Impact of care by gynecologic oncologists on primary ovarian cancer survival: A population-based study

Timely treatment of epithelial ovarian cancer (EOC) by gynecologic oncologists (GOs) with a combination of surgery and/or chemotherapy has been advocated. Nonetheless, some patients are not assessed by GOs prior to starting their treatment or have surgery by non-GOs. This study aims to determine trends over time in non-mucinous EOC care and to evaluate the impact of care on survival.Using province-wide administrative data, patients diagnosed with non-mucinous EOC between 2007 and 2018 were identified. Multivariate Cox proportional hazards regression models were used to evaluate the impact of GO assessment prior to initiating treatment or having surgery done by a non-GO on mortality.A total of 10,086 EOC patients were included between 2007 and 2018. During the study period, there was an 8% increase in GO assessment (79% in 2007 to 87% in 2018-19, p ≤ 0.001) and a 19% increase in surgeries performed by GOs (69% in 2007 to 88% in 2018-19, p ≤ 0.001). On multivariate analysis, there was an increased hazard of all-cause mortality for patients not assessed by GOs before first treatment (Hazard ratio (HR): 1.61; 95% CI 1.46-1.79). There was an increased hazard of all-cause mortality if ovarian cancer surgery was performed by non-GOs (HR 2.03; 95% CI 1.80-2.30).Assessment by GO before starting initial treatment is associated with improved survival in women with non-mucinous EOC as the type of surgeon performing primary ovarian cancer surgery. Assessment by GO for all patients with new or suspected ovarian cancer diagnosis before initiation of primary treatment should be advocated.