O2-2-3 [Encore] Phase II trial of GEMOX for the advanced pancreatic cancer with family/personal history of HBOC related cancer.

Background A family and personal history of breast (B), ovarian(O), and pancreatic(P) cancer was reported to be a predictive marker in patients with pancreatic adenocarcinoma (PA) treated with platinum-based chemotherapy. We planned a prospective phase II trial to evaluate the efficacy and safety of platinum-based chemotherapy in this population. Method Eligible patients had chemotherapy-naïve metastatic PA, had one or more of the followings: 1) at least one family history of P/B/O/prostate (PR) cancer in a first-degree relative, 2) at least two family members with history of P/B/O/PR cancer within third-degree relatives, and 3) at least one personal history of B/O/PR cancer.Patient suitable for FOLFIRINOX or gemcitabine plus nab-paclitaxel were ineligible unless patient refuse those regimens. Patients received gemcitabine 1000mg/m2and oxaliplatin 100 mg/m2 every two weeks (GEMOX). The primary endpoint was the one-year survival rate and 44% were desired. The sample size was calculated to be 43 pts, with a one-sided alpha of 5% and a power of 80%. Results A total of 45 pts were enrolled. First 43 pts were included in primary analysis. One-year survival rate was 27.9 [90%CI;17.0-41.3]% and didn't met pre-planned boundary. Response rate was 27.9%. Tendency of prolonged survival was observed in patients with two or more family histories of P/B/O/PR cancer (HR 0.65, 95%CI [0.34-1.23]). Family history or personal history with B/O/PR cancer tended to be associate with better response and prolonged survival. In this study, patient with family history of pancreatic cancer seemed to be associate with poor response. The most common adverse events of grade 3 or higher were neutropenia (36%), leukopenia (27%), thrombocytopenia (23%) and elevated level of ALT (20%). Treatment related death was not observed. Conclusion GEMOX did not show expected efficacy in patients with metastatic PA with family history or personal history of P/B/O/PR cancer. [ABSTRACT FROM AUTHOR]