Optimal use of radiotherapy in the definitive treatment of non-bulky IB-IIA cervical cancer: A population-based long-term survival analysis.

PURPOSE Although current clinical guidelines recommend surgery or radiotherapy for non-bulky IB-IIA cervical cancer, clinical data supporting the curative role of radiotherapy in the early-stage disease are insufficient. We evaluated the prognostic implications of definitive radiotherapy and determined its optimal use in clinical practice. METHODS Patients with non-bulky (<4 cm) IB-IIA cervical cancer who underwent hysterectomy or primary radiotherapy between 1988 and 2015 were identified from the Surveillance, Epidemiology, and End Results database. Based on the use of brachytherapy and/or chemotherapy, the primary radiotherapy group was classified into three cohorts: hysterectomy vs. radiotherapy overall, with/without brachytherapy and/or chemotherapy (cohort A); radiotherapy and brachytherapy with/without chemotherapy (patients with external beam radiation alone were excluded, cohort B); radiotherapy with brachytherapy and chemotherapy (patients who did not receive chemotherapy were additionally excluded, cohort C). Disease-specific survival (DSS) after hysterectomy was compared to that after primary radiotherapy in each cohort. RESULTS Among the 9,391 initially identified patients, 1,762, 1,244, and 750 patients were classified into cohorts A, B, and C, respectively, after propensity score matching. In cohort A, DSS after primary radiotherapy was inferior to that after hysterectomy (P = 0.001). In cohort B, a trend toward differential survival in favor of hysterectomy was observed with marginal significance (P = 0.061). However, in cohort C, DSS after primary radiotherapy was not significantly different to that after hysterectomy (P = 0.127). According to hazard rate function plots, patients receiving external beam radiation alone had an increased short-term risk of disease-specific mortality, whereas patients without evidence of chemotherapy had a distinct late risk surge at approximately 15 years of follow-up. CONCLUSION Optimizing radiotherapy methods with brachytherapy and the use of chemotherapy should be considered for the long-term curative efficacy of primary radiotherapy for non-bulky IB-IIA cervical cancer. Further studies are warranted to corroborate our results.