Adenocarcinoma of the endometrium treated with combined irradiation and surgery: study of 437 patients.

ABSTRACT

PURPOSE: To identify prognostic factors and treatment toxicity in a series of operable endometrial adenocarcinomas. METHODS AND MATERIALS Between November 1971 and October 1992, 437 patients (pts) with endometrial carcinoma, staged according to the 1988 FIGO staging system (225 Stage IB, 107 Stage IC, 4 Stage IIA, 35 Stage IIB, 30 Stage IIIA, 6 Stage IIIB, and 30 Stage IIIC), underwent total abdominal hysterectomy and bilateral salpingo-oophorectomy without (n = 140) or with (n = 297) pelvic lymph node dissection. The chronology of adjuvant RT was not randomized and depended on the usual practices of the surgical teams. Seventy-nine pts (Group I) received preoperative low-dose-rate uterovaginal brachytherapy (mean dose [MD] 57 Gy). Three hundred fifty-eight pts (Group II) received postoperative RT. One hundred ninety-six pts received low-dose-rate vaginal brachytherapy alone (MD 50 Gy). One hundred fifty-eight pts had external beam pelvic RT (MD 46 Gy) followed by low-dose-rate vaginal brachytherapy (MD 17 Gy). Four pts had external beam pelvic RT alone (MD 47 Gy). The mean follow-up from the beginning of treatment was 128 months. RESULTS: The 10-year disease-free survival rate was 86%. From 57 recurrences, only 12 were isolated locoregional recurrences. The independent factors decreasing the probability of disease-free survival were as follows histologic type (clear-cell carcinoma, p = 0.038), largest histologic tumor diameter >3 cm (p = 0.015), histologic grade (p = 0.008), myometrial invasion > 1/2 (p = 0.005), and 1988 FIGO staging system (p = 9.10(-8)). In Group II, the addition of external beam pelvic RT did not seem to independently improve vaginal or pelvic control. The postoperative complication rate was 7%. The independent factors increasing the risk of postoperative complications were stage FIGO (p = 0.02) and pelvic lymph node dissection (p = 0.011). The 10-year rate for Grade 3 and 4 late radiation complications according to the LENT-SOMA scoring system was 3.1%. External beam pelvic RT independently increased the rate for Grade 3 and 4 late complication (RR 5.6, p = 0.0096). CONCLUSION: Postoperative external beam pelvic RT increases the risk of late radiation complications. After surgical and histopathologic staging with pelvic lymph node dissection, in subgroup of "intermediate-risk" patients (Stage IA Grade 3, IB-C and II), postoperative vaginal brachytherapy alone is probably sufficient to obtain a good therapeutic index. Results for patients with Stage III tumor are not satisfactory.