The hormonal receptor status in breast cancer can be altered by neoadjuvant chemotherapy: a meta-analysis

Pathological Changes Following Neoadjuvant Endocrine Therapy (NAET): A Multicentre Study of 391 Breast Cancers

Oestrogen receptor (ER)-positive breast cancer (BC) is generally well responsive to endocrine therapy. Neoadjuvant endocrine therapy (NAET) is increasingly being used for downstaging ER-positive tumours. This study aims to analyse the effect of NAET on a well-characterised cohort of ER-positive BC with particular emphasis on receptor expression. This is a retrospective United Kingdom (UK) multicentre study of 391 patients who received NAET between October 2012 and October 2020. Detailed analyses of the paired pre- and post-NAET morphological changes and hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) expression were performed. The median duration of NAET was 86 days, with median survival and overall survival rates of 380 days and 93.4%, respectively. A total of 90.3% of cases achieved a pathological partial response, with a significantly higher rate of response in the HER2-low cancers. Following NAET, BC displayed some pathological changes involving the tumour stroma including central scarring and an increase in tumour infiltrating lymphocytes (TILs) and tumour cell morphology. Significant changes associated with the duration of NAET were observed in tumour grade (30.6% of cases), with downgrading identified in 19.3% of tumours (p < 0.001). The conversion of ER status from positive to low or negative was insignificant. The conversion of progesterone receptor (PR) and HER2 status to negative status was observed in 31.3% and 38.1% of cases, respectively (p < 0.001). HER2-low breast cancer decreased from 63% to 37% following NAET in the paired samples. Significant morphological and biomarker changes involving PR and HER2 expression occurred following NAET. The findings support biomarker testing on pre-treatment core biopsies and post-treatment residual carcinoma.

Does immunohistochemical marker conversion affect the prognosis in breast cancer patients receiving neoadjuvant chemotherapy?

Biomarkers such as hormone receptors (HR) and human epidermal growth factor receptor2 (HER2) may change after neoadjuvant chemotherapy (NAC) in breast cancer patients. The aim of this study was to investigate the rates of receptor change after NAC and to evaluate the prognostic impact of change. Patients with breast cancer who received NAC were included in the study. Changes in pathological findings (ER, PR, HER-2, Ki-67, grade) before and after NAC were examined. In addition, the effect of receptor exchange on prognosis was evaluated. Kaplan Meier analysis was used for survival analyses. Study was approved by Ethics Board of Tepecik Training and Research Hospital (Decision number 2021/10-02). We confirm that all methods were performed in accordance with relevant named guidelines and regulations. The study included 203 female patients. When pathological findings before and after NAC were compared, significant regression was found in grade and Ki-67 values (p = 0.003, p < 0.001). ER change rate was 11.8%, PR change rate was 24.6% and HER-2 change rate was 12.5%. No significant correlation was found between ER, PR and HER-2 changes and prognosis. The pathological T stage after NAC being 1 or 2, no lymph nodes detected, and the tumor grade being 1 or 2 were independent variables related to survival (p: 0.002, p: 0.014, p < 0.001). In patients with breast cancer, it would be appropriate to re-evaluate the HER-2 and HR status of the surgical specimen following NAC, especially in initially negative patients. The correlation of receptor discordance with prognosis is not clear and more extensive studies are needed.

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Comprehensive evaluation of the relationship between biomarker profiles and neoadjuvant chemotherapy outcomes for breast cancer patients

BACKGROUND

Accurately predicting the response to neoadjuvant chemotherapy (NAC) in breast cancer patients is crucial for guiding treatment strategies and enhancing clinical outcomes. Current studies have primarily focused on a limited set of biomarkers. More importantly, the results of many studies are in conflict. To address this, we conducted a comprehensive evaluation of the predictive value of a diverse range of clinically available molecular biomarkers in breast cancer, including HER2, ER, PR, TOPO II, EGFR, Ki67, CK5/6, AR, and p53. Additionally, we assessed changes in these biomarkers after NAC administration.

METHODS

Our study involved 189 patients with invasive breast cancer who underwent NAC at our institute. We examined biomarker profiles in core-needle biopsies taken before NAC and in surgical specimens obtained after NAC. We examined the association between these biomarkers and NAC outcomes, focusing on two main aspects: the rate of pathological complete response (pCR) and the reduction in tumor size. We used Chi-square and Mann-Whitney U tests to compare biomarker status changes between pCR and non-pCR patients. Linear regression analysis was employed to evaluate the relationship between biomarker status and tumor shrinkage rate. Additionally, we compared the expression status of these biomarkers before and after NAC using Chi-square and Wilcoxon signed-rank tests.

RESULTS AND CONCLUSIONS

Our results demonstrated significant differences in the expression levels of HER2, ER, PR, TOPO II, EGFR, and Ki67 between pCR and non-pCR patients, underscoring their potential as predictive markers for NAC outcomes. Importantly, our results have shed light on the contentious issue surrounding TOPO II in NAC outcome prediction. We have provided evidence that establishes a significantly positive association between TOPO II expression level and the pCR rate. Notably, tumor size was identified as a relevant predictive factor for achieving pCR. Regarding biomarker profiles, only Ki67 levels and TOPO II status exhibited changes following NAC, resolving previous controversies. While the ER and PR status remained unchanged, their expression values exhibited a slight but significant decrease post-NAC. Our results provide clarity and insights into the value and potential of using these biomarkers to predict NAC responses and prognosis in breast cancer patients.

Estrogen receptor-negative/progesterone receptor-positive breast cancer has distinct characteristics and pathologic complete response rate after neoadjuvant chemotherapy

PURPOSE

The status of hormone receptors (HR) is an independent factor affecting survival and chemotherapy sensitivity in breast cancer (BC) patients, with estrogen receptor (ER) and progesterone receptor (PR) having the most significant effects. The ER-/PR + phenotype has been controversial in BC, and experts will face many challenges in determining treatment strategies. Herein, we systematically analyzed the clinicopathological characteristics of the ER-/PR + phenotype in BC patients and the response to chemotherapy.

PATIENTS AND METHODS

We included two cohorts. The first cohort counted the relationship between clinicopathologic data and survival outcomes for 72,666 female patients in the Surveillance, Epidemiology, and End Results (SEER) database. The second cohort analyzed the relationship between clinicopathological data and pathologic complete response (pCR) rate in 879 patients at the Harbin Medical University Cancer Hospital. The classification data were compared by the chi-square test and Fister's exact test of the Logistic regression model, and predictor variables with P < 0.05 in the univariate analysis were included in the multivariate regression analysis. The Kaplan-Meier method evaluated breast cancer-specific survival (BCSS) and overall survival (OS) to investigate the relationship between different HR typing and survival and pCR.

RESULTS

In the two cohorts, 704 (0.9%) and 11 (1.3%) patients had the ER-/PR + phenotype, respectively. The clinicopathologic features of patients with the ER-/PR + phenotype are more similar to those of the ER-/PR- phenotype. The ER-/PR + phenotype is more common in younger and premenopausal women, and most ER-/PR + phenotypes exhibit higher histological grades. Survival analysis showed that there were significant differences in OS and BCSS among patients with different HR states (P < 0.001). The survival results of patients with the ER + /PR + phenotype were the best. The prognosis of the ER-/PR + phenotype was similar to that of the ER-/PR- phenotype. On the other hand, we found that HR status was also an independent predictor of post-NAC pCR rate in BC patients. The ER + /PR- and ER-/PR- phenotypes were more sensitive to chemotherapy than the ER + /PR + phenotypes.

CONCLUSION

HR status is the main factor affecting BC's survival outcome and pCR rate. Patients with the ER-/PR + phenotype possess more aggressive biological factors and can benefit significantly from chemotherapy. We need to pay more attention to this group and achieve individualized treatment, which will help us treat BC better and provide new targets and blueprints for our clinical treatment.

HER2 categorical changes after neoadjuvant chemotherapy: A study of 192 matched breast cancers with the inclusion of HER2-Low category

Understanding the changes of HER2 expression after neoadjuvant chemotherapy (NAC) in breast cancer (BC) is more important than ever, since it may allow more patients to access the effective therapeutic drugs targeting HER2-low BC. 192 matched pre- and post-NAC BCs were analyzed. HER2 immunohistochemistry (IHC) was re-evaluated with consensus according to the current ASCO/CAP guidelines. Tumors were categorized into HER2-0 (IHC0+), HER2-low (IHC1+ or IHC2+/ISH-) and HER2-positive (IHC3+ or IHC2+/ISH+) subgroups. 55 (28.6 %) patients achieved pathologic complete response (pCR). HER2-low BC accounted for 75/192 (39.1 %) baseline tumors, and 48/133 (36.1 %) residual tumors. In the non-pCR cohort, 53 (39.9 %) patients had HER2 categorical change after NAC, most commonly converting from HER2-low to HER2-0 (20.3 %, n = 27). Among patients with residual tumor, 25.6 % (11/43) of patients with baseline HER2-0 expression experienced a categorical change to HER2-low after NAC, significantly higher (p < 0.05) in the hormone receptor (HR) positive (9/23, 39.1 %) compared to the HR negative tumors (10 %, 2/20). Exploratory analysis failed to reveal a statistically significant difference in disease free survival and overall survival in non-pCR patients with or without HER2 change. Our results suggest that a substantial number of patients may experience HER2 categorical change after NAC, supporting re-testing of HER2 status in post-NAC residual tumors. Retesting HER2 status may be particularly important for evaluating post-NAC HER2-low status, in order to better assess which patients will more likely benefit from therapeutic drugs targeting HER2-low BC.

Clinical implications of receptor conversions in breast cancer patients who have undergone neoadjuvant chemotherapy

PURPOSE

In this study, we aimed to determine the incidence of receptor conversions after neoadjuvant chemotherapy (NAC) for breast cancer and assess the rate at which receptor conversion leads to changes in adjuvant therapy regimens.

METHODS

We performed a retrospective review of female breast cancer patients treated with NAC at an academic breast center between January 2017 and October 2021. Patients with residual disease on surgical pathology and complete receptor status information for both pre-NAC and post-NAC specimens were included. Incidence of receptor conversions, defined as a change in at least one hormone receptor (HR) or HER2 status compared to preoperative specimens, was tabulated, and adjuvant therapy modalities were reviewed. Factors associated with receptor conversion were analyzed using chi-square tests and a binary logistic regression.

RESULTS

Of the 240 patients with residual disease after NAC, 126 (52.5%) had receptor testing repeated. After NAC, 37 specimens (29%) had a receptor conversion. Receptor conversion resulted in the addition or removal of an adjuvant therapy in 8 patients (6%), indicating a number needed to screen of 16. Prior history of cancer, receipt of initial biopsy at an outside site, HR-positive tumors, and a pathologic stage of II or lower were factors associated with receptor conversions.

CONCLUSION

HR and HER2 expression profiles frequently change after NAC and drive adjustments in adjuvant therapy regimens. Repeat testing of HR and HER2 expression should be considered in patients who receive NAC, especially in patients with early stage, HR-positive tumors whose initial biopsies were performed externally.

The changes of subtype markers between first and second primary breast cancers

BACKGROUND

Previous studies investigated the changes of subtype markers [estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2)] in several clinical settings, but not for second primary breast cancer (SPBC) after first primary breast cancer (FPBC).

METHODS

A total of 15,390 patients with SPBC were preliminarily selected from the Surveillance, Epidemiology, and End Results Program, and 3777 patients with complete information on three subtype markers in both FPBC and SPBC were included in the final analyses. The changes of subtype markers and their prognostic implications and potential influential factors were well investigated.

RESULTS

The overall change rates of ER, PR, and HER2 between FPBC and SPBC were 23.0% (867/3777), 35.0% (1322/3777), and 18.3% (691/3777), respectively. Gains of ER, PR, and HER2 after negative index markers were 48.7% (364/748), 37.9% (418/1103), and 11.5% (370/3211), while losses of markers after positive index markers were 16.6% (503/3029), 33.8%(904/2674), and 56.7%(321/566). Loss of ER was significantly associated with increased mortality (18.1% vs. 7.9%, p < 0.001), while gain of ER was significantly associated with decreased mortality (11.5% vs. 23.2%, p < 0.001). Similar results were observed for changes of PR status. However, loss of HER2 was significantly associated with decreased mortality (8.7% vs. 16.3%, p = 0.014), and no significant association was observed between the gain of HER2 and the prognosis of SPBC. Multivariate competing risk analyses showed similar results. HER2 status in FPBC, chemotherapy, and radiotherapy was significantly associated with changes of ER/PR (all p < 0.05), and no available therapies associated with HER2 change.

CONCLUSION

The changes of subtype markers are observed in a considerable proportion of patients and has statistically significant prognostic implications. Biopsies should be taken as a routine procedure for better therapy management.

Clinical significance and prognostic value of receptor conversion after neoadjuvant chemotherapy in breast cancer patients

The hormone receptor (HR) status and human epidermal growth hormone receptor 2 (HER2) status of patients with breast cancer may change following neoadjuvant chemotherapy (NAC). We retrospectively analyzed the clinical data of 294 patients with stage II/III breast cancer to evaluate the clinical significance and prognostic value of receptor transformation after NAC in breast cancer patients. Pathological complete response after NAC was achieved in 10.7% of patients. HR, estrogen receptor (ER), progesterone receptor (PR), HER2, and Ki-67 conversion rates were 9.2%, 6.5%, 13.0%, 4.4%, and 33.7%, respectively. Patients with stable HR (P = 0.01) and HER2 (P = 0.048) expression had more favorable overall survival (OS). Low or reduced Ki-67 expression was associated with better disease-free survival (DFS) (P < 0.001) and OS (P < 0.01). Multivariate analysis showed that the number of lymph nodes after NAC, HR conversion, and radiotherapy were independent prognostic factors for overall survival. HR conversion implied a higher risk of death [hazard ratio, 2.56 (95% confidence interval: 1.19-5.51); P = 0.016]. Patients with HR conversion after NAC who received endocrine therapy had better DFS (P = 0.674) and OS (P = 0.363) than those who did not receive endocrine therapy, even if the HR changed from positive to negative. In conclusion, pathological testing should be performed before and after NAC, and even patients with HR conversion after NAC might benefit from endocrine therapy.

Association of serum reproductive hormones changes after neoadjuvant chemotherapy with hormone receptors expression alterations and survival outcomes in breast cancer

Purpose

This study aimed to determine the effect of neoadjuvant chemotherapy (NAC) on circulating levels of reproductive hormones and evaluate the correlation of hormone changes after NAC with hormone receptors expression alterations and relapse-free survival (RFS) outcomes in breast cancer.

Methods

Information from 181 breast cancer patients who received NAC was retrospectively analyzed. For hormones parameters, the median and interquartile range (IQR) were provided at baseline and the end of NAC then was compared by Wilcoxon signed-rank test. Categorical variables were represented as numbers and percentages and were compared via two-sided chi-square and Fisher's tests. The RFS outcomes were compared between patients according to hormone changes using the log-rank test. Univariate and multivariate survival analyses with hazard ratios (HR) and 95% confidence intervals (95% CI) were carried out using Cox regression.

Results

Sex steroids including estradiol, progesterone, testosterone, and dehydroepiandrosterone sulfate (DHEAS) levels decreased significantly after NAC among both premenopausal and postmenopausal patients (all P < 0.05). Decreased estradiol levels were associated with reduced progesterone receptor (PR) expression (P = 0.030). In multivariate survival analysis, the non-decreased progesterone level was strongly associated with worse RFS (non-decreased vs. decreased, HR = 7.178, 95% CI 2.340–22.019, P = 0.001). Patients with decreased progesterone levels exhibited better 3-year RFS compared with those with non-decreased (87.6% vs. 58.3%, log-rank, P = 0.001).

Conclusion

Multiple reproductive hormone levels were influenced by NAC. The change in estradiol level had a positive connection with PR expression alteration. Furthermore, an inverse association between the change in progesterone level and RFS outcomes was found. These findings may provide a theoretical basis for pre-operative endocrine therapy combined with NAC in breast cancer patients.

Receptor Status after Neoadjuvant Therapy of Breast Cancer: Significance and Implications

Neoadjuvant chemotherapy (NACT) is now established in routine management of early breast cancer. Alterations in oestrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) following NACT are reported, with wide variation in results across series. In larger series, changes in ER status are identified in 5-23%, whilst changes in PR status are more frequent (14.5-67%). HER2 status changes less frequently with loss being more common than gain, and higher rates of change with immunohistochemistry are observed compared to in situ hybridization and following HER2-targeted therapy compared with chemotherapy alone. Triple negative is the most stable molecular subtype with combined ER, and HER2-positive cancers show the highest rate of change. Neoadjuvant endocrine therapy is used less commonly than NACT, and whilst loss of ER is rare, changes in PR status can occur in up to 40% of cases. There is relatively little published data on the impact of change in receptor status on survival outcomes. In patients whose tumours become ER or HER2 positive post-NACT, endocrine or anti-HER2 therapy can be initiated, although evidence from clinical trials is lacking. Most guidelines do not currently recommend routine retesting; however it should be considered in some circumstances.

Biomarker dynamics and prognosis in breast cancer after neoadjuvant chemotherapy

Breast cancer is a biologically diverse disease with treatment modalities selected based on tumor stage and tumor biology. Distinct intrinsic subtypes and surrogate biomarker profiles play a major role for therapeutic decisions. Response rates to systemic and local treatments as well as the interaction with epidemiological risk factors have been validated in clinical trials and translational studies. This retrospective study addresses the question how biomarker profiles and treatment modalities in the neoadjuvant chemotherapy setting have changed during the past 15 years and what prognostic impact these changes implicate. 342 female breast cancer stage I-IV patients receiving neoadjuvant chemotherapy between 2003 and 2017 were analyzed. Overall survival (OS) was correlated with preoperative clinical stage, postoperative pathological stage, treatment modalities and tumor biology before and after chemotherapy. Two subgroups were separated using an arbitrary cut-off year at 2009/2010, due to 2010 when platinum containing regimens were first administered. Median follow-up was 54 months. 57 (17%) patients died; recurrences occurred in 103 of 342 (30%) patients. Nodal stage and intrinsic subtypes (pre- and postoperative) significantly correlated with OS (p < 0.001). Preoperative histological grading lacked prognostic power. When comparing the patient characteristics of the subgroups, we found significant difference in the following characteristics: cT, ypT, ypN, pCR and chemotherapy regimens (p < 0.001). There was no difference in OS when comparing the two subgroups. Pathological complete response (pCR) rates had a significant impact on OS and disease-free survival (DFS) in HER2+ and triple negative subtypes (p = 0.03). In multivariate analysis, high proliferation index (> 30%), clinical metastatic stage and pathological tumor stage had prognostic impact on OS (p < 0.001, p = 0.0001, p = 0.002). Clinico-pathological factors and distinct therapy regiments especially in triple negative and HER2+ subtypes have prognostic impact on pCR, OS and DFS after neoadjuvant chemotherapy.

Pathologic evaluation of specimens after neoadjuvant chemotherapy in breast cancer: Current recommendations and challenges

Neoadjuvant chemotherapy is increasingly used to optimize breast conservation surgery and is becoming a standard of care in a subset of breast cancer patients. An accurate pathologic assessment is crucial in guiding clinical decisions and subsequent management and prognosis. This review aims to summarize the most current literature, recommendations, and challenges in the pathologic evaluation of breast cancer after neoadjuvant chemotherapy. Included are the most current definitions of the different types of tumor response, the underlying factors that can affect tumor response, how to assess lymph nodes, margins, and tumor markers post-neoadjuvant chemotherapy, as well as the different classification systems a pathologist can use to assess residual disease. In this era of de-escalation of surgical treatment, studies on imaging techniques to assess residual disease and avoid surgery after neoadjuvant chemotherapy have also been done. However, at least for now, surgical treatment remains the preferred practice. As such, pathologists play an increasingly critical role in standardizing assessment of residual disease post-neoadjuvant chemotherapy, and in optimizing the knowledge gained by this approach to breast cancer therapy.

The Effect of Chemotherapy on Estradiol Levels in Patients with HER 2-Overexpression Breast Cancer in Dr Moewardi General Hospital, Surakarta, Indonesia

AIM: This study aims to evaluate the effect of adjuvant chemotherapy on estradiol levels in patients with HER 2-overexpression breast cancer in a developing country. METHODS: This comparative study with pre- and post-design model observation approach, involving patients with HER 2-overexpression breast cancer who had undergone surgery and had never received chemotherapy or hormonal therapy before, who were then given adjuvant chemotherapy. Estradiol levels were measured before and after chemotherapy. The study was carried out in the surgical oncology division of RSUD Dr. Moewardi (RSDM) Surakarta from January 2020-December 2020. Descriptive data are presented in a frequency table based on age, menstrual status, parity status, breastfeeding status, contraception, contraception duration, family history, stage, and histological grade. Before and after chemotherapy in patients with breast cancer, the estradiol levels employed the paired sample t-test of the Wilcoxon rank test because the data did not meet the normality assumption. RESULTS: From the total data of 21 patients, 15 patients experienced a decrease in estradiol levels after chemotherapy, while six patients underwent an increase. The mean estradiol level before chemotherapy was 89.41 pg/ml, whereas the mean estradiol level after chemotherapy was 55.90 pg/ml. It indicates a difference in the decrease in estradiol levels of 33.51 pg/ml. The statistical test results also obtained a p-value of = 0.033 (p < 0.05), which signifies a significant difference between estradiol levels before and after chemotherapy. Thus, chemotherapy is effective in lowering estradiol levels in patients with breast cancer. CONCLUSION: Chemotherapy affects decreasing estradiol levels in patients with HER2 overexpression breast cancer.

Concordance Between ER, PR, HER2 neu Receptors Before and After Neoadjuvant Chemotherapy in Locally Advanced Breast Cancer

Background

Introducing neoadjuvant chemotherapy (NCT) in a breast cancer patient may be associated with changes in estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth hormone receptor 2 (HER2) status.

Method

In our prospective cohort study, we evaluated the impact of change in estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth hormone receptor 2 (HER2) on the prognosis of breast cancer patients treated with neoadjuvant chemotherapy (NCT). We investigated 110 patients with locally advanced breast cancer for ER, PR and HER2 status of their lesions before and after NCT.

Result

For hormone receptor status (HR) (which include ER, PR) of the residual tumor of the patients after receiving NCT, 12 (10.9%) of them changed from HR (+) to HR (−) and 15 (13.6%) changed from HR (−) to HR (+). For HER2 status after NCT, 8 (7.3%) patients changed from HER2 (+) to HER2 (−) and 9 (8.2%) patients changed from HER2 (−) to HER2 (+). Triple negative (TN) tumor phenotype changes occurred in 17 (15.5%) patients. Patients for whom the HR status changed from positive to negative had poor prognosis for both disease-free survival (DFS) and overall survival (OS) in univariate survival analysis.

Conclusion

Changes in ER, PR, HER2 status and tumor phenotype in breast cancer patients after NCT had a negative prognostic impact and were associated with a poor prognosis.

Prognostic significance of estrogen, progesterone and HER2 receptors' status conversion following neoadjuvant chemotherapy in patients with locally advanced breast cancer: Results from a tertiary Cancer Center in Saudi Arabia

Background

The prognostic impact of neoadjuvant chemotherapy (NAC) on the receptor expression status in patients with locally advanced breast cancer (LABC) is still not fully understood. We aimed to evaluate the changes in hormone (estrogen and progesterone) receptor (HR) and human epidermal growth factor receptor 2 (HER2) status post-NAC and their correlation with survival.

Methods

Patients with LABC who have received NAC between 2008 and 2015 and have been followed up till December 2019 at the Oncology Center, King Saud University, KSA were analyzed retrospectively. biomarker analysis of ER, PR & HER2 were done using immunohistochemistry (IHC) and Fluorescent in situ hybridization.

Results

Ninety-one patients fulfilled the inclusion criteria. HR status changed in 21(23.1%) patients, with a significant difference between patients with stable receptors and those with any receptor conversion; p = 0.000. Five (5.5%) initially HER2 negative tumors became HER2 positive and 10 (11%) initially HER2 positive tumors became HER2 negative after NAC. The difference in HER2 expression level before and after NAC was not statistically significant (p = 0.302). Univariate analysis relating patients’ characteristics and 10-years disease-free survival (DFS) showed only significant correlations with the expressions of ER, PR, and any receptor conversion, (ER and/or PR) p< 0.001, p< 0.001, and p = 0.001; respectively. In the univariate analysis, none of the clinicopathological features showed a significant correlation with the OS except for the molecular subtypes P<0.001.

Conclusions

Patients with LABC have significant changes in the ER and PR receptor status following NAC. Post-NAC expressions change of ER and PR (ER and/or PR) are correlated to DFS. Retesting of the hormone receptors should be considered after NAC in Saudi patients with LABC.

Impact of immunohistochemical profile changes following neoadjuvant therapy in the treatment of breast cancer

Introduction

Currently, the indication for neoadjuvant chemotherapy is increasing in the treatment of breast cancer. Variability in the expression of biomarkers following neoadjuvant treatment has been observed, which could be accompanied by changes in the adjuvant treatment.

Objectives

The primary objective was to evaluate the variability of biomarkers prior to and following neoadjuvant therapy. Secondary objectives were to determine which tumour subtype (as determined by immunohistochemical markers) most frequently achieved pathological complete response (pCR); whether the biomarker variation resulted in a change in immunophenotype and subsequently modification to the adjuvant treatment.

Materials and methods

A retrospective observational analysis was carried out on patients with a diagnosis of breast cancer who had neoadjuvant therapy prior to surgery in the Breast Care Service of the Buenos Aires British Hospital between January 2009 and June 2020.

Results

One hundred and seventy-two patients were included. The pCR rate was 28.5%. The tumour immunophenotype that achieved pCR most frequently was the hormone receptor negative /HER2+ group with a value of 85.2%. The analysis was carried out on the 123 patients with residual disease. The observed variability for oestrogen receptors (ER) was 8.9%, for progesterone receptors (PR), 29.9% and for HER2, 13.8%. These changes were statistically significant. There were changes to the tumour immunophenotype in 26 cases (21.1%) with modifications to the adjuvant treatment in nine of these (34.6%; 7.3% of all tumours with residual disease).

Conclusions

In this study, we observed statistically significant variability in the expression of ER, PR and HER2 prior to and following neoadjuvant treatment, which identified modifications in the tumour immunophenotype in 21.1%, and changes to the adjuvant treatment in 7.3% of all tumours with residual disease, justifying the re-assay of biomarkers in the surgical specimen.

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

CONTEXT.—

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

OBJECTIVE.—

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

DESIGN.—

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

RESULTS.—

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

CONCLUSIONS.—

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

Pathologic reporting practices for breast cancer specimens after neoadjuvant chemotherapy-a survey of pathologists in academic institutions across the United States

Neoadjuvant chemotherapy is increasingly being used to treat primary invasive breast carcinoma. Response to neoadjuvant chemotherapy is an important determinant of prognosis. A multidisciplinary group published recommendations for standardization of pathologic reporting of postneoadjuvant chemotherapy specimens. Based on these recommendations, we sent a survey to 26 pathologists currently practicing breast pathology in academic centers across the United States. The survey consisted of six questions with yes/no answers. The pathologists were encouraged to add comments. We received responses from 23 breast pathologists from 19 centers. The questions and responses were as follows: 1. Do you grade tumors after neoadjuvant chemotherapy?-17 (74%) responded yes and 6 (26%) responded no. 2. Do you routinely repeat hormone receptors, HER2/Neu results after neoadjuvant chemotherapy?-15 (65%) responded yes and 8 (35%) responded no. 3. If there are features of tumor regression/tumor bed at the margin but no actual tumor at the margin do you report this?-11 (48%) responded yes and 8 (35%) responded no and 4 (17%) reported a variable practice. 4. Do you report number of nodes with fibrosis/changes of regression?-17 (74%) responded yes and 6 (26%) responded no. 5. Do you report residual cancer burden score on your report or at least provide information on your report so clinicians can calculate residual cancer burden?-17 (74%) responded yes and 6 (26%) responded no. 6. Do you have a specific synoptic for cases after neoadjuvant chemotherapy?-5 (22%) responded yes and 18 (78%) responded no. The major reasons provided for nonadherence to recommended guidelines included pathologists were unaware of prognostic importance of providing the information, reporting practices were clinician driven and some pathologists were unaware of the recommendation. We document that academic breast pathology practices show significant variability in reporting of postneoadjuvant chemotherapy cases. We document barriers to standard practice and provide recommendations we hope will contribute to a more uniform reporting practice for these complex specimens.

HER2 status in breast cancer: changes in guidelines and complicating factors for interpretation

Human epidermal growth factor receptor 2 (HER2) protein overexpression and/or HER2 gene amplification is found in about 20% of invasive breast cancers. It is a sole predictive marker for treatment benefits from HER2 targeted therapy and thus, HER2 testing is a routine practice for newly diagnosed breast cancer in pathology. Currently, HER2 immunohistochemistry (IHC) is used for a screening test, and in situ hybridization is used as a confirmation test for HER2 IHC equivocal cases. Since the American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines on HER2 testing was first released in 2007, it has been updated to provide clear instructions for HER2 testing and accurate determination of HER2 status in breast cancer. During HER2 interpretation, some pitfalls such as intratumoral HER2 heterogeneity and increase in chromosome enumeration probe 17 signals may lead to inaccurate assessment of HER2 status. Moreover, HER2 status can be altered after neoadjuvant chemotherapy or during metastatic progression, due to biologic or methodologic issues. This review addresses recent updates of ASCO/CAP guidelines and factors complicating in the interpretation of HER2 status in breast cancers.

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

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

Prognostic value of receptor status conversion following neoadjuvant chemotherapy in breast cancer patients: a systematic review and meta-analysis

Biomarkers of breast cancer such as hormone receptors (HR) and human epidermal growth factor 2 (HER2) can be altered after neoadjuvant chemotherapy (NAC). However, whether the conversion of these receptors affects the prognosis of patients remains to be determined. We sought to evaluate the prognostic value of HR and HER2 receptors before and after NAC and to analyze their clinical implications. Relevant studies were used to calculate the pooled hazard ratios, 95% confidence interval (95% CI). This meta-analysis included eight studies with 2847 patients. Compared to patients with HR+ → +, patients with HR+ → - have shorter disease free survival (DFS) (hazard ratio = 2.64, 95% CI 1.86-3.75) and overall survival (OS) (hazard ratio = 2.99, 95% CI 1.97-4.54). Furthermore, patients with HR- → + tend to achieve better DFS (hazard ratio = 0.83, 95% CI 0.60-1.17) compared to patients with HR- → -. Patients with HR- → + gain better OS (hazard ratio = 0.67, 95% CI 0.46-0.99) compared to patients exhibiting HR- → -. When comparing patients with HER2+ → - to patients with HER2+ → +, patients with HER2+ → - tended to achieve better DFS (hazard ratio = 1.65, 95% CI 1.08-2.53) though results for OS (hazard ratio = 1.16, 95% CI 0.54-2.49) were not statistically significant. Our data strongly support the need for redetection of HR and HER2 receptor status of surgical sample following neoadjuvant therapy. Changes in HR status induced by NAC can be used as a prognostic factor in breast cancer patients for predicting both OS and DFS. HER2 change may also be valuable for predicting prognosis. Further research should explore therapeutic strategies for those presenting receptor status conversion.

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.

Conversion of immunohistochemical markers and breast density are associated with pathological response and prognosis in very young breast cancer patients who fail to achieve a pathological complete response after neoadjuvant chemotherapy

Purpose

Patients younger than age 35 that fail to achieve a pathologic complete response (pCR) after Neoadjuvant chemotherapy (NACT) tend to have worse long term outcomes. The purpose of our study was to assess the correlation between the conversion of immunohistochemical (IHC) markers and breast density and investigate their association with pathological response and prognosis.

Methods

We included 119 patients younger than age 35 who failed to achieve a pCR after NACT in this analysis. We evaluated the clinical and pathological response to NACT by the Union for International Cancer control (UICC) and the Miller-Payne grading (MPG) systems, respectively. A breast density assessment was applied via mammography examination at the time of diagnosis. MPG and breast density (BD) have been combined to define a specific classification of three risk levels to evaluate the prognosis of these patients.

Results

The diameter changes of the tumors and lymph nodes were negatively associated with hormone receptor conversion and positively correlated with Ki67 conversion. A significantly large size change was observed in the groups demonstrating conversion from HER-2 (+) to (−). The variation level of IHC markers was related to MPG and BD and was associated with the survival rate of the patients. Patients with a high breast density and low Miller-Payne grading after NACT had a higher risk of distant metastases or local recurrences.

Conclusion

ER, PR and Ki67 conversion are closely related to MPG, while PR and Ki67 conversion are closely related to BD. While ER and PR conversion are independent and significant predictors of disease free survival (DFS) and overall survival (OS), HER-2 and Ki67 conversion are only significant for DFS. This risk factor grouping provides a useful index to evaluate the risk of young women with breast cancer who fail to achieve a pCR.

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

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

Clinical significance and prognostic value of receptor conversion in hormone receptor positive breast cancers after neoadjuvant chemotherapy

Background

Neoadjuvant chemotherapy (NAC) is widely used in advanced breast cancer patients. However, there is little known about conversion frequency of estrogen receptor (ER) and/or progesterone receptor (PR) status for hormone receptor positive-breast cancer patients after NAC and their correlation with prognosis.

Methods

In this study, 231 breast cancer patients with residual disease after NAC were enrolled and divided into receptor stable group (having no conversion in both ER and PR status pre- and post-NAC) and any receptor conversion group (having any conversion in either ER or PR status). Univariate and multivariate survival analyses were used to compare survival differences between the two groups.

Results

Fifty-five patients (23.8%) had ER and/or PR conversion after NAC. Younger patients (≤ 50 years) were more likely to have receptor conversion (P = 0.014). For 213 patients (92.2%) who received adjuvant endocrinotherapy after surgery, the 5-year disease free survival (DFS) estimates for patients in the any receptor conversion group (55.2%) was worse than patients in the receptor stable group (73.7%, Log-rank test, P = 0.015). While the 5-year overall survival estimates for patients with or without receptor conversion were not statistically different (86.0 vs. 82.4%, Log-rank test, P = 0.587). In multivariate Cox proportional hazard analyses, patients with any receptor conversion had worse DFS (hazard ratio, 1.995; 95% confidence interval, 1.130–3.521, P = 0.031).

Conclusions

It is necessary to recommend patients to test biomarkers in residual disease and pay more attention to patients who have any receptor conversion. These patients may need more individual therapy after surgery.

Negative Conversion of Progesterone Receptor Status after Primary Systemic Therapy Is Associated with Poor Clinical Outcome in Patients with Breast Cancer

Purpose

Alteration of biomarker status after primary systemic therapy (PST) is occasionally found in breast cancer. This study was conducted to clarify the clinical implications of change of biomarker status in breast cancer patients treated with PST.

Materials and Methods

The pre-chemotherapeutic biopsy and post-chemotherapeutic resection specimens of 442 breast cancer patients who had residual disease after PST were included in this study. The association between changes of biomarker status after PST and clinicopathologic features of tumors, and survival of the patients, were analyzed.

Results

Estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) status changed after PST in 18 (4.1%), 80 (18.1%), and 15 (3.4%) patients,respectively. ER and PR mainly underwent positive to negative conversion,whereas HER2 status underwent negative to positive conversion. Negative conversion of ER and PR status after PST was associated with reduced disease-free survival. Moreover, a decline in the Allred score for PR in post-PST specimens was significantly associated with poor clinical outcome of the patients. HER2 change did not have prognostic significance. In multivariate analyses, negative PR status after PST was found to be an independent adverse prognostic factor in the whole patient group, in the adjuvant endocrine therapy-treated subgroup, and also in pre-PST PR positive subgroup.

Conclusion

ER and HER2 status changed little after PST, whereas PR status changed significantly. In particular, negative conversion of PR status was revealed as a poor prognostic indicator, suggesting that re-evaluation of basic biomarkers is mandatory in breast cancer after PST for proper management and prognostication of patients.

The ever-evolving role of pathologists in the management of breast cancer with neoadjuvant treatment: recommendations based on the Spanish clinical experience

PURPOSE

To compare the current international standards for neoadjuvant systemic therapy (NAST) protocols, and establish consensus recommendations by Spanish breast pathologists; and to look into the Spanish reality of defining pathological complete response in daily practice.

MATERIALS AND METHODS

A modified Delphi technique was used to gain consensus among a panel of 46 experts with regard to important issues about NAST specimens, with the objective of standardize handling and analysis of these breast cancer specimens. In addition, a survey was conducted among 174 pathologists to explore the Spanish reality of post-NAST breast cancer specimens handling.

RESULTS

Our survey shows that pathologists in Spain follow the same guidelines as their international colleagues and face the same problems and controversies. Among the experts, 94.1% agreed on the recommendation for a pre-treatment evaluation with a core needle biopsy, and 100% of experts agreed on the need of having properly indicated information for the post-NAST surgical specimens. However, only 82.7% of them receive properly labelled specimens and even less receive specimens where markers are identified and the degree of clinical/radiological response is mentioned. Among participants 59.9% were familiar with the residual cancer burden system for post-NAST response quantification, but only 16.1% used it regularly.

CONCLUSIONS

Active participation on breast cancer multidisciplinary teams, optimal usage of core needle biopsy for timely and standardized procedures for the diagnostic analysis, and accurate diagnosis of pathological complete response and complete evaluation of the response to NAST need to become the standard practice when handling breast cancer specimens in Spain.

Adding Adjuvant Systemic Treatment after Neoadjuvant Therapy in Breast Cancer: Review of the Data

PURPOSE OF REVIEW

Residual disease after neoadjuvant chemotherapy is a poor prognostic factor; however, proven strategies to reduce recurrence risk and improve overall survival in this patient population are limited. Previous studies of residual disease have illustrated the importance of tumor intrinsic subtypes in treatment response and mechanisms of resistance. This review summarizes the rationale for various therapeutic approaches as well as completed and ongoing clinical trials for this high-risk group of patients.

RECENT FINDINGS

Regimens utilizing additional chemotherapy and targeted therapies (such as PARP inhibitors or bisphosphonates) have met with limited efficacy. Notably, a recently published randomized study of capecitabine in patients with residual disease demonstrated an improvement in disease-free survival and overall survival. While the results for capecitabine are promising, particularly for patients with triple-negative disease, the generalizability of these findings is an open question. Meanwhile, ongoing trials with novel agents that target specific tumor subtypes and the biology of residual disease may improve outcomes for other patient populations.

Natural History of Invasive Papillary Breast Carcinoma Followed for 10 Years: A Case Report and Literature Review

Diachronic research on untreated breast cancer completely depends on past medical records when no more recent, advanced methods are available. Herein, we report a case of invasive papillary breast carcinoma followed for 10 years in a 59-year-old woman who refused any treatment. The diagnosis was based on core needle biopsies. At the patient's first visit in July 2006, the tumor measured 10.4 × 7.2 × 3.5 cm. It was staged as IIIB (T4bN1). In May 2016, the tumor was staged as IIIC (T4bN3a). In the past 10 years, the tumor has increased to 12.1 × 9.0 × 4.2 cm. However, a whole-body bone scan and ¹⁸F-FDG PET/CT showed no evidence of distant metastasis. Immunohistochemistry results, corresponding to biopsies taken at subsequent examinations, have remained unaltered since 2006. The tumor was estrogen/progesterone receptor-positive and C-erbB2 expression was not detected. The Ki-67 labeling index was around 10%.

Histopathological tumour viability after neoadjuvant chemotherapy influences survival in resected pancreatic cancer: analysis of early outcome data

BACKGROUND

Neoadjuvant therapy is increasingly recognized as an effective strategy prior to pancreatoduodenectomy. We investigate the role of neoadjuvant chemotherapy (NAC) followed by surgery and the predictive role of viable residual tumour cells histopathologically on outcomes.

METHODS

The study population comprised of 195 consecutive patients with pancreatic adenocarcinoma who were treated with either NAC or a surgery-first (SF) strategy. Histopathological viable tumour cells were examined in the NAC patients and clinicopathological factors were correlated with overall survival.

RESULTS

Forty-two patients (22%) were treated with NAC and 153 patients (78%) underwent SF. NAC was associated with higher estimated blood loss during surgery (928 mL versus 615 mL; P = 0.004), fewer (<15) excised lymph nodes (37% versus 17%; P = 0.015) and lower rates of lymphovascular invasion (65% versus 45%; P = 0.044) when compared with SF. Two-year survival of patients undergoing NAC was 63% and 51% in patients undergoing SF (P = 0.048). The 2-year survival of patients who had >65% residual tumour cells was 45% and 90% in patients who had <65% residual tumour cells (P = 0.022). Favourable responders (<65% viable tumour cells) were observed to have shorter operation time (<420 min) (55% versus 13%; P = 0.038), trend towards negative lymph node status (38% versus 10%; P = 0.067) and greater lymph node harvest in node positive patients (≥4 positive lymph nodes) (77% versus 37%; P = 0.045).

CONCLUSION

The improved survival of patients undergoing NAC indicates effective management of micrometastatic disease and is an effective option requiring further investigation. Histopathological viable tumour cells after NAC was a surrogate marker for survival.

Alterations of biomarker profiles after neoadjuvant chemotherapy in breast cancer: tumor heterogeneity should be taken into consideration

Tumor biomarkers including estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and Ki-67 are routinely tested in breast cancer patients and their status guides clinical management and predicts prognosis. A few retrospective studies have suggested that neoadjuvant chemotherapy (NAC) in breast cancer may change the status of biomarker expression, which in turn will affect further management of these patients. In this study we take advantage of a relatively large cohort and aim to study the effect of NAC on biomarker expression and explore the impact of tumor size and lymph node involvement on biomarker status changes. We collected 107 patients with invasive breast cancer who received at least three cycles of NAC. We retrospectively performed and scored the immunohistochemistry (IHC) of ER, PR, HER2 and Ki-67 using both the diagnostic core biopsies before NAC and excisional specimens following NAC. HER2 gene status was assessed by fluorescence in situ hybridization for cases with IHC result of 2+. We demonstrated that there was a significant decrease in expression of PR (P = 0.013) and Ki-67 (P = 0.000) in post-NAC specimens compared to pre-NAC core biopsies. In addition, cases with large tumor size (≥2cm) and cases with lymph node metastasis were more frequently to have biomarker changes. Finally we studied cases with HER2 status changes after NAC treatments in detail and emphasized the nature of tumor heterogeneity.

Modern therapies and iatrogenic changes in breast pathology

Iatrogenic changes within the breast can provide challenges for the histopathologist in routine practice. Diagnostic procedures, such as core biopsies, result in reactive changes and can cause displacement of benign and malignant cells, the interpretation of which may cause difficulties in the resection specimen. Breast augmentation surgery with implants or injection of fillers, performed for cosmetic reasons or as part of a reconstructive process following removal of breast cancer, also produces reactive changes locally and at distant sites that may mimic cancer. The entity of implant-associated anaplastic large-cell lymphoma is now well recognized, with progress in our understanding of the underlying biological factors that drive its development. Chemotherapy and radiotherapy used in the treatment of breast cancer causes characteristic changes in normal breast tissue, and can alter the histological appearance and receptor status of the tumour. Radiotherapy to the breast, for breast cancer or childhood malignancies, increases the risk of developing a secondary malignancy in the breast long after treatment. In this review, we describe some of the iatrogenic changes that may be seen in histological specimens from the breast.

Weekly paclitaxel plus carboplatin with or without trastuzumab as neoadjuvant chemotherapy for HER2-positive breast cancer: loss of HER2 amplification and its impact on response and prognosis

PURPOSE

Neoadjuvant chemotherapy (NCT) plus anti-HER2 agents are the standard of care for locally advanced HER2-positive breast cancer. The aim of this study was to evaluate the prevalence and prognostic impact of HER2 loss in patients with HER2-positive disease treated with neoadjuvant therapy with or without trastuzumab.

METHODS

549 consecutive HER2-positive patients were included in this study. 379 patients were treated with paclitaxel, carboplatin, and trastuzumab (PCH cohort) and 170 were treated with paclitaxel and carboplatin only (PC cohort). Conversion of biomarkers before and after NCT was evaluated via immunohistochemistry (IHC) test. Cox regression model was used to investigate prognostic markers to relapse-free survival (RFS).

RESULTS

50.9% patients were considered as pCR responder in PCH cohort, whereas only 25.9% of patients experienced pCR in PC cohort (P < 0.001). HER2 loss were more frequently shown in PCH cohort with a proportion of 19.8%, compared to 9.4% in PC cohort (P = 0.009). In PCH cohort, patients with a loss of HER2 expression tended to have a higher risk of relapse compared to patients with maintained HER2 expression (HR = 2.639, 95% CI 1.103-6.311, P = 0.029). However, it did not correlate to patient outcome in the PC cohort (P = 0.296). Loss of HER2 was also correlated to ER conversion in PCH cohort.

CONCLUSION

Our study has provided new evidence that anti-HER2 treatment has a significant impact on HER2 loss. Far more importantly, the loss of HER2 amplification could identify non-pCR patients with high risk of disease relapse, which might help in tailoring following systemic treatment.

Prognostic value of receptor conversion after neoadjuvant chemotherapy in breast cancer patients: a prospective observational study

The hormone receptor (HR) status and human epidermal growth hormone receptor 2 (HER2) status of patients with breast cancer may change following neoadjuvant chemotherapy (NCT). This prospective observational study aimed to evaluate the prognostic impact of receptor conversion in breast cancer patients treated with NCT.Of the 423 consecutive patients who had residual disease in the breast after NCT, 55 (13.0%) changed from HR (+) to HR (-), 23 (5.4%) changed from HR (-) to HR (+), 27 (6.4%) changed from HER2 (+) to HER2 (-), and 13 (3.1%) changed from HER2 (-) to HER2 (+). A total of 54 (12.8%) changed to the triple-negative (TN) tumor phenotype. The loss of HR positivity was an independent prognostic factor for worse disease-free survival (DFS) and worse overall survival (OS) in multivariate survival analysis. Furthermore, the switch to the TN phenotype after NCT was another independent prognostic factor for worse survival for both DFS and OS. In conclusion, patients with breast cancer may experience changes in HR status, HER2 status and tumor phenotype after NCT. The loss of HR positivity and the switch to the TN phenotype after NCT were associated with a worse patient outcome.

Improving and extending the McNemar test using the Bayesian method

The well-known McNemar test assesses the difference between two correlated proportions in binary matched-pairs data. To improve the power of the McNemar test and extend it to related problems, we reinterpret the test in a Bayesian framework. Replacing the prior density by a more realistic one realizes a powerful test. We numerically investigate different choices of the prior density, which strongly affects the performance of the derived test. Furthermore, we compare the maximum actual levels of the proposed test with those of existing tests. The proposed test is advantageous for its wide extendibility. We combine the evidence from multiple strata by an approach that largely differs from existing methods. The test statistic is the product of the posterior probabilities of the alternative models in the multiple strata. The proposed test is validated in practical examples. Copyright © 2016 John Wiley & Sons, Ltd.

Impact of biomarker changes during neoadjuvant chemotherapy for clinical response in patients with residual breast cancers

BACKGROUND

Residual cancer burden or Ki67 expression levels in residual tumors reportedly provided significant prognostic information for a non-pathological complete response subset after neoadjuvant chemotherapy (NAC). However, the significance of Ki67 reduction for clinical response during chemotherapy in each subtype or menopausal status is yet to be determined.

METHODS

A total of 183 breast cancers surgically removed after chemotherapy were recruited for this study. Expression levels of estrogen receptor (ER), progesterone receptor (PgR), and Ki67 were determined immunohistochemically for semiquantitative measurement and these biomarkers were compared in pre- and post-NAC samples from pathological non-responders (n = 125). Responses to chemotherapy were evaluated both clinically and pathologically.

RESULTS

Ki67 expression levels after NAC (median 5 %, range 0-70 %) were significantly reduced compared with before NAC (25, 1-80 %, P < 0.0001), but only in patients who attained clinical response. This significant suppression of Ki67 in clinical responders was consistently observed in breast cancers from the ER-positive subset, but not the ER-negative subset in the total test set (n = 120). These observations were also made in the validation set (n = 63). Among premenopausal, but not postmenopausal patients, a significant decrease in PgR expression levels was detected in breast cancers of patients who attained clinical response (pre-NAC 50, 0-100 %, post-NAC 5, 0-20 %; P = 0.0003).

CONCLUSION

The impact of Ki67 suppression on clinical response seems to be restricted to ER-positive breast cancers. Since PgR expression levels of premenopausal ER-positive cancers were significantly reduced in clinical responders, inhibition of estrogen signaling due to chemotherapy-induced amenorrhea may be involved in this association.

Standardization of pathologic evaluation and reporting of postneoadjuvant specimens in clinical trials of breast cancer: recommendations from an international working group

Neoadjuvant systemic therapy is being used increasingly in the treatment of early-stage breast cancer. Response, in the form of pathological complete response, is a validated and evaluable surrogate end point of survival after neoadjuvant therapy. Thus, pathological complete response has become a primary end point for clinical trials. However, there is a current lack of uniformity in the definition of pathological complete response. A review of standard operating procedures used by 28 major neoadjuvant breast cancer trials and/or 25 sites involved in such trials identified marked variability in specimen handling and histologic reporting. An international working group was convened to develop practical recommendations for the pathologic assessment of residual disease in neoadjuvant clinical trials of breast cancer and information expected from pathology reports. Systematic sampling of areas identified by informed mapping of the specimen and close correlation with radiological findings is preferable to overly exhaustive sampling, and permits taking tissue samples for translational research. Controversial areas are discussed, including measurement of lesion size, reporting of lymphovascular space invasion and the presence of isolated tumor cells in lymph nodes after neoadjuvant therapy, and retesting of markers after treatment. If there has been a pathological complete response, this must be clearly stated, and the presence/absence of residual ductal carcinoma in situ must be described. When there is residual invasive carcinoma, a comment must be made as to the presence/absence of chemotherapy effect in the breast and lymph nodes. The Residual Cancer Burden is the preferred method for quantifying residual disease in neoadjuvant clinical trials in breast cancer; other methods can be included per trial protocols and regional preference. Posttreatment tumor staging using the Tumor-Node-Metastasis system should be included. These recommendations for standardized pathological evaluation and reporting of neoadjuvant breast cancer specimens should improve prognostication for individual patients and allow comparison of treatment outcomes within and across clinical trials.

Recommendations for standardized pathological characterization of residual disease for neoadjuvant clinical trials of breast cancer by the BIG-NABCG collaboration

Neoadjuvant systemic therapy (NAST) provides the unique opportunity to assess response to treatment after months rather than years of follow-up. However, significant variability exists in methods of pathologic assessment of response to NAST, and thus its interpretation for subsequent clinical decisions. Our international multidisciplinary working group was convened by the Breast International Group-North American Breast Cancer Group (BIG-NABCG) collaboration and tasked to recommend practical methods for standardized evaluation of the post-NAST surgical breast cancer specimen for clinical trials that promote accurate and reliable designation of pathologic complete response (pCR) and meaningful characterization of residual disease. Recommendations include multidisciplinary communication; clinical marking of the tumor site (clips); and radiologic, photographic, or pictorial imaging of the sliced specimen, to map the tissue sections and reconcile macroscopic and microscopic findings. The information required to define pCR (ypT0/is ypN0 or ypT0 yp N0), residual ypT and ypN stage using the current AJCC/UICC system, and the Residual Cancer Burden system were recommended for quantification of residual disease in clinical trials.

Impact of Molecular Subtype Conversion of Breast Cancers after Neoadjuvant Chemotherapy on Clinical Outcome

PURPOSE

The aim of this study was to examine molecular subtype conversions in patients who underwent neoadjuvant chemotherapy (NAC) and analyze their clinical implications.

MATERIALS AND METHODS

We included consecutive breast cancer patients who received NAC at the National Cancer Center, Korea, between August 2002 and June 2011, and had available data on estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor 2 (HER2) receptor status prior to NAC. Molecular subtypes, hormone receptor (HR) status, and ER and PR Allred scores before and after NAC were compared, and the long-term outcomes were analyzed.

RESULTS

Of 322 patients, 32 (9.9%) achieved a pathologic complete response after NAC. HR+/HER2- tumors tended to convert into triple negative (TN) tumors (10.3%), whereas 34.6% of TN tumors gained HR positivity to become HR+/HER2- tumors. Clinical outcomes of molecular subtype conversion groups were compared against patients who remained as HR+/HER2- throughout. The HR+/HER2- to TN group had significantly poorer recurrence-free survival (RFS) (hazard ratio, 3.54; 95% confidence interval [CI], 1.60 to 7.85) and overall survival (OS) (hazard ratio, 3.73; 95% CI, 1.34 to 10.38). Patients who remained TN throughout had the worst outcomes (for RFS: hazard ratio, 3.70; 95% CI, 1.86 to 7.36; for OS: hazard ratio, 5.85; 95% CI, 2.53 to 13.51), while those who converted from TN to HR+/HER2-showed improved comparable survival outcomes.

CONCLUSION

Molecular subtypes of breast cancers changed frequently after NAC, resulting in different tumor prognostication. Tumor subtyping should be repeated after NAC in patients with breast cancer.

Adjuvant endocrine therapy for early breast cancer: a systematic review of the evidence for the 2014 Cancer Care Ontario systemic therapy guideline

BACKGROUND

Cancer Care Ontario's Program in Evidence-Based Care (pebc) recently created an evidence-based consensus guideline on the systemic treatment of early breast cancer. The evidence for the guideline was compiled using a systematic review to answer the question "What is the optimal systemic therapy for patients with early-stage, operable breast cancer, when patient and disease factors are considered?" The question was addressed in three parts: cytotoxic chemotherapy, endocrine treatment, and her2 (human epidermal growth factor receptor 2)-targeted therapy.

METHODS

For the systematic review, the literature in the medline and embase databases was searched for the period January 2008 to May 2014. The Standards and Guidelines Evidence directory of cancer guidelines and the Web sites of major oncology guideline organizations were also searched. The basic search terms were "breast cancer" and "systemic therapy" (chemotherapy, endocrine therapy, targeted agents, ovarian suppression), and results were limited to randomized controlled trials (rcts), guidelines, systematic reviews, and meta-analyses.

RESULTS

Several hundred documents that met the inclusion criteria were retrieved. Meta-analyses from the Early Breast Cancer Trialists' Collaborative Group encompassed many of the rcts found. Several additional studies that met the inclusion criteria were retained, as were other guidelines and systematic reviews.

SUMMARY

The results of the systematic review constitute a comprehensive compilation of high-level evidence, which was the basis for the 2014 pebc guideline on systemic therapy for early breast cancer. The review of the evidence for systemic endocrine therapy (adjuvant tamoxifen, aromatase inhibitors, and ovarian ablation and suppression) is presented here; the evidence for chemotherapy and her2-targeted treatment-and the final clinical practice recommendations-are presented separately in this supplement.

Prognostic factors in operable breast cancer treated with neoadjuvant chemotherapy: towards a quantification of residual disease

OBJECTIVE

Neoadjuvant chemotherapy (NACT) allows for a more frequent use of breast-conservative surgery; it is also an in vivo model of individual tumor sensitivity which permits to determine new prognostic factors to personalize the therapeutic approach.

METHODS

Between 2000 and 2012, 318 patients with primary invasive breast cancer were treated with a median of 6 cycles of NACT; they received either an anthracycline-based FEC 100 protocol (31.1%), or anthracyclines + taxanes (53.5%), with trastuzumab if indicated (15.4%).

RESULTS

After a median follow-up of 44.2 months, the pathological complete response rate according to the classification of Chevallier et al. [Am J Clin Oncol 1993;16:223-228] was 19.3%, and overall (OS) and disease-free survival (DFS) at 10 years were 60.2 and 69.6%, respectively. Univariate analyses demonstrated that the Residual Disease in Breast and Nodes (RDBN) index was the most significant prognostic factor for OS (p = 0.0082) and DFS (p = 0.0022), and multivariate analyses mainly revealed that the residual tumor size, residual involved node number and post-chemotherapy Scarff-Bloom-Richardson (SBR) grading were the most significant prognostic factors.

CONCLUSIONS

In a cohort of patients who were all homogeneously treated with some of the most common drugs for breast cancer, we demonstrate that NACT may provide additional prognostic factors and confirm the RDBN index. As this index allows for the prediction of survival with different breast cancer subtypes, we suggest that it should be calculated routinely to help clinicians to select patients who need adjuvant treatments.

Outcomes of adjuvant endocrine therapy and hormone receptor status change following neoadjuvant chemotherapy in breast cancer patients

BACKGROUND

This retrospective study investigated the therapeutic benefit of adjuvant endocrine therapy (ET) in breast cancer patients with hormone receptor (HR) status change from positive to negative after neoadjuvant chemotherapy (NAC).

METHODS

From December 2000 to November 2010, 97 eligible patients with a positive-to-negative switch of HR status after NAC were identified. All patients were categorized into 2 groups on the basis of the administration of ET: 57 ET-administered patients and 40 ET-naïve patients. Survival analyses were performed to examine the prognostic value of ET administration as well as other clinical and pathologic variables.

RESULTS

The administration of ET was significantly associated with improved disease-free survival (p=0.018) in patients with a positive-to-negative switch of HR status. The 5-year disease-free survival rates were 77.0% and 55.5%, respectively, in ET-administered patients and ET-naïve patients. The 5-year overall survival rate for ET-administered patients was also higher than that of ET-naïve patients (81.3% vs. 72.7%, p=0.053), albeit this was statistically insignificant.

CONCLUSIONS

This study revealed that patients with HR altered from positive to negative after NAC still benefit from ET. The HR status should be evaluated not only in specimens obtained during post-NAC surgery but also in specimens biopsied before NAC.