Clinical correlates of 'BRCAness' in triple-negative breast cancer of patients receiving adjuvant chemotherapy.

BACKGROUND

We have previously reported an array comparative genomic hybridization profile that identifies triple-negative breast cancers (TNBC), with BRCA1 dysfunction and a high sensitivity to intensified dose bifunctional alkylating agents. To determine the effect of conventional-dose chemotherapy in patients with this so-called BRCA1-like profile, clinical characteristics and survival were studied in a large group of TNBC patients.

METHODS

DNA was isolated and BRCA1-like status was assessed in 101 patients with early-stage TNBC receiving adjuvant cyclophosphamide-based chemotherapy. Clinical characteristics and survival were compared between BRCA1-like and non-BRCA1-like groups. Results Sixty-six tumors (65%) had a BRCA1-like profile. Patients with BRCA1-like tumors tended to be younger and had more often node-negative disease (P = 0.06 and P = 0.03, respectively). Five-year recurrence-free survival was 80% for the BRCA1-like group and 75% for the non-BRCA1-like group (P = 0.35). T stage was the only variable significantly associated with survival.

CONCLUSIONS

BRCA1-like tumors share clinical features, like young age at diagnosis and similar nodal status, with breast cancers in BRCA1 mutation carriers. Their prognosis is similar to that of non-BRCA1-like tumors when conventional-dose chemotherapy is administered. TNBCs that are classified as BRCA1-like may contain a defect in homologous recombination and could, in theory, benefit from the addition of poly ADP ribose polymerase inhibitors.