Radiation therapy with or without weekly cisplatin for bulky stage 1B cervical carcinoma: follow-up of a Gynecologic Oncology Group trial

Objective: The objective of the study was to confirm that concurrent cisplatin (CT) with radiation therapy (RT) is associated with improved long-term progression-free survival (PFS) and overall survival (OS), compared with RT alone in stage IB bulky carcinoma of the cervix, when both groups' therapy is followed by hysterectomy. Study design: Three hundred seventy-four patients entered this trial. There were 369 evaluable patients; 186 were randomly allocated to receive RT alone and 183 to receive CT plus RT. Radiation dosage was 45 Gray (Gy) in 20 fractions followed by low dose-rate intracavitary application(s) of 30 Gy to point A. Chemotherapy consisted of intravenous cisplatin 40 mg/m(2) every week for up to 6 weekly cycles. Total extrafascial hysterectomy followed the completion of RT by 6-8 weeks. Results: Preliminary results have been published, at which time there were 292 censored observations, and median duration of follow-up was only 36 months. Patient and tumor characteristics were well balanced between the regimens. The median patient age was 41.5 years; 81% had squamous tumors; 59% were white. Median follow-up is now 101 months. The relative risk for progression was 0.61 favoring CT plus RT (95% confidence interval [CI] 0.43 to 0.85, P < .004). At 72 months, 71% of patients receiving CT plus RT were predicted to be alive and disease free when adjusting for age and tumor size, compared with 60% of those receiving RT alone. The adjusted death hazard ratio was 0.63 (95% CI 0.43 to 0.91, P = .015) favoring CT plus RT. At 72 months, 78% of CT plus RT patients were predicted to be alive, compared with 64% of RT patients. An increased rate of early hematologic and gastrointestinal toxicity was seen with CT plus RT. There was no detectable difference in the frequency of late adverse events. Conclusion: Concurrent weekly cisplatin with RT significantly improves long-term PFS and OS when compared with RT alone. Serious late effects were not increased. The inclusion of hysterectomy has been discontinued on the basis of another trial. Pending further trials, weekly cisplatin with radiation is the standard against which other regimens should be compared.