ObjectiveTo retrospectively compare primary treatment with weekly carboplatin/paclitaxel (PC-W) to the standard 3-weekly carboplatin/paclitaxel (PC-3W) in women with advanced epithelial ovarian cancer, tubal carcinoma and primary peritoneal carcinoma. MethodsMedical records were assessed for age, stage of disease, tumor histology and grade, BRCA mutation status, and platinum sensitivity. Patients were treated with either paclitaxel (175mg/m2) and carboplatin (AUC 6) every three weeks (PC-3W; 133 patients), or with weekly paclitaxel (80mg/m2) and weekly carboplatin (AUC 2) on days 1, 8, and 15 every 28days (PC-W; 267 patients). ResultsPatient baseline characteristics were similar in both groups. Median overall survival (OS) was similar for PC-W and PC-3W (64.5months vs. 61.5months), but PC-W had longer median progression-free survival [PFS: 27.4months (95% CI, 22.7–31.4) vs. 19.5months (95% CI, 15.6–22.2) for PC-3W, p=0.0024] and a longer median platinum-free interval [PFI: 22.1months (95% CI, 16.0–24.5) vs. 14.2months (95% CI, 10.7–17.2) for PC-3W, p=0.0075]. PC-W showed a significantly higher response rate (86.4% vs. 77.9% for PC-3W, p=0.0435). Multivariate analysis including for age at diagnosis, stage of disease, optimal debulking, histology, BRCA status, pretreatment CA-125 and PFI revealed that the PC-W women had lower risk of death (HR=0.587, 95% CI, 0.402–0.857, p=0.0058), lower risk of disease progression (HR=0.494, 95% CI, 0.359–0.680, p<0.0001), higher 2- and 3-year survival rates, and decreased grade II hair loss, neuropathy and thrombocytopenia compared with the PC-3W women. ConclusionThe PC-W protocol improved PFS and had a similar OS as PC-3W.