The Effect of Nulliparity on Survival in Endometrial Cancer at Different Ages

Abstract

Objective. Nulliparity is a major independent risk factor for endometrial cancer in Japan. We examined the effect of nulliparity on survival in endometrial cancer at different ages.Methods. A retrospective study of 328 Japanese women with endometrial cancer was performed. The subjects were divided into two groups: a younger age group (women < 50 years) and an older age group (women ≥ 50 years). Parity was analyzed for its influence on survival.Results. No effect of nulliparity was observed on survival in the younger group. In the older women, nulliparity did not affect survival in 189 subjects with surgical stage I and II tumors (P < 0.27). In contrast, the cumulative 10-year survival rates associated with nulliparity, a parity of 1 or 2, and a parity of 3 or more were 7.7, 48.0, and 56.2% in 54 subjects with surgical stage III and IV tumors, respectively (P < 0.03). In these 54 subjects, the cumulative 10-year survival rates associated with < 6-month and > 7-month delays in diagnosis were 57.1 and 16.6%, respectively (P < 0.02). The prognostic impact of parity disappeared after adjustment for delay in diagnosis. Multivariate analysis including histopathological variables, parity, and delay in diagnosis showed no independent prognostic variable in the older subjects with surgical stage III and IV tumors.Conclusions. The negative effect of nulliparity on survival was observed in the older subjects with advanced-surgical-stage tumors. Delay in diagnosis contributed to the prognostic impact of nulliparity.