Comparative analysis of telomere length in peripheral blood of breast cancer BRCA1 mutation carriers and non-carriers

INTRODUCTION: Breast cancer is the most prevalent malignancy among women worldwide. A significant portion of patients possess homologous recombination deficiency (HRD), often caused by BRCA1/2 mutations, which may sensitize tumors to PARP inhibitors and platinum-based chemotherapy through synthetic lethality. Since mutations in BRCA genes have been previously suggested in association with impaired biology of telomeres, in the present study we investigated leukocyte telomere length (LTL) to evaluate its potential utility as a biomarker for BRCA1 mutations and HRD. METHODOLOGY: LTL was measured using multiplex monochrome real-time qPCR in four groups: breast cancer patients with pathogenic hereditary BRCA1 mutations (n = 99), age-matched non-cancerous controls carrying the same BRCA1 mutations (n = 99), breast cancer patients with wild-type BRCA1 (n = 105), and age-matched non-cancerous controls with wild-type BRCA1 (n = 107). BRCA1 mutations were tested by the DNA sequencing approach. RESULTS: A significant negative correlation between age and LTL was observed across all studied groups, except in breast cancer patients carrying pathogenic hereditary BRCA1 mutations. Interestingly, after adjusting for age, BRCA1 mutation carriers had shorter LTL compared to non-carriers, regardless of the presence of cancer (P = 0.024). CONCLUSION: LTL shortening is associated with BRCA1 mutations, regardless of cancer status. Further validation studies are needed.