Long-Term Follow-Up of a Randomized Trial Comparing Concurrent Single Agent Cisplatin, Cisplatin-Based Combination Chemotherapy, or Hydroxyurea During Pelvic Irradiation for Locally Advanced Cervical Cancer: A Gynecologic Oncology Group Study

Abstract

We report the long-term survival and toxicity of a randomized phase III study comparing cisplatin alone with cisplatin, flurouracil, and hydroxyurea versus hydroxyurea concurrent with pelvic irradiation for patients with locally advanced cervical cancer with pathologically negative para-aortic nodes. Comparisons of progression-free (PFS) and overall survival (OS) between treatment arms utilized Kaplan-Meier and log-rank statistics. Relative risk estimates adjusting for prognostic factors were determined using the Cox proportional hazards regression model. Pearson's 2 test was used to assess differences in adverse events. The analysis included 526 patients. The median follow-up among surviving patients was 106 months. Consistent with the original report, improvement in PFS and OS was evident for both cisplatin-containing arms compared with hydroxyurea (P < .001). Analogous results were seen for stage IIB and for stage III disease (each P < .025). The relative risk of progression of disease or death was 0.57 (95% CI, 0.43 to 0.75) with cisplatin and 0.51 (95% CI, 0.38 to 0.67) with cisplatin-based combination chemotherapy compared with hydroxyurea. Among 518 patients who received radiation, acute (grade 3 or 4) gastrointestinal or urologic toxicities occurred in 66 with cisplatin (19.1%) and 29 with hydroxyurea (16.8%). Delayed radiation toxicity occurred in six patients who received cisplatin (1.7%) and two who received hydroxyurea (1.2%; P = .680). Cisplatin-based chemotherapy during pelvic radiation therapy improves long-term PFS and OS among locally advanced cervical cancer patients collectively and for stage IIB and III disease, individually. There was no observed increase in late toxicity with cisplatin-based chemoradiotherapy.