A management program for FIGO stage I-II nonserous, nonclear-cell adenocarcinomas was evaluated. Histopathology and DNA ploidy were used to estimate postoperatively the risk of progression or death of disease and to tailor treatment. The patient material was a population-based consecutive cohort of all women with endometrial cancer in the Southern Swedish Health Care Region diagnosed between June 1993 and June 1996 (n = 553). Of these, 335 were eligible for the management program. Patients estimated to be at low risk were treated by surgery only, while high-risk patients also received vaginal brachytherapy. A large low-risk group consisting of 84% (n = 283) of the patients with an estimated disease-specific 5-year survival of 96% (95% CI = 93-98%) was identified. The high-risk group (n = 52, 16%) showed a worse outcome with an 80% 5-year disease-specific survival (95% CI = 65-89%). The difference in survival between the groups was highly significant (P < 0.0001). Half of the progressions were distant in the high-risk group. Although there is a clear indication for adjuvant therapy for this group, locoregional radiotherapy could be expected to fail in cases with distant progression. Thus, effective systemic treatments need to be developed. Low-risk patients, constituting the majority (84%) of the patients, can be safely treated by surgery only.