IMPORTANCE: Optimal adjuvant treatment for patients with intermediate-risk cervical cancer remains controversial, and the benefit of adding chemotherapy to radiotherapy in this population is uncertain. OBJECTIVE: To evaluate whether adjuvant chemoradiotherapy is associated with improved overall survival compared with radiotherapy alone in patients with intermediate-risk cervical cancer. Secondary objectives included identifying clinical factors associated with the use of chemoradiotherapy. DESIGN, SETTING, AND PARTICIPANTS: A cohort study was conducted at Commission on Cancer-accredited centers across the US using prospectively collected data from the National Cancer Database that focused on patients with a diagnosis of 2018 International Federation of Gynecology and Obstetrics stage IB cervical carcinoma (squamous cell carcinoma, adenosquamous carcinoma, or adenocarcinoma) of intermediate risk who were undergoing adjuvant radiotherapy treatment after radical hysterectomy from January 2010 through December 2020. Missing variables were multiple imputed, and propensity score matching (1:1) was performed to balance baseline characteristics. A Kaplan-Meier analysis and proportional hazard models were used to compare the hazard of death between the groups. EXPOSURE: Adjuvant radiotherapy alone vs concurrent chemoradiotherapy. MAIN OUTCOME AND MEASURE: The primary outcome was time to death or last follow-up. RESULTS: A total of 1116 patients (mean [SD] age, 47 [12] years) were identified, of whom 486 (43.5%) received concurrent chemoradiotherapy. Chemotherapy was administered more frequently among those with adenocarcinoma or adenosquamous histology compared with squamous cell carcinoma (risk ratio [RR], 1.26
95% CI, 1.10-1.44) and those with tumors larger than 4 cm (compared with tumors measuring 2-4 cm
RR, 1.31
95% CI, 1.14-1.51). Propensity score matching yielded a cohort of 868 patients with balanced covariates. Patients who received chemoradiotherapy had similar overall survival (5- year survival, 87%) as those who received radiotherapy alone (5-year survival, 87%
hazard ratio, 0.85
95% CI, 0.59-1.23
P = .38). There were no significant differences in survival associated with chemotherapy receipt among subgroups defined by tumor size, histology, presence of lymphovascular space invasion, surgical approach, or receipt of adjuvant brachytherapy. CONCLUSIONS AND RELEVANCE: The results of this cohort study suggest that adding chemotherapy to radiotherapy was not associated with improved overall survival for patients with intermediate-risk cervical cancer.