The role of postoperative local or regional irradiation in the treatment of stage I ovarian cancer.

Histological grade and cell type were major prognostic factors in a retrospective study of 63 patients with Stage I epithelial carcinoma of the ovary. Grading by architectural pattern seemed to predict relapse better than cytological grading. With serous, mucinous, and endometrioid cystadenocarcinomas, relapses increased with higher grades. Relapse occurred in none of 18 tumors of borderline malignancy, 2 of 27 (7%) with Grade I or II tumor, and 4 of 6 (67%) with Grade III. The upper abdomen and pelvis were both at risk. Because most recurrences were limited to the peritoneal surface in Grade III serous, mucinous, and endometrioid carcinoma, local and regional radiation therapy are justified; postoperative therapy is not recommended for borderline or Grade I tumors unless ascites or cytological evidence of peritoneal disease is present. Clear-cell carcinoma was uncommon and unfavorable; of 12 cases, 5 involved relapse, with 3 recurrences developing outside the abdomen.