Effects of irradiation on mixed müllerian tumors of the uterus.

A retrospective study of 54 patients with histologically proven malignant mixed müllerian tumors of the uterus was undertaken with main emphasis on the evaluation of the effects of irradiation on pelvic tumor control. The tumors were staged according to the FIGO classification for endometrial carcinoma and 24 were classified as Stage I, 10 as Stage II, 13 as Stage III and seven as Stage IV. Patients with Stage I and II were treated with surgery alone (9 patients, three surviving) or preoperative intracavitary irradiation (13 patients, eight surviving) or preoperative combination of intracavitary and external irradiation (12 patients, six surviving). Five patients with Stage III and IV were treated with surgery alone, two were treated with a combination of irradiation and surgery and 11 with radiation alone. None of these patients survived. In seven patients showing no residual tumor in the uterine specimen after irradiation, no pelvic failures were noted, whereas seven of 17 (41.2%) with residual tumor developed pelvic recurrences. In patients with Stage I treated with surgery alone, three out of six recurred in the pelvis whereas only three of 17 (17%) receiving preoperative irradiation developed pelvic recurrences. However, in Stage II six of eight patients treated with preoperative irradiation failed in the pelvis. Correlation with the doses of irradiation given to the uterus or the pelvic lymph nodes indicate that with doses below 5000 rads a significantly higher number of pelvic recurrences take place, whereas these are uncommon with doses over 6000 rads. The difference in pelvic recurrences between dosage levels is not, however, statistically significant. It is suggested that patients with Stage I and II malignant mixed müllerian tumors of the uterus should be treated with preoperative radiation and total hysterectomy with bilateral salpingo-oophorectomy. Patients with more advanced disease have extremely poor prognosis and should be treated with radiation therapy alone. This tumor has a high propensity to spread through lymphatics and hematogenous metastases are seen in approximately 75% of the patients. Because of this dissemination, significant improvements in survival rate will not be seen until effective cytotoxic agents are available.