Background: Overall survival associated with National Comprehensive Cancer Network (NCCN) adjuvant chemotherapy treatment guideline using population-based surveillance data is limited. This study examined overall survival and compliance to the NCCN guideline for adjuvant chemotherapy.
Methods: The Midwest Ovarian Cancer Study was a collaborative project between 3 state cancer registries (Iowa, Kansas, and Missouri), Westat, and the Centers for Disease Control and Prevention. A standardized protocol was used to ascertain International Federation of Gynecology and Obstetrics (FIGO) stage-specific adjuvant chemotherapy. Primary epithelial ovarian cancers with FIGO stages IA/IB grade 3, IC, and II-IV with histologies 8000-8576 and 8930-9110 were included in this study. The Kaplan-Meier method was used to calculate survival functions. Adjusted hazard ratio (HR) was analyzed for all-cause mortality associated with NCCN compliance with adjuvant chemotherapy after adjusting for stage at diagnosis and comorbidity.
Results: Sixtynine percent (523 of 756 eligible) were compliant with NCCN guidelines. Compliance was significantly different by age at diagnosis and insurance type (both P < .0001). The overall survival was significantly different by age group, census tract median income, histologic subtype, and tumor grade (all P < .0001). The adjusted HR of noncompliance with adjuvant chemotherapy guideline was 3.2 (95% CI, 2.600-3.911).
Conclusions: Better overall survival in patients who had received NCCN-recommended adjuvant chemotherapy was confirmed.
Impact: The survival benefit was 7% higher over 4 years after diagnosis when considering FIGO stage-specific chemotherapy and the corresponding number of cycles. Using the chemotherapy data field that is collected by statewide cancer registries underestimated the overall survival.
Keywords: National Comprehensive Cancer Network guideline compliance; National Program of Cancer Registries; Surveillance, Epidemiology, and End Results Program; ovarian cancer; overall survival.