Incorporation of vaginal brachytherapy to external beam radiotherapy in adjuvant therapy for high-risk early-stage cervical cancer: A comparative study

Abstract

PURPOSETo examine trends, characteristics, and outcomes related to addition of vaginal brachytherapy (VBT) to external beam radiotherapy (EBRT) for adjuvant radiotherapy in high-risk early-stage cervical cancer. METHODS AND MATERIALSThis comparative study is a retrospective observational analysis of the National Cancer Institutes’ Surveillance, Epidemiology, and End Results Program. Surgically treated women with stage T1-2 cervical cancer who had high-risk factors (nodal metastasis and/or parametrial invasion) and received adjuvant radiotherapy from 2000 to 2018 were examined. Propensity score inverse probability of treatment weighting was used to assess the survival estimates for addition of VBT use. RESULTSAmong 2470 women with high-risk factors receiving EBRT, 760 (30.8%) had additional VBT. During the study period, there was an increasing trend of VBT use from 27.4% to 36.1% (p< 0.001). In a multivariable analysis, year of diagnosis and high-risk tumor factors: parametrial involvement, large tumor size, and use of chemotherapy remained independent characteristics associated with VBT use (all, p< 0.05). In propensity score-weighted models, VBT use with EBRT and EBRT alone had comparable overall survival (5-year rates 73.8% vs. 77.4%, hazard ratio [HR] 1.07, 95% confidence interval [CI] 0.92–1.25). Nonsignificant association was also observed in squamous or nonsquamous tumors, young or old age, low or high nodal ratio, chemotherapy use, and simple or radical hysterectomy (all, p> 0.05). Lastly, the addition of VBT was not associated with cervical cancer-specific survival (subdistribution-HR 1.15, 95% CI 0.94–1.41). CONCLUSIONSUtilization of VBT with EBRT for adjuvant radiotherapy in high-risk early-stage cervical cancer is increasing in the United States. Addition of VBT was associated with neither overall survival nor cancer-specific survival.