Search

Only a handful of somatic alterations have been linked to endocrine therapy resistance in hormone-dependent breast cancer, potentially explaining ∼40% of relapses. If other mechanisms underlie the evolution of hormone-dependent breast cancer under adjuvant therapy is currently unknown. In this work, we employ functional genomics to dissect the contribution of cis-regulatory elements (CRE) to cancer evolution by focusing on 12 megabases of noncoding DNA, including clonal enhancers, gene promoters, and boundaries of topologically associating domains. Parallel epigenetic perturbation (CRISPRi) in vitro reveals context-dependent roles for many of these CREs, with a specific impact on dormancy entrance and endocrine therapy resistance. Profiling of CRE somatic alterations in a unique, longitudinal cohort of patients treated with endocrine therapies identifies a limited set of noncoding changes potentially involved in therapy resistance. Overall, our data uncover how endocrine therapies trigger the emergence of transient features which could ultimately be exploited to hinder the adaptive process. Significance: This study shows that cells adapting to endocrine therapies undergo changes in the usage or regulatory regions. Dormant cells are less vulnerable to regulatory perturbation but gain transient dependencies which can be exploited to decrease the formation of dormant persisters., (©2024 The Authors; Published by the American Association for Cancer Research.)

Background: Hormone receptor expression is a known positive prognostic and predictive factor in breast cancer; however, limited evidence exists on its prognostic impact on prognosis of young patients harboring a pathogenic variant (PV) in the BRCA1 and/or BRCA2 genes., Patients and Methods: This international, multicenter, retrospective cohort study included young patients (aged ≤40 years) diagnosed with invasive breast cancer and harboring germline PVs in BRCA genes. We investigated the impact of hormone receptor status on clinical behavior and outcomes of breast cancer. Outcomes of interest [disease-free survival (DFS), breast cancer-specific survival (BCSS), and overall survival (OS)] were first investigated according to hormone receptor expression (positive versus negative), and then according to breast cancer subtype [luminal A-like versus luminal B-like versus triple-negative versus human epidermal growth factor receptor 2 (HER2)-positive breast cancer]., Results: From 78 centers worldwide, 4709 BRCA carriers were included, of whom 2143 (45.5%) had hormone receptor-positive and 2566 (54.5%) hormone receptor-negative breast cancer. Median follow-up was 7.9 years. The rate of distant recurrences was higher in patients with hormone receptor-positive disease (13.1% versus 9.6%, P < 0.001), while the rate of second primary breast cancer was lower (9.1% versus 14.7%, P < 0.001) compared to patients with hormone receptor-negative disease. The 8-year DFS was 65.8% and 63.4% in patients with hormone receptor-positive and negative disease, respectively. The hazard ratio of hormone receptor-positive versus negative disease changed over time for DFS, BCSS, and OS (P < 0.05 for interaction of hormone receptor status and survival time). Patients with luminal A-like breast cancer had the worst long-term prognosis in terms of DFS compared to all the other subgroups (8-year DFS: 60.8% in luminal A-like versus 63.5% in triple-negative versus 65.5% in HER2-positive and 69.7% in luminal B-like subtype)., Conclusions: In young BRCA carriers, differences in recurrence pattern and second primary breast cancer among hormone receptor-positive versus negative disease warrant consideration in counseling patients on treatment, follow-up, and risk-reducing surgery., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: The ROXANE Italian prospective study evaluated the impact of the 21-gene Recurrence Score (RS) results on adjuvant treatment decision for patients with early breast cancer., Materials and Methods: Nine centers participated. Physicians used the RS test whenever unsure about adjuvant treatment recommendation for patients with estrogen receptor-positive/human epidermal growth receptor 2-negative, T1-T3, N0-N1 early breast cancer. Pre-RS and post-RS treatment recommendations were collected., Results: A total of 251 patients were included. N0 patients (61%) showed higher grade ( p < .001) and higher Ki67 ( p = .001) and were more frequently progesterone receptor negative ( p = .012) as compared with N1 patients. RS results were as follows: <11, n = 63 (25.1%); 11-25, n = 143 (57%); and ≥26, n = 45 (17.9%). Higher RS was found in N0 vs. N1 patients ( p = .001) and in cases of G3 ( p < .001) and higher Ki67 ( p < .001). The rate of change in treatment decision was 30% ( n = 75), mostly from chemotherapy (CT) plus hormone therapy (CT + HT) to hormone therapy (HT; 76%, n = 57/75). The proportion of patients recommended to CT + HT was significantly reduced from pre-RS to post-RS (52% to 36%, p < .0001). CT use reduction was more evident for N1 patients (55% to 27%) than for N0 patients (50% to 42%) and was observed only in cases of RS ≤17., Conclusion: Physicians predominantly used the 21-gene assay in N0 patients with a more aggressive biology or in N1 patients showing more indolent biology. In this selected patient population, the use of RS testing led to a 30% rate of change in treatment decision. In the N1 patient subgroup, the use of RS testing contributed to reduce CT use by more than half., Implications for Practice: This study shows that, even in a context in which physicians recommend a high proportion of patients to endocrine treatment alone before knowing the results of the Recurrence Score (RS) assay, the use of the RS test, whenever uncertainty regarding adjuvant treatment recommendation is present, significantly contributes in further reducing the use of chemotherapy, especially for N1 patients., Competing Interests: Disclosures of potential conflicts of interest may be found at the end of this article., (© AlphaMed Press 2019.)

Background: In human epidermal growth factor receptor 2 (HER2+) breast cancers, neoadjuvant trials of chemotherapy plus anti-HER2 treatment consistently showed lower pathologic complete response (pCR) rates in hormone receptor (HR) positive versus negative tumors. The PerELISA study was aimed to evaluate the efficacy of a de-escalated, chemotherapy-free neoadjuvant regimen in HR+/HER2+ breast cancer patients selected on the basis of Ki67 inhibition after 2-week letrozole., Patients and Methods: PerELISA is a phase II, multicentric study for postmenopausal patients with HR+/HER2+ operable breast cancer. Patients received 2-week letrozole, and then underwent re-biopsy for Ki67 evaluation. Patients classified as molecular responders (Ki67 relative reduction >20% from baseline) continued letrozole and started trastuzumab-pertuzumab for five cycles. Patients classified as molecular non-responders started weekly paclitaxel for 13 weeks combined with trastuzumab-pertuzumab. Primary aim was breast and axillary pCR. According to a two-stage Simon's design, to reject the null hypothesis, at least 8/43 pCR had to be documented., Results: Sixty-four patients were enrolled, 44 were classified as molecular responders. All these patients completed the assigned treatment with letrozole-trastuzumab-pertuzumab and underwent surgery. A pCR was observed in 9/44 cases (20.5%, 95% confidence interval 11.1% to 34.5%). Among molecular non-responders, 16/17 completed treatment and underwent surgery, with pCR observed in 81.3% of the cases. PAM50 intrinsic subtype was significantly associated with Ki67 response and pCR. Among molecular responders, the pCR rate was significantly higher in HER2-enriched than in other subtypes (45.5% versus 13.8%, P = 0.042)., Conclusions: The primary end point of the study was met, by reaching the pre-specified pCRs. In patients selected using Ki67 reduction after short-term letrozole exposure, a meaningful pCR rate can be achieved without chemotherapy. PAM50 intrinsic subtyping further refines our ability to identify a subset of patients for whom chemotherapy might be spared., Eudract Number: 2013-002662-40., Clinicaltrials.gov Identifier: NCT02411344., (© The Author(s) 2019. Published by Oxford University Press on behalf of the European Society for Medical Oncology.)

Even if breast cancer has not been traditionally considered an immunogenic tumor, recent data suggest that immunity, and its interaction with tumor cells and tumor microenvironment, might play an important role in this malignancy, in particular in triple negative and HER2+ subtypes. As no consistent data on the potential clinical relevance of tumor infiltrating lymphocytes have been produced in hormone receptor positive (HR+) HER2- breast cancer, the interest in studying immune aspects in this subtype has become less appealing. Nevertheless, some scattered evidence indicates that immunity and inflammation may be implicated in the biology of this subtype as well. In HR+ breast cancer, the interaction between tumor cells and the immune milieu might rely on different mechanisms than in other BC subtypes, involving the modulation of the tumor microenvironment by mutual interplays of endocrine factors, pro-inflammatory status and immune cells. These subtle mechanisms may require more refined methods of evaluation, such as the assessment of tumor infiltrating lymphocytes subpopulations or gene signatures. In this paper we aim to perform a comprehensive review of pre-clinical and clinical data on the interplay between the immune system and breast cancer in the HR+ subtype, to guide further research in the field., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Background: The aim of this study was to evaluate the prognostic impact of quantitative estrogen receptor (ER) expression at relapse for ER-positive breast cancer with ER-positive recurrence., Patients and Methods: A total of 81 patients with ER-positive primary breast cancer and ER-positive paired recurrence were included. ER expression was evaluated as the percentage of tumor cells staining for ER under immunohistochemistry. Samples were defined as ER-high (ER>50%) or ER-low (ER≥10% and ≤50%)., Results: Quantitative ER expression on relapse biopsy was an independent prognostic factor for overall survival in multivariate analysis, both as a continuous (hazard ratio=0.8; 95% confidence interval=0.7-0.92, p=0.001) and as a categorical (ER-high vs. ER-low; hazard ratio=0.26; 95% confidence interval=0.11-0.59, p=0.001) variable. Patients whose status changed from ER-high (primary BC) to ER-low (relapse) had the poorest outcome, with a 10-year overall survival rate of 14%., Conclusion: Even in the case of maintenance of ER-positivity on primary and relapse of breast cancer, recurrence biopsy provides prognostic information., (Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.)

Background: Tumor phenotype may change during breast cancer progression. This study evaluates the prognostic impact of receptor discordance between paired primaries and recurrences., Patients and Methods: One hundred and thirty-nine patients underwent histological sampling of suspected breast cancer recurrence. All the pathology assessments [ER, PgR and human epidermal growth factor receptor 2 (HER2)] on both primaries and confirmed recurrences were performed at the same laboratory., Results: A breast cancer recurrence was confirmed in 119 cases. Rates of discordance were 13.4%, 39% and 11.8% for ER, PgR and HER2, respectively. Ninety-two patients maintained the same tumor phenotype [i.e. the same hormone receptors (HR) and HER2 status], whereas 27 (22.7%) changed during progression. The loss of HR positivity and the loss of HER2 positivity resulted in a worse post-recurrence survival (P=0.01 and P=0.008, respectively) and overall survival (OS; P=0.06 and P=0.0002, respectively), compared with the corresponding concordant-positive cases. Tumor phenotype discordance was associated with worse post-recurrence and OS (P=0.006 and P=0.002, respectively); those cases who turned into triple-negative experienced the poorest outcome, respect to the concordant group (P=0.001, OS)., Conclusions: We demonstrated for the first time an impact on OS of phenotype discordance between primary breast cancer and relapse. Among discordant cases, receptor loss resulted in the main determinant of poorer outcome.

Introduction: The assessment of hormone receptors (HRs) and human epidermal growth factor receptor (HER)-2 is necessary to select patients who are candidates for hormonal and anti-HER-2 therapy. The evaluation of these parameters is generally carried out in primary tumors and it is not clear if reassessment in metastatic lesions might have an impact on patient management. The primary aim of this analysis was to compare HER-2 and HR status in primary tumors versus metastatic sites in breast cancer patients., Patients and Methods: Seventy-five patients with available samples from primary tumors and paired metastases were included. HER-2 status was evaluated by immunohistochemistry (IHC) and/or fluorescence in situ hybridization (FISH); HR status was assessed by IHC., Results: Nineteen percent of primary tumors were HER-2 positive; 77% were HR positive. Sites of biopsied or resected metastases were: locoregional soft tissues (n = 30), liver (n = 20), central nervous system (n = 5), bone (n = 5), pleura (n = 4), distant soft tissues (n = 3), abdomen (stomach, colon, peritoneum) (n = 3), bronchus (n = 3), and bone marrow (n = 2). For paired metastases, the HER-2 status was unchanged in 84% of cases; two patients changed from positive to negative, while 10 patients converted from negative to positive (agreement, 84%; kappa = 0.5681). A change in HR status was observed in 16 cases (21%): nine cases from positive to negative and seven cases from negative to positive (agreement, 78.7%; kappa = 0.4158)., Conclusions: Further studies are necessary to better define the level of discordance in HER-2 or HR status between primary tumors and paired metastases. However, a biopsy of metastatic disease can be recommended, if feasible with minimal invasiveness, because treatment options might change for a significant proportion of patients.