Clinical trial enrollment during first course of gynecologic cancer treatment and survival

Among gynecologic cancer patients, it is unclear whether participation in clinical trials impacts survival outcomes. In addition, given the known racial and ethnic disparities in gynecologic cancer trial enrollment, it is important to assess whether clinical trial enrollment is similarly related to overall survival among racial and ethnic minorities. Therefore, we examined associations between clinical trial enrollment and overall survival and potential effect modification by race/ethnicity and cancer site among gynecologic cancer patients.

We used the National Cancer Database to identify women diagnosed with a cervical, ovarian, or uterine cancer from 2004 to 2020 (N = 861,817). Race/ethnicity categories included American Indian/Alaska Native, Asian, Black, Hispanic (any race), Native Hawaiian/Pacific Islander, and White. We used stratified Cox proportional hazards regression to estimate univariable and multivariable-adjusted hazard ratios and 95% confidence intervals for associations of clinical trial enrollment and overall survival. Effect modification by race/ethnicity and cancer site was assessed with multiplicative interaction terms in separate models.

Among 861,817 gynecologic cancer patients included, less than 0.1% were enrolled in a clinical trial (n = 881). Median follow-up was 56.0 months (range 0.03-229.4 months). Clinical trial enrollment was related to improved overall survival among gynecologic cancer patients in the overall study population (hazard ratio = 0.90, 95% confidence interval = 0.82-0.99). Neither race/ethnicity (p = 0.34) nor cancer site (p = 0.09) modified the association.

Despite the low clinical trial enrollment prevalence, enrollment was associated with improved outcomes for gynecologic cancer patients. These findings are important in demonstrating that participation in clinical trials, regardless of therapeutic treatment assignment, is related to better outcomes.