Do the number of risk factors influence the outcome of patients with endometrial cancer?

Purpose: Although 8 years have passed since the FIGO mandated surgical staging of corpus cancer, limited data have been published to assess the impact of irradiation (RT) on patients so treated. Despite the fact that retrospective reviews have documented pelvic failure rates ranging from 15-20% in patients with high risk uterine-confined disease who have received no or 'inadequate' RT, the role of RT has been questioned. Kadar et al (Ob. Gyn. 80: 655-659, 1992) suggest that the number of tumor related factors is the most important predictor of death and that RT did not affect the site of recurrence. We sought to corroborate these findings by constructing a large data base of women with corpus cancers managed with initial surgery followed by adjuvant irradiation. Methods and Materials: Between 1983 and 1993, 394 patients received adjuvant postoperative RT from one of three academic radiation practices. RT consisted of vaginal(V) brachytherapy alone in 28 pts, pelvic(P) RT in 169 pts, P +V in 167 pts, pelvic +paraaortic (P+P)RT in 13 pts and whole abdominal (WA) RT in 17 pts. Lymph nodes(LN) were evaluated in 213 (54%). The median number of pelvic and paraaortic LN in the pathology specimen were 6 and 4, respectively. Median followup until death was 63 months. Results: 5 year disease-free survival (DFS) rate and pelvic control rates were 77% and 91%, respectively. Risk factors (defined by Kadar) refer to cervical stroma involvement, myometrial invasion >(1(3)), grade 3, and capillary space invasion (CSI) for patients with PSI/II excluding unfavorable histologies. Multivariate analysis revealed that age, histology, and pathologic stage were independent prognostic indicators for disease free survival. The number of factors was not significantly associated with inferior outcomes as suggested by Kadar et al, who reported 5-year survival rates of 66% and 17% for patients with 2 and 3 or 4 risk factors, respectively. Conclusion: The excellent pelvic control and disease-free survival of patients with uterine-confined disease in this series suggest that adjuvant RT should continue for patients with high risk disease. This analysis of a large group of postoperatively treated patients will provide a basis for determining alternative treatment strategies for patients who have an increased risk of disease recurrence despite RT