Cisplatin Chemoradiotherapy vs Radiotherapy in FIGO Stage IIIB Squamous Cell Carcinoma of the Uterine Cervix A Randomized Clinical Trial

IMPORTANCE The evidence for concurrent chemoradiotherapy (CT-RT) in International Federation of Gynecology and Obstetrics (FIGO) stage IIIB squamous cell carcinoma of the uterine cervix is not robust. This study reports the final results of a randomized clinical trial of concurrent cisplatin-based CT-RT and radiotherapy alone (RT) in women with FIGO stage IIIB squamous cell carcinoma of the uterine cervix. OBJECTIVE To investigate the benefit of concurrent CT-RT in FIGO stage IIIB squamous cell carcinoma of the uterine cervix. DESIGN, SETTING, AND PARTICIPANTS This phase 3 open-label randomized clinical trial accrued 850 women in Mumbai, India, between July 7, 2003, and September 22, 2011. Of 2121 screened, 850 women with FIGO stage IIIB squamous cell carcinoma of the uterine cervix suitable for concurrent cisplatin chemotherapy were randomly assigned to CT-RT and RT using block randomization (1:1). The data were updated for a minimum follow-up period of 5 years until December 2016. The final analyses were performed in February and March 2017. This single-institution study was conducted at a tertiary cancer center setting. INTERVENTIONS Randomization to receive RT (RT arm), comprising a combination of external beam RT (50 Gy in 25 fractions over 5 weeks) and brachytherapy, or to receive in addition to the same RT concurrent weekly cisplatin chemotherapy (40 mg/m(2) per week) (CT-RT arm). MAIN OUTCOMES AND MEASURES The primary end point was 5-year disease-free survival (DES), defined as the time between the date of randomization and the date of any recurrence or death (whichever occurred first) in the intent-to-treat population. RESULTS This trial included 424 women assigned to CT-RT (mean [SD] age, 494 [7.9] years) and 426 women assigned to RT (mean [SD] age, 49.3 [7.9] years). At a median follow-up of 88 months (interquartile range, 61.3-113.1 months), there were 222 recurrences and 213 deaths in the CT-RT arm and 252 recurrences and 243 deaths in the RT arm. The 5-year DFS was significantly higher in the CT-RT arm (52.3%; 95% Cl, 52.2%-52.4%) compared with the RT arm (43.8%; 95% Cl, 43.7%-43.9%), with a hazard ratio for relapse or death of 0.81 (95% Cl, 0.68-0.98) (P = .03). Similarly, the 5-year overall survival (OS) was significantly higher in the CT-RT arm (54.0%; 95% Cl, 53.9%-54.1%) compared with the RT arm (46.0%; 95% Cl, 45.9%-46.1%), with a hazard ratio for death of 0.82 (95% Cl, 0.68-0.98; P = .04). After adjusting for prognostic factors, CT-RT continued to be significantly superior to RT for DFS and OS. There was a higher incidence of acute hematological adverse effects in the CT-RT arm. CONCLUSIONS AND RELEVANCE Chemoradiotherapy using weekly cisplatin results in significantly better DES and OS compared with RT in women with stage IIIB squamous cell carcinoma of the uterine cervix. This study provides level 1 evidence in the largest clinical trial reported so far in favor of concurrent weekly cisplatin chemotherapy in this setting.