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Background: Homologous recombination deficiency (HRD)-causing alterations have been reported in triple-negative breast cancer (TNBC). We hypothesized that TNBCs with HRD alterations might be more sensitive to anthracycline plus cyclophosphamide-based chemotherapy and report on HRD status and BRCA1 promoter methylation (PM) as prognostic markers in TNBC patients treated with adjuvant doxorubicin (A) and cyclophosphamide (C) in SWOG9313. Patients and methods: In total, 425 TNBC patients were identified from S9313. HRD score, tumor BRCA1/2 sequencing, and BRCA1 PM were carried out on DNA isolated from formalin-fixed paraffin-embedded tissue. Positive HRD status was defined as either a deleterious tumor BRCA1/2 (tBRCA) mutation or a pre-defined HRD score ≥42. Markers were tested for prognostic value on disease-free survival (DFS) and overall survival (OS) using Cox regression models adjusted for treatment assignment and nodal status. Results: HRD status was determined in 89% (379/425) of cases. Of these, 67% were HRD positive (27% with tBRCA mutation, 40% tBRCA-negative but HRD score≥42). HRD-positive status was associated with a better DFS [hazard ratio (HR) 0.72; 95% confidence interval (CI) 0.51-1.00; P=0.049] and non-significant trend toward better OS (HR=0.71; 95% CI 0.48-1.03; P=0.073). High HRD score (≥42) in tBRCA-negative patients (n=274) was also associated with better DFS (HR=0.64; 95% CI 0.43-0.94; P=0.023) and OS (HR=0.65; 95% CI 0.42-1.00; P=0.049). BRCA1 PM was evaluated successfully in 82% (348/425) and detected in 32% of cases. The DFS HR for BRCA1 PM was similar to that for HRD but did not reach statistical significance (HR=0.79; 95% CI 0.54-1.17; P=0.25). Conclusions: HRD positivity was observed in two-thirds of TNBC patients receiving adjuvant AC and was associated with better DFS. HRD status may identify TNBC patients who receive greater benefit from AC-based chemotherapy and should be evaluated further in prospective studies. [ABSTRACT FROM AUTHOR]

The pivotal phase III ASCENT trial demonstrated improved survival outcomes associated with sacituzumab govitecan (SG), an anti-trophoblast cell-surface antigen 2 (anti-Trop-2) antibody-drug conjugate linked with the topoisomerase-inhibitor SN-38, over single-agent chemotherapy treatment of physician's choice (TPC) in previously treated metastatic triple-negative breast cancer (mTNBC). This prespecified, exploratory biomarker analysis from the ASCENT trial evaluates the association between tumor Trop-2 expression and germline BRCA1/2 mutation status with clinical outcomes. Patients with mTNBC refractory to or progressing after two or more prior chemotherapies, with one or more in the metastatic setting, were randomized to receive SG (10 mg/kg intravenously days 1 and 8, every 21 days) or TPC (capecitabine, eribulin, vinorelbine, or gemcitabine) until disease progression/unacceptable toxicity. Biopsy or surgical specimens were collected at study entry to determine Trop-2 expression level using a validated immunohistochemistry assay and histochemical scoring. Germline BRCA1/2 mutation status was collected at baseline. Of 468 assessable patients, 290 had Trop-2 expression data [64% (n = 151 SG) versus 60% (n = 139 TPC)] and 292 had known BRCA1/2 mutation status [63% (n = 149 SG) versus 61% (n = 143 TPC)]. Median progression-free survival in SG- versus TPC-treated patients was 6.9, 5.6, and 2.7 months versus 2.5, 2.2, and 1.6 months for high, medium, and low Trop-2 expression, respectively. Median overall survival (14.2, 14.9, and 9.3 months versus 6.9, 6.9, and 7.6 months) and objective response rates (44%, 38%, and 22% versus 1%, 11%, and 6%) were numerically higher with SG versus TPC in patients with high, medium, and low Trop-2 expression, respectively. Efficacy outcomes were numerically higher with SG versus TPC in patients with and without germline BRCA1/2 mutations. SG benefits patients with previously treated mTNBC expressing high/medium Trop-2 compared with standard-of-care chemotherapy and regardless of germline BRCA1/2 mutation status. The small number of patients with low Trop-2 expression precludes definitive conclusions on the benefit of SG in this subgroup. • The majority of patients (80%) with mTNBC in the ASCENT study with available data had high/medium tumor Trop-2 expression. • Survival outcomes and ORRs were numerically higher in SG- versus TPC-treated patients with high/medium Trop-2 expression. • Benefit of SG in patients with high/medium Trop-2 expression was similar to that of overall primary efficacy population. • The small number of patients with low Trop-2 expression prevents definitive conclusions on benefit of SG in this subgroup. • Benefit of SG over TPC was also similar regardless of germline BRCA1/2 mutation status. [ABSTRACT FROM AUTHOR]

Dysregulation of various miRNAs has been linked to the initiation and progression of several cancers including acute myeloid leukemia (AML). However, their role in pediatric cytogenetically normal AML (CN-AML) is still unclear. The objective of the present study was to identify deregulated miRNA expression patterns and their correlation with survival outcome in pediatric CN-AML. The study was approved by Institutional Ethical Committee. Informed written consent was taken from all the subjects. Bone marrow (BM) samples from 36 pediatric CN-AML patients and 20 pediatric controls (with solid tumors without BM involvement) were collected and used for isolation of mononuclear cells, genomic DNA and total RNA. Various clinical parameters were accessed and mutation status (NPM1 and FLT3-ITD) determined by PCR. Total RNA from 10 samples (5 CN-AML and 5 controls) was used for global miRNA profiling on Illumina HiSeq2500 platform and data were analysed using bioinformatic pipeline. For all 36 CN-AML patients, cDNA was prepared using TaqMan advanced miRNA cDNA synthesis kit followed by qPCR using TaqMan advanced miRNA assay for selected miRNAs. Global miRNA profiling revealed differential expression of 168 miRNAs of which 66 were upregulated and 102 were downregulated (fold change>1.5, p ≤ 0.05) in pediatric CN-AML patients. Interestingly, 40 miRNAs belonging to human 14q32 miRNA cluster were significantly downregulated in CN-AML patients. The expression of 11 miRNAs selected for qPCR-based validation based on their involvement in signalling pathways in AML (and other cancers), were found to be dysregulated in 36 patients. Most of these miRNAs were found to target genes involved in the initiation and progression of AML. Importantly, there was a significant correlation between expression levels of miR-75, miR-589, miR-4446, miR-889, and miR-654 and survival outcomes like Event-free, Disease-free, and Overall survival. Clinical parameters like TLC, ANC, LDH, Blast percentage were also significantly correlated with survival outcomes. Along with various genetic abnormalities, deregulation in the expression of miRNAs might be an important contributor to the development of pediatric CN-AML. The authors. Department of Biotechnology, Government of India. All authors have declared no conflicts of interest. [ABSTRACT FROM AUTHOR]