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

Purpose 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. Patients and Methods 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 χ2 test was used to assess differences in adverse events. Results 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). Conclusion 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.