The aim was to compare the two most commonly recommended chemotherapy regimens (platinum-based chemotherapy and platinum–taxane combination) with non-platinum-based chemotherapy and those with no chemotherapy in a large nationwide and population-based cohort of patients with ovarian cancer with up to 17 years of follow-up. We studied 12,181 patients diagnosed with stages I–IV ovarian cancer at age ≥65 in 1991–2005 from the 16 areas of the United States. We also performed matched cohort analyses based on conditional probability of receiving platinum chemotherapy in 3,428 patients. In patients with early stage ovarian cancer, those who received platinum–taxane combination had the highest 5-year all-cause (62.5 %) and cancer-specific (65.1 %) survival rates, as compared to 51.5 and 63.7 % in those without chemotherapy. After adjusting for potential confounders, hazard ratios of all-cause mortality (0.66, 95 % CI 0.55–0.79) and cancer-specific mortality (0.74, 0.61–0.90) were significantly lower in patients receiving platinum–taxane combination as compared to those without chemotherapy. Among patients with late-stage ovarian cancer, risks of mortality were significantly reduced in patients who received both platinum and taxane (0.38, 0.36–0.41 for all-cause mortality; 0.40, 0.37–0.42 for cancer-specific mortality). Dose–response relationship appeared strong within each of the three chemotherapy regimens. These results and trends were almost identical in the matched cohort. Platinum–taxane combination chemotherapy and platinum-based chemotherapy without taxane were effective in prolonging survival with a significant dose–response relationship among patients with late-stage ovarian cancer. Among those with early stage tumors, platinum–taxane combination appeared more effective than other chemotherapy regimens.
