Elderly patients with hormone receptor-positive HER2-negative metastatic breast cancer treated with CDK4/6 inhibitors in a multicentre cohort.

INTRODUCTION: Cyclin-dependent kinases 4/6 inhibitors (CDK 4/6i) combined with endocrine therapy have become the gold standard in hormone receptor-positive (HR +) HER2-negative (HER2-) metastatic breast cancer (MBC). However, there is a significant lack of data regarding the efficacy and safety of these treatments in elderly patients. We present the results of a real-world data (RWD) cohort stratified by age at treatment initiation (≥ 70 years compared to patients < 70 years). METHODS: Clinico-pathological data of HR + HER2- MBC patients who were candidates for CDK4/6i therapy between January 2017 and December 2020 at the Institut Català d'Oncologia (Spain) were retrospectively collected. The primary goal was to assess Progression-Free Survival (PFS), Overall Survival (OS), and safety outcomes within this patient population. RESULTS: A total of 274 patients with MBC who received CDK4/6i treatment were included in the study. Among them, 84 patients (30.8%) were aged ≥ 70 years, with a mean age of 75, while 190 patients (69.2%) were under the age of 70, with a mean age of 55.7 years. The most frequently observed grade 3-4 toxicity was neutropenia, with similar rates in both the < 70 group (43.9%) and the ≥ 70 group (47.9%) (p = 0.728). The median Progression-Free Survival (mPFS) for the first-line CDK4/6i treatment was 22 months (95% CI, 15.4-39.8) in the < 70 group and 20.8 months (95% CI 11.2-NR) in the ≥ 70 group (p = 0.67). Similarly, the median PFS for the second-line CDK4/6i treatment was 10.4 months (95% CI, 7.4-15.1) and 7.1 months (95% CI 4.4-21.3) (p = 0.79), respectively. Median overall survival (mOS) was not reached either for the first- and second-line treatment. CONCLUSIONS: Our RWD suggests that elderly patients, when compared to those under 70, experience similar survival outcomes and exhibit comparable tolerance for CDK4/6i therapy.

Genomic characterization and tumor evolution in paired samples of metaplastic breast carcinoma.

Metaplastic breast carcinomas are a rare and heterogeneous group of tumors (0.5-2%). They are mainly triple negative tumors but they present poorer chemotherapy responses and worse prognosis than other triple negative tumors. The aim of our study was to characterize the molecular profile and tumor evolution in matched (primary-relapse) tumor samples from patients with early-stage metaplastic breast carcinomas who had disease recurrence/progression. We performed genomic profiling of tumor biopsies at least from two different time points of their tumor evolution. Tumor samples were analyzed by DNA-Next Generation Sequencing (Illumina 2 x 75bp) using the Action OncoKitDX panel (Imegen-Health in Code group), which includes point mutations in 50 genes, CNVs, and fusion genes. Only pathogenic and likely pathogenic variants were considered for analysis and they were categorized following the ComPerMed criteria. We analyzed 21 matched tumor samples (8 primary and 13 relapse/progression samples). Genomic profiling of matched tumor samples revealed that mutations present in primary tumors are generally maintained in the relapse/disease progression. We did not find a significant increase in point mutations between primary and relapse/progression samples, although gene amplifications were found more frequently in relapse/progression samples. Tumor samples harbored high frequency of TP53 (100%) and TERT promoter (29%) mutations, and of MYC amplifications (80% of which in relapse/progression samples). No PI3KCA mutations were found, but PTEN variations were enriched in 38% of samples (10% mutations and 28% deletions). FGFR1 amplifications were identified in 13% of samples (primary tumor only). Neither ERBB2 nor EGFR gene amplifications were detected. The most frequent pathogenic alterations occurred in cycle regulation's genes, including TP53 and TERT promoter mutations, and MYC amplifications. Relapse/progression samples were highly enriched for MYC amplification. Larger studies are required to better characterize these tumors, and identify new strategies to improve the prognosis of these patients.

Can we avoid axillary lymph node dissection in N2 breast cancer patients with chemo-sensitive tumours such as HER2 and TNBC?

PURPOSE: To find a group of cN2 patients or patients with high axillary burden who become ypN0 after neoadjuvant chemotherapy (NACT) and who may benefit from avoiding a lymphadenectomy. METHODS: A retrospective observational cohort study was conducted with 221 clinically staged N2 patients or patients with at least 3 suspicious lymph nodes found by ultrasound at diagnosis. The predictive factors for ypN0 analysed were age, MRI-determined tumour size, histological subtype, the Nottingham histologic grade, surrogate molecular subtype, ki-67 and vascular invasion when present. Clinical and radiological responses after NACT were also evaluated. Univariate and multivariate analyses by logistic regression were performed. Distant disease-free survival (DDFS) was calculated in relation to the status of the axillary lymph nodes after NACT. RESULTS: After NACT, 89 patients (40.3%) had axillary pathologic complete response (pCR) (ypN0) and 132 (59.7%) had residual axillary disease (ypN+). Molecular surrogate subtype, Ki-67 expression, and the clinical and radiological responses to NACT were the only independent factors associated with ypN0. Axillary pCR was observed more often in HER2-positive and triple-negative tumours than in luminal ones (OR 7.5 and 3.6, respectively). DDFS was 88.7% (95% CI 80.7-96.7%) for ypN0 and 56.2% (95% CI 32.1-80.3%) for ypN+ (p = 0.09). CONCLUSIONS: In HER2-positive and triple-negative breast cancer patients staged as cN2 or with high axillary burden before NACT, a sentinel lymph node biopsy after NACT could be recommended if there is a clinical and radiological response.

Real-world efficacy and safety of eribulin in advanced and pretreated HER2-negative breast cancer in a Spanish comprehensive cancer center.

BACKGROUND: Eribulin improves survival in pre-treated HER2-negative advanced breast cancer (ABC). However, limited data exist on co-morbidities and central nervous system (CNS) efficacy. The purpose of this study was to review eribulin's efficacy and safety in everyday clinical practice with special focus on age, body mass index (BMI) and central nervous system (CNS) activity. METHODS: An observational study was conducted in a series of HER2-negative ABC patients treated from January'14-December'17 outside a clinical trial. Objective Response Rate (ORR), Progression Free Survival (PFS), Overall Survival (OS), and association of clinical and pathological variables with outcome were evaluated. RESULTS: Ninety-five women were treated with at least one cycle of eribulin. Median age was 57 (33-83), and 18% were obese. Median number of prior chemotherapies for ABC was 3 (2-5) and 76% of patients had visceral metastases, including 21% with CNS involvement. Most tumors were estrogen receptor-positive (79%). ORR and stable disease (SD) at 6 months were 26.2 and 37.5%, respectively. Remarkably, relevant CNS efficacy was observed with eribulin: 20% of patients obtained partial response and 25% SD. Treatment was generally well tolerated and manageable, with 29% grade 3 and 10.9% grade 4 toxicities. Median PFS and OS were 4.1 months (CI95% 3.2-4.9) and 11.1 months (CI95% 9.5-14.7), respectively. Triple-negative disease, > 2organs involved and being younger than 70 years old were independent prognosis factors for worse OS in multivariate analysis. Most patients (75%) progressed in pre-existing metastases sites. CONCLUSION: In everyday clinical practice, eribulin's efficacy seems similar to pivotal trials. CNS-efficacy was observed. TNBC, > 2 organs involved and being younger than 70 years old were independent prognosis factors for worse OS. Remarkably, less incidence of grade 4-toxicity compared to previous studies was found.