Gender-specific differences in bladder cancer: a retrospective analysis

Abstract

Background: A higher incidence of bladder cancer has been reported in men compared with women. Clinical gender differences have been observed but are less well described.

Objective: This retrospective analysis further examines clinical differences in the development and manifestation of bladder cancer between men and women.

Methods: Consecutive male and female patients with bladder cancer treated between 1969 and 1997 at a single center (University Hospital of Innsbruck, Innsbruck, Austria) were included in the study. Patient characteristics regarding age, tumor classification, localization, and recurrence were compared between male and female patients. Statistical analysis was conducted using the t test, the chi(2) test, and the Kaplan-Meier method, with the log-rank test for subgroup analysis.

Results: In the 1,269 patients (876 men, 393 women) who were examined, 1,744 tumors were found. The male-to-female bladder cancer incidence ratio was 2.2:1. Tumors were diagnosed at a significantly younger age in men than in women (mean age: 62 years vs 67 years, respectively; P < 0.001). No difference in the histology of tumors was observed between the sexes. Muscle-invasive tumors more frequently occurred in men than in women (39.8% vs 34.5%; P = NS). In men compared with women, primary tumors were more aggressive (grade 2, 36.6% vs 28.2%; P < 0.001) and tumor recurrences were more invasive (59.0% vs 57.8%; P = NS). Tumors were more often located in the urethra in men than in women (43 [3.4%] vs 9 [1.8%]; P = 0.034), the trigonum (246 [19.8%] vs 75 [14.9%]; P < 0.001), and the bladder dome or vault (128 [10.3%] vs 37 [7.4%]; P = 0.015). Generally, no difference in survival rate was observed between the sexes; only in the subgroup of muscle-invasive tumors (n = 455) did women have a worse overall survival rate than did men (P = 0.022).

Conclusions: Clinical gender differences in bladder cancer appear to have a higher incidence in men than in women. In this analysis, women were older at the age of detection, but had less-invasive and less-aggressive tumors than did men. However, women with muscle-invasive disease had a worse overall survival rate than did men in the same subset.