Therapeutic outcome and relation of acute and late side effects in the adjuvant radiotherapy of endometrial carcinoma stage I and II.

Background and Purpose: Adjuvant radiotherapy is the standard treatment for endometrial carcinoma. However, until now there has been no clear indication that radiotherapy in that setting improves survival. This calls for critical assessment of the relation between the expected benefit and the number and severity of postradiotherapeutic side effects.
Material and Methods: In a retrospective study 159 consecutive patients with stage I and II endometrial carcinoma were treated with external radiotherapy and vaginal brachytherapy after hysterectomy and bilateral salpingoophorectomy (no surgical lymph node staging). Recurrence rates, survival and side effects were evaluated, in particular with regard to the relation of acute and late toxicity.
Results: Five percent of all patients developed a recurrence either in the abdomen or at distant locations. No pelvic relapses were diagnosed. Five-year relapse-free survival was 92% for stage IA + B, 84% for stage IC, and 79% for stage II disease. Acute toxicity was seen in 65.4% of patients, all grade 1 or 2, late toxicity grade 1 or 2 in 18.8%, grade 3 or 4 complications in 1.8%. The estimated 5-year freedom from late toxicity was 76.8%. Seventy-seven percent of all patients with treatment interruptions or premature end of therapy experienced late injury. In ten of 33 patients with late sequelae there was no free interval between early and late toxicity. No relation of radiation technique/fractionation and the rate of side effects was noticed.
Conclusions: Adjuvant radiotherapy leads to excellent pelvic control, with few serious complications. Major acute toxicity shows significant correlation with the incidence of severe late injury, which we suggest to classify in part as consequential late effects.