Clinical stage I endometrial cancer: results of adjuvant irradiation and patterns of failure.

A retrospective analysis is reported in 858 patients with clinical Stage I carcinoma of the endometrium treated definitively from January 1960 through December 1986 with combined irradiation and total abdominal hysterectomy and bilateral salpingo-oophorectomy (TAH-BSO). Most patients received a preoperative intracavitary insertion (2500-4000 mgh to the uterus with Heyman capsules and tandem and 6500 cGy surface dose to the upper vagina) followed by a TAH-BSO within 6 weeks. Some patients received postoperative external beam irradiation (2000 cGy whole pelvis and an additional 3000 cGy to the parametria, with a midline stepwedge) when deep myometrial invasion was present. Occasionally patients were treated with preoperative external beam irradiation (2000 cGy whole pelvis) and intracavitary insertion. The 5-year overall survival for all patients was 84.0% compared to an expected survival of 88.8%. The 5-year progression-free survivals were 92% for FIGO clinical Stage IA and 86% for stage IB (p = 0.12). The dose to the uterine fundus from the preoperative intracavitary insertion was found to have a significant correlation with progression-free survival in patients with grade 3 tumors. Those receiving less than 2500 mgh to the uterine cavity had a 48.9% 5-year progression-free survival compared to 62.7% for 2500-3500 mgh and 87.4% for those receiving greater than 3500 mgh. Analysis of sites of failure showed that less than 1% (7/858) failed in the pelvis alone, 3% (30/858) in the pelvis combined with distant sites, and 7% (60/858) developed distant metastasis only. The lateral pelvic sidewall was the most common site of failure within the pelvis (20/37) and intraperitoneal failures (28/90) and lung (21/90) were the most common sites of distant metastasis. The overall severe (grades 2, 3, and 4) complication rate was 2.7% (23/858).