Objective: Because stage IIIC corpus cancer is a heterogeneous substage, the outcomes of patients with stage IIIC disease were assessed according to the extent of extrauterine disease.

Methods: From 1984 through 1993, 51 patients with surgical stage IIIC corpus cancer were treated at our institution; 5 patients had tumors with nonendometrioid histologic features and were excluded from the analyses. Of the 46 patients with endometrioid carcinoma, 22 had lymph nodes as the only site of extrauterine disease (stage IIIC(0)) and 24 also had peritoneal cytologic, uterine serosal, adnexal, or vaginal involvement or a combination of these (stage IIIC(ab)). The mean number of lymph nodes removed was 18 pelvic and 8 aortic nodes. Median follow-up for surviving patients was 84 months.

Results: Patients with stage IIIC(0) cancer had a 5-year cause-specific survival (CSS) of 72% and a 5-year recurrence-free survival (RFS) of 68%, and those with stage IIIC(ab) had a CSS of 33% and an RFS of 25% (P < 0.01). Of the 22 patients with stage IIIC(0) endometrioid cancer, 21 had adjuvant radiotherapy (1 also received chemotherapy) and 1 was not treated. Relapse occurred in 7 (32%) patients, with only 1 having an initial failure component outside the node-bearing areas (lung). Of the 24 patients with stage IIIC(ab) cancer, 16 received adjuvant radiotherapy (1 had concomitant chemotherapy), 2 had chemotherapy, 4 had hormonal therapy, and 2 were not treated. We observed 16 recurrences (67%). Of the 14 patients with known initial sites of failure, 9 had an extranodal failure component.

Conclusion: Assessment of CSS, RFS, and sites of relapse suggests that FIGO surgical stage IIIC endometrioid corpus cancer includes two distinct and readily separable subgroups: (1) stage IIIC(0), nodal involvement only, and (2) stage IIIC(ab), nodal plus cytologic, uterine serosal, adnexal, or vaginal involvement, or a combination of these. Our results also suggest that different treatment strategies are needed for these subgroups.