Use and Duration of Chemotherapy and Its Impact on Survival in Early-stage Ovarian Cancer

Objective: Although 5-year survival for early-stage ovarian cancer is favorable, prognosis at recurrence is poor, necessitating appropriate initial management. We examined the patterns of care and the impact of the duration of chemotherapy on survival for women with early-stage ovarian cancer.

Methods: We used the SEER-Medicare database to identify women ≥ 65 years of age with stage I ovarian cancer diagnosed from 1992 to 2009. Patients were categorized as low-risk (non-clear cell histology, stage IA or IB, grade 1 or 2) or high-risk (clear cell histology, grade 3, or stage IC). We used multivariable logistic regression models to determine predictors of chemotherapy use and duration and Cox proportional hazards models to evaluate the effect of chemotherapy use and duration on survival.

Results: We identified 1394 patients. Among low-risk patients, 32.9% received adjuvant chemotherapy and the use of chemotherapy increased with time. Among high-risk patients, 71.9% received adjuvant chemotherapy; 44.2% had ≤ 3 months of treatment, and 55.8% had > 3 months of treatment. Older patients were less likely to receive chemotherapy, while those with higher stage and grade were more likely to receive chemotherapy (P<0.05 for all). Among high-risk patients, the duration of chemotherapy did not impact overall (HR=0.93, 95% CI, 0.67-1.27) or cancer specific (HR=0.93; 95% CI, 0.61-1.42) survival.

Conclusions: Among early-stage ovarian cancer patients, practice patterns are widely divergent. Extended duration chemotherapy does not appear to impact survival for women with high-risk disease.