Survival Benefit of Adjuvant Brachytherapy After Hysterectomy With Positive Surgical Margins in Cervical Cancer

Abstract

We evaluated the use of brachytherapy (BT) in addition to external beam radiation therapy (EBRT) and the resulting effect on survival in patients with cervical cancer after hysterectomy with positive surgical margins. Patients with cervical cancer diagnosed from 2004 to 2015 who underwent hysterectomy followed by adjuvant EBRT were identified using the National Cancer Database. Only patients with positive surgical margins were included for analysis. Logistic regression was used to evaluate predictors of BT use and for propensity score matching. Survival was compared between patients receiving EBRT alone and those receiving EBRT combined with BT for adjuvant treatment. Survival analysis using log-rank test and Cox proportional hazards modeling was performed in the overall and propensity score-matched cohorts. We identified 1719 patients who underwent hysterectomy with positive surgical margins followed by adjuvant radiation therapy, of whom 778 (45.3%) received additional BT. Predictors of increased receipt of BT included age >55years, private rather than government insurance, radiation treatment duration ≥7weeks, EBRT dose ≥4500cGy, and time between radiation and surgery ≤9weeks. With a median follow-up of 3.8years, 3-year overall survival was 79.4% in patients receiving BT compared with 71.9% in patients receiving EBRT alone (log-rank P<.001). On multivariate analysis, EBRT and BT were associated with significantly improved survival (hazard ratio 0.77; 95% confidence interval 0.64-0.92; P=.003) compared with EBRT alone. The survival benefit of combining EBRT and BT persisted on propensity score-matched analysis (log-rank P=.005). In women with positive margins after hysterectomy for cervical cancer, the combination of EBRT and BT showed significantly improved overall survival compared with EBRT alone. However, only 45.3% of patients in our cohort received BT.