Radiotherapy with or without misonidazole for patients with stage IIIB or stage IVA squamous cell carcinoma of the uterine cervix: preliminary report of a Radiation Therapy Oncology Group randomized trial.

Between August 1980 and November 1984, 119 patients with FIGO Stage IIIB or IVA squamous cell carcinoma of the uterine cervix were randomized to receive radiation therapy (4600 cGy pelvis plus 1000 cGy parametrial boost) followed by intracavitary or external boost to the primary with or without misonidazole (MISO) (400 mg/m2 daily 2 to 4 hours prior to radiation therapy). Patients in the two treatment groups were evenly distributed with respect to stratification variables including stage, Karnofsky Performance score, and positivity of para-aortic nodes. Eighty-nine percent of patients had Stage IIIB disease and 88% had a Karnofsky score of 80 or better. Seventy-five percent of patients treated with radiation therapy alone and 79% of patients treated with radiation therapy plus MISO received a boost via intracavitary application. Life threatening (Grade 4) complications occurred in 5 patients receiving radiation therapy alone and one patient receiving radiation therapy plus MISO. MISO toxicity (Grade 3) was limited to severe nausea and vomiting in two patients. With 119 evaluable patients and a median follow-up of 33 months, 64% of patients receiving radiation therapy alone are alive at 18 months compared with 54% for patients assigned to radiation therapy plus MISO. The median survival for patients treated with radiation therapy alone and radiation therapy plus MISO was 1.9 years and 1.6 respectively. At this point in the study the difference in survival is inconsistent with the hypothesis of an improvement associated with MISO. There have been 23 deaths among the 49 patients treated with radiation therapy plus MISO who have been followed for at least 18 months compared with 17 deaths in 48 patients treated with radiation therapy alone. The chance of observing this number of deaths with radiation therapy plus MISO if the addition of MISO improves survival by 10 to 20% is 0.003 and less than 0.001, respectively. The addition of MISO to radiation failed to improve survival for these patients. The results cannot be explained by an uncharacteristically high survival on the radiation therapy alone arm or by an imbalance in the distribution of prognostic factors. Local-regional control remains a problem in the management of patients with advanced cervical carcinoma. More effective and less toxic radiosensitizing agents are needed.