Adjuvant external beam radiotherapy combined with brachytherapy for intermediate-risk cervical cancer.

ABSTRACT

OBJECTIVE: Patients with intermediate-risk cervical cancer receive external beam radiotherapy (EBRT) as adjuvant treatment. It is commonly administered with brachytherapy without proven benefits. Therefore, we evaluated the frequency of brachytherapy use, the doses for EBRT administered alone or with brachytherapy, and the overall survival impact of brachytherapy in patients with intermediate-risk, early-stage cervical cancer. METHODS: This retrospective cohort study was performed using data collected from the National Cancer Database. Patients diagnosed with cervical cancer from 2004 to 2019 who underwent a radical hysterectomy and lymph node staging and had disease limited to the cervix but with tumors larger than 4 cm or ranging from 2 to 4 cm with lymphovascular space invasion (LVSI) were included. Patients with distant metastasis or parametrial involvement were excluded. Patients who underwent EBRT alone were compared with those who also received brachytherapy after 21 propensity score matching. RESULTS: In total, 1174 patients met the inclusion criteria, and 26.7% of them received brachytherapy. After 21 propensity score matching, we included 620 patients in the EBRT group and 312 in the combination treatment group. Patients who received brachytherapy had higher equivalent doses than those only receiving EBRT. Overall survival did not differ between the two groups (hazard ratio (HR) 0.88 (95% confidence interval (CI), 0.62 to 1.23]; p=0.45). After stratification according to tumor histology, LVSI, and surgical approach, brachytherapy was not associated with improved overall survival. However, in patients who did not receive concomitant chemotherapy, the overall survival rate for those receiving EBRT and brachytherapy was significantly higher than that for those receiving EBRT alone (HR, 0.48 (95% CI, 0.27 to 0.86]; p=0.011). CONCLUSION: About one-fourth of the study patients received brachytherapy and EBRT. The variability in the doses and radiotherapy techniques used highlights treatment heterogeneity. Overall survival did not differ for EBRT with and without brachytherapy. However, overall survival was longer for patients who received brachytherapy but did not receive concomitant chemotherapy.