Mitomycin C plus cisplatin for systemic treatment of recurrent BRCA1-associated ovarian cancer

Background Previous studies on neoadjuvant therapy for BRCA1-driven ovarian cancer (OC) demonstrated higher efficacy of mitomycin C plus cisplatin combination as compared to standard drug schemes. These data call for evaluation of the utility of this regimen for the treatment of recurrent BRCA1-associated OC. Methods The study included 12 BRCA1 germ-line mutation carriers, whose disease relapsed after one (n = 4) or two (n = 8) lines of chemotherapy. The patients received cisplatin 100 mg/m² and mitomycin C 10 mg/m², given every four weeks, for 6 (n = 10), 8 (n = 1) or 5 (n = 1) cycles. Retrospective data on conventional treatment of OC relapses in BRCA1 heterozygotes (n = 47) served as a control. Results Grade 3-4 toxicities were observed in 4/12 (33%) cases. There were 6 complete responses (CR), 4 partial responses (PR) and 2 instances of stable disease (SD). Comparison of patients receiving mitomycin C plus cisplatin (n = 4) or conventional therapy (n = 44) at first relapse demonstrated marginal improvement of the progression-free survival (PFS) (16.6 months vs. 10.2 months, P = .067). Use of mitomycin C plus cisplatin (n = 8) for the treatment of second relapse resulted in significant prolongation of PFS as compared to standard regimens (n = 31) (14.8 months vs. 4.8 months, P = .002). Conclusions Mitomycin C plus cisplatin shows promising activity in recurrent BRCA1-driven ovarian cancer.