Advances in Early Breast Cancer Risk Profiling: From Histopathology to Molecular Technologies

Early breast cancer (BC) is the definition applied to breast-confined tumors with or without limited involvement of locoregional lymph nodes. While risk stratification is essential for guiding clinical decisions, it can be a complex endeavor in these patients due to the absence of comprehensive guidelines. Histopathological analysis and biomarker assessment play a pivotal role in defining patient outcomes. Traditional histological criteria such as tumor size, lymph node involvement, histological type and grade, lymphovascular invasion, and immune cell infiltration are significant prognostic indicators. In addition to the hormone receptor, HER2, and-in specific scenarios-BRCA1/2 testing, molecular subtyping through gene expression profiling provides valuable insights to tailor clinical decision-making. The emergence of "omics" technologies, applicable to both tissue and liquid biopsy samples, has broadened our arsenal for evaluating the risk of early BC. However, a pressing need remains for standardized methodologies and integrated pathological models that encompass multiple analytical dimensions. In this study, we provide a detailed examination of the existing strategies for early BC risk stratification, intending to serve as a practical guide for histopathologists and molecular pathologists.

PARP-inhibition reprograms macrophages toward an anti-tumor phenotype

Poly(ADP)ribosylation inhibitors (PARPis) are toxic to cancer cells with homologous recombination (HR) deficiency but not to HR-proficient cells in the tumor microenvironment (TME), including tumor-associated macrophages (TAMs). As TAMs can promote or inhibit tumor growth, we set out to examine the effects of PARP inhibition on TAMs in BRCA1-related breast cancer (BC). The PARPi olaparib causes reprogramming of TAMs toward higher cytotoxicity and phagocytosis. A PARPi-related surge in NAD+ increases glycolysis, blunts oxidative phosphorylation, and induces reverse mitochondrial electron transport (RET) with an increase in reactive oxygen species (ROS) and transcriptional reprogramming. This reprogramming occurs in the absence or presence of PARP1 or PARP2 and is partially recapitulated by addition of NAD derivative methyl-nicotinamide (MNA). In vivo and ex vivo, the effect of olaparib on TAMs contributes to the anti-tumor efficacy of the PARPi. In vivo blockade of the "don't-eat-me signal" with CD47 antibodies in combination with olaparib improves outcomes in a BRCA1-related BC model.

Efficacy of different neoadjuvant treatment regimens in BRCA-mutated triple negative breast cancer: a systematic review and meta-analysis

Purpose

Triple negative breast cancer (TNBC) is an aggressive breast cancer strongly associated with BRCA mutation. Standard neoadjuvant chemotherapy remains the standard of care for early stage TNBC, the optimal chemotherapy regimen is still a matter of discussion. Other agents, such as poly-ADP-ribosyl polymerase inhibitors (PARPi) and anti-vascular endothelial growth factor (VEGF) antibodies were evaluated in the neoadjuvant setting. This systematic review and meta-analysis intend to evaluate the impact of neoadjuvant treatments in pCR rates in TNBC gBRCA mutation, beyond traditional standard chemotherapy.

Methods

PubMed, Clinicaltrials.gov, Cochrane CENTRAL, Embase and key oncological meetings for trials were searched for studies reporting neoadjuvant chemo-immunotherapy in BRCA positive TNBC.

Results

Out of 1238 records reviewed, thirty-one trials were included, resulting in a total 619 BRCA-mutated TNBC patients. In BRCA mutated TNBC patients who received cisplatin in monotherapy the proportion of patients who achieved pCR was 0.53 (95%CI [0.30, 0.76]), and when treatment combined standard chemotherapy and platin derivatives the proportion of pCR increased to 0.62 (95% CI [0.48, 0.76]). The group of patients treated with platin derivatives, anthracyclines ± taxanes achieved the highest proportion of pCR, 0.66. Patients treated with PARPi alone show a pCR proportion of 0.55 (95% CI [0.30, 0.81]); and when standard chemotherapy and platin derivatives were combined with PARPi the proportion of pCR did not vary.

Conclusions

Patients with BRCA mutated TNBC treated with cisplatin in monotherapy demonstrate inferior proportion in the pCR achievement when compared with standard chemotherapy plus platin derivates. The best pCR was achieved with platin derivates in association with anthracyclines ± taxanes. No difference in pCR was found between PARPi alone vs PARPi with standard chemotherapy.