The prognostic relevance of FOXA1 and Nestin expression in breast cancer metastases: a retrospective study of 164 cases during a 10-year period (2004–2014)

Abstract Background Current prognostic markers cannot adequately predict the clinical outcome of breast cancer patients. Therefore, additional biomarkers need to be included in routine immune panels. FOXA1 was a significant predictor of favorable outcome in primary breast cancer, while Nestin expression is preferentially found in triple-negative tumors with increased rate of nodal metastases, and reduced survival. No studies have investigated the prognostic value of FOXA1 and Nestin expression in breast cancer metastases. Methods Breast cancer metastases (n = 164) from various anatomical sites were retrospectively analyzed by immunohistochemistry for FOXA1, Nestin and GATA3 expression. Cox regression analysis assessed the prognostic value of FOXA1 and Nestin expression. Results In breast cancer metastases, FOXA1 expression was associated with Nestin-negativity, GATA3-positivity, ER-positivity, HER2-positivity and non-triple-negative status (P < 0.05). In contrast, Nestin expression was associated with FOXA1-negative, GATA3-negative, ER-negative, and triple-negative metastases (P < 0.05). Univariate Cox regression analysis showed FOXA1 expression was predictive of overall survival (OS, P = 0.00048) and metastasis-free survival (DMFS, P = 0.0011), as well as, distant metastasis-free survival in ER-positive patients (P = 0.036) and overall survival in ER-negative patients (P = 0.024). Multivariate analysis confirmed the significance of FOXA1 for both survival endpoints in metastatic breast cancer patients (OS, P = 0.0033; DMFS, P = 0.015). Conclusions In our study, FOXA1 was expressed mostly in ER-positive breast cancer metastases. Expression of Nestin was related to triple-negative metastases, where brain was the most frequent metastatic site. These findings highlight the clinical utility of FOXA1 and Nestin expression and warrant their inclusion in routine immunohistochemical panels for breast carcinoma

Effect of Radiotherapy After Breast-Conserving Surgery Depending on the Presence of Tumor-Infiltrating Lymphocytes : A Long-Term Follow-Up of the SweBCG91RT Randomized Trial

PURPOSE: The effects of radiotherapy (RT) on the basis of the presence of stromal tumor infiltrating lymphocytes (TILs) have not been studied. The purpose of this study was to analyze the association of TILs with the effect of postoperative RT on ipsilateral breast tumor recurrence (IBTR) in a large randomized trial. METHODS: In the SweBCT91RT (Swedish Breast Cancer Group 91 Radiotherapy) trial, 1,178 patients with breast cancer stage I and II were randomly assigned to breast-conserving surgery plus postoperative RT or breast-conserving surgery only and followed for a median of 15.2 years. Tumor blocks were retrieved from 1,003 patients. Stromal TILs were assessed on whole-section hematoxylin-eosin-stained slides using a dichotomized cutoff of 10%. Subtypes were scored using immunohistochemistry on tissue microarray. In total, 936 patients were evaluated. RESULTS: Altogether, 670 (71%) of patients had TILs less than 10%. In a multivariable regression analysis with IBTR as dependent variable and RT, TILs, subtype, age, and grade as independent variables, RT (hazard ratio [HR], 0.42; 95% CI, 0.29 to 0.61; P < .001), high TILs (HR, 0.61; 95% CI, 0.39 to 0.96, P = .033) grade (3 v 1; HR, 2.17; 95% CI, 1.08 to 4.34; P = .029), and age (≥ 50 v < 50 years; HR, 0.55; 95% CI, 0.38 to 0.80; P = .002) were predictive of IBTR. RT was significantly beneficial in the low TILs group (HR, 0.37; 95% CI, 0.24 to 0.58; P < .001) but not in the high TILs group (HR, 0.58; 95% CI, 0.28 to 1.19; P = .138). The test for interaction between RT and TILs was not statistically significant (P = .317). CONCLUSION: This study shows that high values of TILs in the primary tumor independently seem to reduce the risk for an IBTR. Our findings further suggest that patients with breast cancer with low TILs may derive a larger benefit from RT regarding the risk of IBTR

Clonal relatedness in tumour pairs of breast cancer patients

Abstract Background Molecular classification of tumour clonality is currently not evaluated in multiple invasive breast carcinomas, despite evidence suggesting common clonal origins. There is no consensus about which type of data (e.g. copy number, mutation, histology) and especially which statistical method is most suitable to distinguish clonal recurrences from independent primary tumours. Methods Thirty-seven invasive breast tumour pairs were stratified according to laterality and time interval between the diagnoses of the two tumours. In a multi-omics approach, tumour clonality was analysed by integrating clinical characteristics (n = 37), DNA copy number (n = 37), DNA methylation (n = 8), gene expression microarray (n = 7), RNA sequencing (n = 3), and SNP genotyping data (n = 3). Different statistical methods, e.g. the diagnostic similarity index (SI), were used to classify the tumours as clonally related recurrences or independent primary tumours. Results The SI and hierarchical clustering showed similar tendencies and the highest concordance with the other methods. Concordant evidence for tumour clonality was found in 46% (17/37) of patients. Notably, no association was found between the current clinical guidelines and molecular tumour features. Conclusions A more accurate classification of clonal relatedness between multiple breast tumours may help to mitigate treatment failure and relapse by integrating tumour-associated molecular features, clinical parameters, and statistical methods. Guidelines need to be defined with exact thresholds to standardise clonality testing in a routine diagnostic setting

Response to radiotherapy after breast-conserving surgery in different breast cancer subtypes in the Swedish Breast Cancer Group 91 radiotherapy randomized clinical trial

Purpose: To evaluate the effect of adjuvant radiotherapy (RT) after breast conservation surgery in different breast cancer subtypes in a large, randomized clinical trial with long-term follow-up. Patients and Methods: Tumor tissue was collected from 1,003 patients with node-negative, stage I and II breast cancer who were randomly assigned in the Swedish Breast Cancer Group 91 Radiotherapy trial between 1991 and 1997 to breast conservation surgery with or without RT. Systemic adjuvant treatment was sparsely used (8%). Subtyping was performed with immunohistochemistry and in situ hybridization on tissue microarrays for 958 tumors. Results: RT reduced the cumulative incidence of ipsilateral breast tumor recurrence (IBTR) as a first event within 10 years for luminal A–like tumors (19% v 9%; P = .001), luminal B–like tumors (24% v 8%; P, .001), and triple-negative tumors (21% v 6%; P = .08), but not for human epidermal growth factor receptor 2–positive (luminal and nonluminal) tumors (15% v 19%; P = .6); however, evidence of an overall difference in RT effect between subtypes was weak (P = .21). RT reduced the rate of death from breast cancer (BCD) for triple-negative tumors (hazard ratio, 0.35; P = .06), but not for other subtypes. Death from any cause was not improved by RT in any subtype. A hypothesized clinical low-risk group did not have a low risk of IBTR without RT, and RT reduced the rate of IBTR as a first event after 10 years (20% v 6%; P = .008), but had no effect on BCD or death from any cause. Conclusion: Subtype was not predictive of response to RT, although, in our study, human epidermal growth factor receptor 2–positive tumors seemed to be most radioresistant, whereas triple-negative tumors had the largest effect on BCD. The effect of RT in the presumed low-risk luminal A–like tumors was excellent