treated between 2010 and 2014, and a reference cohort of patient with IDC. For patients receiving NCT, pCR was assessed and clinically relevant variables were used in multivariable logistic regression models for each histologic subtype, modeling for pCR achievement. Survival analysis was performed for each histologic group to evaluate potential survival benefits of achieving pCR.

RESULTS

Our study cohort consisted of 384,887 women, of which 9.7% had ILC. A significantly lower rate of pCR after NCT was found in the cases of ILC compared with those of IDC (8.7% versus 23.2%). Increased response was seen in ILC patients with HER2-positive and TNBC subtypes. A survival benefit was demonstrated in patients with ILC who achieved pCR.

CONCLUSIONS

While response to NCT in patients with ILC is uncommon, our findings demonstrate a selective benefit for patients with HER2-positive tumors and TNBC. In addition, pCR is correlated with a clear survival advantage in ILC.

Estrogen and progesterone receptor expression levels do not differ between lobular and ductal carcinoma in patients with hormone receptor-positive tumors

Background

Differences in estrogen (ER) and progesterone (PR) expression between invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC) could be an underlying reason for the difference in chemo-sensitivity and response to hormonal therapy between ILC and IDC. The aim of this study was to investigate the differences in ER and PR expression levels between postmenopausal patients with hormonal receptor-positive ILC and IDC.

Methods

We included all ER and/or PR receptor-positive ILC and IDC, diagnosed between January 2011 and December 2013 from the population-based Netherlands Cancer Registry. A semi-quantitative classification was used to analyze differences in ER/PR expression, which consisted of three ER expression classes: 10–69, 70–89, and ≥90%. Differences in ER and PR expression levels between IDC and ILC were analyzed according to age group, tumor size, axillary nodal status, grade, and HER2 status.

Results

In total, 26,339 ER and/or PR-positive breast cancers were included in the study, of which 17% were ILC and 83% IDC. In patients with IDC, 86% of the tumors showed an ER expression level of 90% or more, compared to 84% in those with ILC. In both IDC and ILC a PR expression level of 90% or more was observed in 54% of the tumors. In postmenopausal patients aged 50–69 years no significant differences could be observed in ER and PR expression levels between ILC and IDC.

Conclusion

Patients with ER and PR-positive ILC and IDC have similar quantitative ER and PR expression profiles, implicating that ER/PR expression is unlikely to be a confounding factor in studies concerning chemo-sensitivity of ILC and IDC.

Molecular Classification of Lobular Carcinoma of the Breast

The morphology of breast tumors is complicated and diagnosis can be difficult. We present here a novel diagnostic model which we validate on both array-based and RNA sequencing platforms which reliably distinguishes this tumor type across multiple cohorts. We also examine how this molecular classification predicts sensitivity to common chemotherapeutics in cell-line based assays. A total of 1845 invasive breast cancer cases in six cohorts were collected, split into discovery and validation cohorts, and a classifier was created and compared to pathological diagnosis, grade and survival. In the validation cohorts the concordance of predicted diagnosis with a pathological diagnosis was 92%, and 97% when inconclusively classified cases were excluded. Tumor-derived cell lines were classified with the model as having predominantly ductal or lobular-like molecular physiologies, and sensitivity of these lines to relevant compounds was analyzed. A diagnostic tool can be created that reliably distinguishes lobular from ductal carcinoma and allows the classification of cell lines on the basis of molecular profiles associated with these tumor types. This tool may assist in improved diagnosis and aid in explorations of the response of lobular type breast tumor models to different compounds.

Gastric and colon metastasis from breast cancer: case report, review of the literature, and possible underlying mechanisms

Gastrointestinal metastases from breast cancer are not common. We present a 58-year-old female diagnosed with lobular breast cancer some years before whose relapses were gastric and colonic mucosal. Simultaneous metastases are extremely rare. To our knowledge, no cases of initial dual affectation have been reported. The patient also showed gastritis by Helicobacter pylori. Invasive lobular breast carcinoma is the most frequent special type of breast cancer and carries some specific molecular alterations such as loss of expression of E-cadherin. Although underlying mechanisms of metastasization are not entirely known, chemokines as well as inflammatory events seem to be implicated in this process. Interaction between chemokines and their receptors frequently induces cell migration. We hypothesize that H. pylori, inflammatory cells, and chemokines may create a favorable environment attracting tumor cells.

Metastatic pattern of invasive lobular carcinoma of the breast-Emphasis on gastric metastases

BACKGROUND AND OBJECTIVES

Breast invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC) have different metastatic patterns, but the exact pattern of metastases from ILC is poorly known. This study aimed to determine the frequency of ILC metastases in atypical locations, with an emphasis on gastric metastases.

METHODS

Patients with ILC treated at the Saint-Sacrement Hospital (Quebec City, Canada) and the Maisonneuve-Rosemont Hospital (Montreal, Canada) between January 2003 and December 2009 were retrospectively reviewed. Demographic, clinical, and follow-up data were retrieved from the medical charts. Metastases that were diagnosed during follow-up were recorded.

RESULTS

Among the 481 patients with ILC, 74 (15.4%) were diagnosed with metastases after a median follow-up of 46 months. Among these 74 patients, 41.9% had metastases in atypical sites. Five patients were diagnosed with histologically confirmed gastric metastases of ILC.

CONCLUSION

Metastases of breast ILC to atypical sites might be more frequent than previously reported. Clinicians should keep a high level of suspicion when a patient with a history of ILC develops digestive symptoms. It is important to differentiate metastases from a primary GI tumor by using immunohistochemical markers. J. Surg. Oncol. 2016;114:543-547. © 2016 Wiley Periodicals, Inc.

The role of histological subtype in hormone receptor positive metastatic breast cancer: similar survival but different therapeutic approaches

INTRODUCTION

This study describes the differences between the two largest histological breast cancer subtypes (invasive ductal carcinoma (IDC) and invasive (mixed) lobular carcinoma (ILC) with respect to patient and tumor characteristics, treatment-choices and outcome in metastatic breast cancer.

RESULTS

Patients with ILC were older at diagnosis of primary breast cancer and had more often initial bone metastasis (46.5% versus 34.8%, P = 0.01) and less often multiple metastatic sites compared to IDC (23.7% versus 30.9%, P = 0.11). Six months after diagnosis of metastatic breast cancer, 28.1% of patients with ILC and 39.8% of patients with IDC had received chemotherapy with a longer median time to first chemotherapy for those with ILC (P = 0.001). After six months 84.8% of patients with ILC had received endocrine therapy versus 72.5% of patients with IDC (P = 0.0001). Median overall survival was 29 months for ILC and 25 months for IDC (P = 0.53).

MATERIALS AND METHODS

We included 437 patients with hormone receptor-positive IDC and 131 patients with hormone receptor-positive ILC, all diagnosed with metastatic breast cancer between 2007-2009, irrespective of date of the primary diagnosis. Patient and tumor characteristics and data on treatment and outcome were collected. Survival curves were obtained using the Kaplan-Meier method.

CONCLUSIONS

Treatment strategies of hormone receptor-positive metastatic breast cancer were remarkably different for patients with ILC and IDC. Further research is required to understand tumor behavior and treatment-choices in real-life.

Tumor microenvironment in invasive lobular carcinoma: possible therapeutic targets

Invasive ductal and lobular carcinomas (IDC and ILC) are the two most common histological types of breast cancer, and have been considered to develop from terminal duct lobular unit but their molecular, pathological, and clinical features are markedly different between them. These differences could be due to different mechanisms of carcinogenesis and tumor microenvironment, especially cancer-associated fibroblasts (CAFs) but little has been explored in this aspect. Therefore, in this study, we evaluated the status of angiogenesis, maturation of intratumoral microvessels, and proliferation of CAFs using immunohistochemistry and PCR array analysis to explore the differences of tumor microenvironment between ILC and IDC. We studied grade- and age-matched, luminal-like ILC and IDC. We immunolocalized CD34 and αSMA for an evaluation of CAFs and CD31, Vasohibin-1, a specific marker of proliferative endothelial cells and nestin, a marker of pericytes for studying the status of proliferation and maturation of intratumoral microvessel. We also performed PCR array analysis to evaluate angiogenic factors in tumor stromal components. The number of CAFs, microvessel density, and vasohibin-1/CD31 positive ratio were all significantly higher in ILC than IDC but nestin immunoreactivity in intratumoral microvessel was significantly lower in ILC. These results did indicate that proliferation of CAFs and endothelial cells was more pronounced in ILC than IDC but newly formed microvessels were less mature than those in IDC. PCR array analysis also revealed that IGF-1 expression was higher in ILC than IDC. This is the first study to demonstrate the differences of tumor microenvironment including CAFs and proliferation and maturation of intratumoral vessels between ILC and IDC.

Is There a Role for Oncotype Dx Testing in Invasive Lobular Carcinoma?

Oncotype Dx Breast Cancer Assay is a 21-gene assay used in estrogen receptor (ER)-positive breast cancer to predict benefit from chemotherapy (CT). Tumors are placed into one of three risk categories based on their recurrence score (RS). This paper explores the impact of tumor histopathologic features and Oncotype Dx RS on the treatment plan for invasive lobular carcinoma (ILC). Invasive lobular carcinoma cases submitted for Oncotype Dx testing were identified from a clinical data base. The histopathologic and immunohistochemical features and RS subcategory of each tumor, and treatment regimen and medical oncologic assessments of each patient were reviewed. A total of 135 cases of ILC had RS testing, which represented 15% of all ILC diagnosed at the institution over the time period. 80% of ILC was of the classical subtype and all tumors were ER positive and human epidermal growth factor receptor 2 (HER-2) negative by immunohistochemistry. Sixty three percent of cases were low risk (LR), 35.5% were intermediate risk (IR) and 1.5% were high risk (HR). Both HR cases were pleomorphic ILC. Sixty eight percent of classical ILC had a LR score, while 70% of pleomorphic ILC had an IR score. Patients in the IR category were significantly more likely to undergo CT than patients in the LR category (54% versus 18%; p < 0.0001). In the LR category, those undergoing CT were significantly younger and more likely to have positive lymph nodes (p < 0.05). Qualitative analysis of medical oncologic assessments showed that RS played a role in decision-making on CT in 74% of cases overall. At our institution, Oncotype Dx RS currently plays a role in the management of a proportion of ILC and impacts on treatment decisions.

Patients with Slowly Proliferative Early Breast Cancer Have Low Five-Year Recurrence Rates in a Phase III Adjuvant Trial of Capecitabine

PURPOSE

We conducted a randomized phase III study to determine whether patients with early breast cancer would benefit from the addition of capecitabine (X) to a standard regimen of doxorubicin (A) plus cyclophosphamide (C) followed by docetaxel (T).

EXPERIMENTAL DESIGN

Treatment comprised eight cycles of AC→T (T dose: 100 mg/m(2) on day 1) or AC→XT (X dose: 825 mg/m(2) twice daily, days 1-14; T dose: 75 mg/m(2) on day 1). The primary endpoint was 5-year disease-free survival (DFS).

RESULTS

Of 2,611 women, 1,304 were randomly assigned to receive AC→T and 1,307 to receive AC→XT. After a median follow-up of 5 years, the study failed to meet its primary endpoint [HR, 0.84; 95% confidence interval (CI), 0.67-1.05; P = 0.125]. A significant improvement in overall survival, a secondary endpoint, was seen with AC→XT versus AC→T (HR, 0.68; 95% CI, 0.51-0.92; P = 0.011). There were no unexpected adverse events. Of patients with estrogen receptor (ER)-positive/HER2-negative disease, 70% of whom were node-positive, 26% and 59% had tumors with a centrally assessed Ki-67 score of <10% or <20%, respectively, and only 17 (2%) and 53 (6%) DFS events, respectively, occurred in these groups at 7 years.

CONCLUSIONS

The very low event rate in patients with ER-positive, low Ki-67 cancers, regardless of nodal status, strongly suggests that these patients should not be enrolled in adjuvant trials that assess 5-year DFS rates and that central Ki-67 analyses can identify these patients.

Differences in Response and Surgical Management with Neoadjuvant Chemotherapy in Invasive Lobular Versus Ductal Breast Cancer

Background

This study was conducted to determine the impact of neoadjuvant chemotherapy (NAC) on the likelihood of breast-conserving surgery (BCS) performed for patients with invasive lobular breast carcinoma (ILC) and invasive ductal carcinoma (IDC).

Methods

Female patients with a diagnosis of ILC or IDC in The Netherlands between July 2008 and December 2012 were identified through the population-based Netherlands Cancer Registry.

Results

A total of 466 ILC patients received NAC compared with 3622 IDC patients. Downstaging by NAC was seen in 49.7 % of the patients with ILC and in 69.6 % of the patients with IDC, and a pathologic complete response (pCR) was observed in 4.9 and 20.2 % of these patients, respectively (P < 0.0001). Breast-conserving surgery was performed for 24.4 % of the patients with ILC receiving NAC versus 39.4 % of the patients with IDC. In the ILC group, 8.2 % of the patients needed surgical reinterventions after BCS due to tumor-positive resection margins compared with 3.4 % of the patients with IDC (P < 0.0001). Lobular histology was independently associated with a higher mastectomy rate (odds ratio 1.91; 95 % confidence interval 1.49–2.44). Among the patients with clinical T2 and T3 disease, BCS was achieved more often when NAC was administered in ILC as well as IDC.

Conclusion

The patients with ILC receiving NAC were less likely to experience a pCR and less likely to undergo BCS than the patients with IDC. With regard to BCS, the impact of NAC for ILC patients was lower than for patients receiving surgery without NAC. However, despite the high number to treating in order to achieve BCS, a small subset of ILC patients, especially cT2 and cT3 patients, still may benefit from NAC.

Clinical outcome with correlation to disseminated tumor cell (DTC) status after DTC-guided secondary adjuvant treatment with docetaxel in early breast cancer

PURPOSE

The presence of disseminated tumor cells (DTCs) in bone marrow (BM) predicts survival in early breast cancer. This study explores the use of DTCs for identification of patients insufficiently treated with adjuvant therapy so they can be offered secondary adjuvant treatment and the subsequent surrogate marker potential of DTCs for outcome determination.

PATIENTS AND METHODS

Patients with early breast cancer who had completed six cycles of adjuvant fluorouracil, epirubicin, and cyclophosphamide (FEC) chemotherapy underwent BM aspiration 2 to 3 months (BM1) and 8 to 9 months (BM2) after FEC. Presence of DTCs in BM was determined by immunocytochemistry using pan-cytokeratin monoclonal antibodies. If one or more DTCs were present at BM2, six cycles of docetaxel (100 mg/m(2), once every 3 weeks) were administered, followed by DTC analysis 1 and 13 months after the last docetaxel infusion (after treatment). Cox regression analysis was used to evaluate disease-free interval (DFI).

RESULTS

Of 1,066 patients with a DTC result at BM2 and available follow-up information (median follow-up, 71.9 months from the time of BM2), 7.2% were DTC positive. Of 72 docetaxel-treated patients analyzed for DTCs after treatment, 15 (20.8%) had persistent DTCs. Patients with remaining DTCs had markedly reduced DFI (46.7% experienced relapse) compared with patients with no DTCs after treatment (adjusted hazard ratio, 7.58; 95% CI, 2.3 to 24.7). The docetaxel-treated patients with no DTCs after treatment had comparable DFI (8.8% experienced relapse) compared with those with no DTCs both at BM1 and BM2 (12.7% experienced relapse; P = .377, log-rank test).

CONCLUSION

DTC status identifies high-risk patients after FEC chemotherapy, and DTC monitoring status after secondary treatment with docetaxel correlated strongly with survival. This emphasizes the potential for DTC analysis as a surrogate marker for adjuvant treatment effect in breast cancer.

Invasive lobular breast cancer and its variants: how special are they for systemic therapy decisions?

The WHO classification of breast tumors distinguishes, besides invasive breast cancer 'of no special type' (former invasive ductal carcinoma, representing 60-70% of all breast cancers), 30 special types, of which invasive lobular carcinoma (ILC) is the most common (5-15%). We review the literature on (i) the specificity and heterogeneity of ILC biology as documented by various analytical techniques, including the results of molecular testing for risk of recurrence; (ii) the impact of lobular histology on prediction of prognosis and effect of systemic therapies in patients. Though it is generally admitted that ILC has a better prognosis than IDC, is endocrine responsive, and responds poorly to chemotherapy, currently available data do not unanimously support these assumptions. This review demonstrates some lack of specific data and a need for improving clinical research design to allow oncologists to make informed systemic therapy decisions in patients with ILC. Importantly, future studies should compare various endpoints in ILC breast cancer patients among the group of hormonosensitive breast cancer.

Impact of factors affecting the residual tumor size diagnosed by MRI following neoadjuvant chemotherapy in comparison to pathology

BACKGROUND AND OBJECTIVES

To investigate accuracy of magnetic resonance imaging (MRI) for measuring residual tumor size in breast cancer patients receiving neoadjuvant chemotherapy (NAC).

METHODS

Ninety-eight patients were studied. Several MRI were performed during NAC for response monitoring, and the residual tumor size was measured on last MRI after completing NAC. Covariates, including age, tumor characteristics, biomarkers, NAC regimens, MRI scanners, and time from last MRI to operation, were analyzed. Univariate and Multivariate linear regression models were used to determine the predictive value of these covariates for MRI-pathology size discrepancy as the outcome measure.

RESULTS

The mean (±SD) of the absolute difference between MRI and pathological residual tumor size was 1.0 ± 2.0 cm (range, 0-14 cm). Univariate regression analysis showed tumor type, morphology, HR status, HER2 status, and MRI scanner (1.5 T or 3.0 T) were significantly associated with MRI-pathology size discrepancy (all P < 0.05). Multivariate regression analyses demonstrated that only tumor type, tumor morphology, and biomarker status considering both HR and HER-2 were independent predictors (P = 0.0014, 0.0032, and 0.0286, respectively).

CONCLUSION

The accuracy of MRI in evaluating residual tumor size depends on tumor type, morphology, and biomarker status. The information may be considered in surgical planning for NAC patients.

Prognostic relevance at 5 years of the early monitoring of neoadjuvant chemotherapy using (18)F-FDG PET in luminal HER2-negative breast cancer

PURPOSE

The objective of this study was to evaluate, in the luminal human epidermal growth factor receptor 2 (HER2)-negative breast cancer subtype, the prognostic value of tumour glucose metabolism at baseline and of its early changes during neoadjuvant chemotherapy (NAC).

METHODS

This prospective study included 61 women with hormone-sensitive HER2-negative breast cancer treated with NAC. (18)F-Fluorodeoxyglucose (FDG) positron emission tomography (PET) was performed at baseline. Hepatic activity was used as a reference to distinguish between low metabolic and hypermetabolic tumours. In hypermetabolic tumours, a PET exam was repeated after the first course of NAC. The relative change in the maximum standardized uptake value of the tumour (∆SUV) was calculated.

RESULTS

Nineteen women had low metabolic luminal breast cancers at baseline, correlated with low proliferation indexes. Forty-two women had hypermetabolic tumours, corresponding to more proliferative breast cancers with higher Ki-67 expression (p = 0.017) and higher grade (p = 0.04). The median follow-up period was 64.2 months (range 11.5-93.2). Thirteen women developed recurrent disease, nine of whom died. Worse overall survival was associated with larger tumour size [>5 cm, hazard ratio (HR) = 6.52, p = 0.009] and with hypermetabolic tumours achieving a low metabolic response after one cycle of NAC (ΔSUV < 16%, HR = 10.63, p = 0.004). Five-year overall survival in these poor responder patients was 49.2%. Overall survival in women with low metabolic tumours or hypermetabolic/good response tumours was 100 and 96.15%, respectively.

CONCLUSION

In luminal HER2-negative breast tumours, tumour metabolism at baseline and changes after the first course of NAC are early surrogate markers of patients' survival. A subgroup of women with hypermetabolic/poorly responding tumours, correlated with poor prognosis at 5 years, can be identified early. These results may guide future studies by tailoring the NAC regimen to the metabolic response.

Pathologic response and long-term follow-up in breast cancer patients treated with neoadjuvant chemotherapy: a comparison between classifications and their practical application

CONTEXT

Breast cancer is increasingly treated with neoadjuvant chemotherapy to improve surgical resectability and evaluate tumor response, which is assessed histopathologically. Several histopathologic classification systems have been previously described for assessment of treatment response.

OBJECTIVES

To test performance in a side-by-side comparison of several histopathologic classification systems after neoadjuvant chemotherapy with clinical outcome.

DESIGN

Sixty-two patients were enrolled in a randomized trial receiving sequential neoadjuvant chemotherapy with doxorubicin and paclitaxel. Histologic sections from the patients' tumors sampled before (core biopsy) and after treatment (excision or mastectomy) were reviewed. Histologic response was assessed following National Surgical Adjuvant Breast and Bowel Project protocol B18, Miller-Payne grading, Sataloff tumor and nodes, Residual Cancer Burden (RCB), and Residual Disease in Breast and Nodes (RDBN). Pathologic classification results were correlated with survival using Kaplan-Meier and Cox hazards regression with a median follow-up of 93 months.

RESULTS

RDBN was associated with distant disease-free survival by univariate and multivariate analysis (P = .01 and .004, respectively), as were lymph node metastases (P = .02 and .01, respectively). Five patients (8%) had complete pathologic response after neoadjuvant chemotherapy, and none of them relapsed during the study period. Survival was shorter among patients with higher Residual Cancer Burden scores, but the associations were not significant. Miller-Payne grading and Sataloff tumor scores were not correlated with survival.

CONCLUSIONS

Evaluation of breast specimens after neoadjuvant chemotherapy by the composite index RDBN correlates with long-term outcome. The residual disease in breast and nodes system is suitable for routinely processed pathology cases. This study confirms the importance of lymph node status after neoadjuvant chemotherapy and favorable outcome in patients with pathologic complete response.

Invasive lobular carcinoma of the breast: patient response to systemic endocrine therapy and hormone response in model systems

Invasive lobular carcinoma of the breast (ILC) represents 10-15% of all newly diagnosed breast cancers, affecting ∼30,000 women annually in the United States. However, ILC is critically understudied as a breast cancer subtype. Though the vast majority of ILC are estrogen receptor-positive and present with overall favorable biomarkers, ILC patients do not benefit from improved outcomes versus other breast cancer patients. Patient outcomes, in particular in response to endocrine therapies, are not well understood in ILC, due in large part to the lack of prospective identification in large clinical trials. Further, there is a lack of laboratory models to study cell signaling, hormone response, and endocrine resistance in ILC. In this review, we provide an overview of clinicopathological features of ILC tumors, discuss issues with clinical management, and highlight the disconnect between ILC biomarkers and patient outcomes. We review currently available data on ILC patient outcomes, with a focus on response to endocrine therapy. Additionally, we describe currently available laboratory models for understanding hormone response in ILC cells, and review current data on these model systems. The promise for new insight into ILC, based on extensive representation of the disease in recent large scale genomic studies, is also discussed. Increasing understanding of endocrine response in ILC represents a critical area for future research to improve patient outcomes for this understudied breast cancer subtype.

Immunohistochemistry applied to the differential diagnosis between ductal and lobular carcinoma of the breast

The distinction between classic lobular and ductal carcinoma, both in situ and invasive, has important therapeutic and management implications. Most ductal and lobular carcinomas are distinguished readily on hematoxylin-eosin-stained sections because of distinct histomorphologic features. In cases with ambiguous morphologic features, however, categorization in one or another type can be a challenge. Several immunohistochemical markers, including epithelial cadherin, p120, β-catenin, and low-molecular-weight and high-molecular-weight cytokeratins among others, have been introduced to help better discriminate between lobular neoplasia and ductal carcinoma. In this critical review of the literature, we comment about the usefulness and the limitations of these markers to improve the accuracy in the differential diagnosis of breast pathology.

Clinical benefit from neoadjuvant chemotherapy in oestrogen receptor-positive invasive ductal and lobular carcinomas

Background:

The aim of this study was to compare clinical and pathological outcomes after neoadjuvant chemotherapy between oestrogen receptor (ER)-positive invasive pure lobular carcinoma (ILC) and invasive ductal carcinoma (IDC).

Methods:

This analysis included 1895 patients (n=177 ILC; n=1718 IDC), with stage I–III breast cancer, who received neoadjuvant chemotherapy. Clinical and pathological response rates, the frequency of positive surgical margins and rate of breast-conserving surgery were compared.

Results:

There was a trend for fewer good clinical responses in ILC compared with IDC. Tumour downstaging was significantly less frequent in ILC. Positive or close surgical resection margins were more frequent in ILC, and breast-conserving surgery was less common (P<0.001). These outcome differences remained significant in multivariate analysis, including tumour size, nodal status, age, grade and type of chemotherapy. Invasive pure lobular carcinoma was also associated with a significantly lower pathological complete response (pCR) rate in univariate analysis, but this was no longer significant after adjusting for tumour size and grade.

Conclusion:

Neoadjuvant chemotherapy results in lower rates of clinical benefit, including less downstaging, more positive margins and fewer breast-conserving surgeries in ER-positive ILC compared with ER-positive IDC. Pathological complete responses are rare in both groups, but do not significantly differ after adjusting for other variables.