Objective Specific outcomes for early-stage ovarian endometrioid carcinoma (OEC) have not been well characterized. In addition, the benefit of any type of postsurgical therapy remains unclear. Our aims were to delineate (1) potential prognostic factors and (2) the impact of adjuvant treatment on survival in such patients.

Methods Women with FIGO stages I and II OEC referred to one of the centers of the British Columbia Cancer Agency from 1984 to 2008 were included in a retrospectively abstracted computerized database. Irradiation (abdominal-pelvic) in addition to chemotherapy (3 cycles of platinum combination) was to be given for stage IA/B, grade 2/3; stage IC, any grade; and stage II, any grade, except from 1989 to 1994 when irradiation was dropped from the paradigm for all patients. Univariate analysis and a multivariate analysis, using a decision tree analysis, were carried out of disease-free survival (DFS).

Results One hundred seventy-two patients were identified. Twelve percent were grade 3; 55%, 85%, and 89% of stages IA/B, IC, and II received postoperative adjuvant treatment. Five-year DFS was 95%, 84%, and 74% for stages IA/B and IC based upon rupture alone, IC other (cytologic positivity and/or surface involvement), and II, respectively. No benefit in DFS was accrued in stage IA/B from adjuvant treatment. Decision tree analysis defined 2 poor prognostic groups: those 55 years or older with stage IC based upon positive washings or surface involvement and any patient with stage II disease; in these, an apparent DFS benefit from irradiation was seen (relative risk (RR), 1.77; 95% confidence interval (CI), 0.74–4.24).

Conclusion Omission of adjuvant treatment can be considered in most early-stage OECs.