Toxicity, recurrence and survival after adjuvant radiotherapy treatment for FIGO stage I cancer of the endometrium

We conducted a retrospective observational study to determine the rate of toxicity, pattern of tumour recurrence and survival associated with radiotherapy treatment for FIGO stage I cancer of the endometrium. All patients had undergone definitive surgery and had been referred to the oncology department of the University Hospital Birmingham, U.K. Two hundred and forty-five women were included in the study; 228 patients were treated with radiotherapy; 160 had external beam radiation alone; 32 had vaginal vault brachytherapy alone; 36 patients had both modalities; and 17 patients were not given radiotherapy. There were nine cases of Grade 3 and 4 radiation reactions, of which four were acute, four were late and one was acute and late toxicity. The severity of both acute and late radiation effects was significantly associated with the delivery of vault brachytherapy (external beam radiotherapy alone compared with brachytherapy alone (1/158 vs 3/32; P=0.02). Thirty-four patients were diagnosed with tumour recurrence (11 distant, 14 local, 4 patients had both distant and local disease and 5 patients had recurrence diagnosed at the time of death). Patients who received no radiotherapy were at greater risk of local pelvic tumour recurrence (P<0.0001; hazard ratio [HR] 9.6, 95% confidence interval (CI) 3.5-26.3). Vaginal vault brachytherapy had no discernible effect on the pattern of tumour recurrence. Forty-six patients died during the follow-up period, 28 of these were attributable to carcinoma of the endometrium. There was no difference in survival between the four treatment groups (P=0.68). The overall 5-year survival rate in our study group was 89.6% (85.4-93.8%). In a proportional hazards model, tumour grade (HR 2.0 per level [1.25, 3.17]; P=0.004]) and age (HR 1.74 per 10 years [1.12, 2.69]; P=0.01) were the only factors found to have an independent influence on survival. This study suggests that, although pelvic radiation may not alter overall survival, it does reduce the risk of local disease recurrence. In this study population, vaginal vault brachytherapy using a vaginal stock/dobbie showed no additional benefits compared with external beam radiotherapy; it was, however, associated with a higher rate of both acute and late radiation effects. (C) 2003 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.