The morbidity of treatment for patients with Stage I endometrial cancer: results from a randomized trial.

Purpose: To compare the treatment complications for patients with Stage I endometrial cancer treated with surgery and pelvic radiotherapy (RT) or surgery alone in a multicenter randomized trial.
Methods and Materials: The Postoperative Radiation Therapy in Endometrial Carcinoma (PORTEC) trial included patients with endometrial cancer confined to the uterine corpus, either Grade 1 or 2 with more than 50% myometrial invasion, or Grade 2 or 3 with less than 50% myometrial invasion. Surgery consisted of an abdominal hysterectomy and oophorectomy, without lymphadenectomy. After surgery, patients were randomized to receive pelvic RT (46 Gy), or no further treatment. A total of 715 patients were randomized. Treatment complications were graded using the French-Italian glossary.
Results: The analysis was done at a median follow-up duration of 60 months. 691 patients were evaluable. Five-year actuarial rates of late complications (Grades 1-4) were 26% in the RT group and 4% in the control group (p < 0.0001). Most were Grade 1 complications, with 5-year rates of 17% in the RT group and 4% in the control group. All severe (Grade 3-4) complications were observed in the RT group (3%). Most complications were of the gastrointestinal tract. The symptoms resolved after some years in 50% of the patients. Grade 1-2 genitourinary complications occurred in 8% of the RT patients, and 4% of the controls. Bone complications occurred in 4 RT patients (1%). Seven patients (2%) discontinued their RT due to acute RT-related symptoms. Patients with acute morbidity had an increased risk of late RT complications (p = 0.001). The 4-field box technique was associated with a lower risk of late complications (p = 0.06).
Conclusion: Pelvic RT increases the morbidity of treatment in Stage I endometrial cancer. In the PORTEC trial, severe complications occurred in 3% of treated patients, and over 20% experienced mild (mostly Grade 1) symptoms. Patients with acute RT-related morbidity had an increased risk of late complications. As pelvic RT in Stage I endometrial carcinoma was shown to significantly reduce the rate of locoregional recurrence, but without a survival benefit, its use in the adjuvant setting requires careful patient selection (treating those at increased risk of relapse), and the use of treatment schemes with the lowest risk of morbidity.