Adoption and impact of concurrent chemoradiation therapy for vaginal cancer: a National Cancer Data Base (NCDB) study.

Background: Vaginal cancer is an uncommon entity for which concurrent chemoradiation (CCRT) may be used based on small retrospective series and extrapolation from cervical cancer. We explored the adoption rate of CCRT and determined its impact on survival.

Methods: Patients entered into the National Cancer Data Base (NCDB) diagnosed with vaginal cancer from 1998 to 2011 who received definitive radiation therapy were included. Univariate/multivariable exploratory analyses of factors associated with CCRT were performed. Log-rank test and Cox proportional hazards modeling identified the contribution of CCRT on survival.

Results: Of the 13,689 patients identified, 8222 (60.1%) received radiation therapy. Of these, 3932 (47.8%) received CCRT and its use increased from 20.8% to 59.1% (1998-2011). Of the 23 patient, disease, facility, and treatment factors, 13 were significantly associated with patient outcomes and were entered into a binary logistic regression model. This evaluation revealed that younger age, larger tumor size, later year of diagnosis, higher facility volume, squamous histology, and higher stage (in order of increasing association) are independently associated with CCRT use. Median overall survival is longer with CCRT compared to radiation alone (56.2 vs. 41.2 months, p<0.0005). On multivariable analysis, younger age, higher facility volume, squamous histology, lower comorbidity score, CCRT, brachytherapy utilization and lower stage (in order of increasing association) are independently prognostic of improved survival.

Conclusions: Use of CCRT for patients with vaginal cancer has increased and is associated with a significant improvement in survival in this large, national cohort. CCRT should be integrated into treatment guidelines for vaginal cancer.