Sex- and age-related differences in the distribution of bladder cancer metastases.

Abstract

Our objective was to investigate age- and sex-related differences in the distribution of metastases in patients with metastatic bladder cancer. Within the National Inpatient Sample database (2008-2015), we identified 7040 patients with metastatic bladder cancer. Trend test and Chi-square test analyses were used to evaluate the relationship between age and site of metastases, according to sex. Of 7040 patients with metastatic bladder cancer, 5226 (74.2%) were men and 1814 (25.8%) were women. Thoracic, abdominal, bone and brain metastases were present in 19.5 vs. 23.0%, 43.6 vs. 46.9%, 23.9 vs. 18.7% and 2.4 vs. 2.9% of men vs. women, respectively. Bone was the most common metastatic site in men (23.9%) vs. lung in women (22.4%). Increasing age was associated with decreasing rates of abdominal (from 44.9 to 40.2%) and brain (from 3.2 to 1.4%) metastases in men vs. decreasing rates of bone (from 21.0 to 13.3%) and brain (from 5.1 to 2.0%) metastases in women (all P<0.05). Finally, rates of metastases in multiple organs also decreased with age, in both men and women. The distribution of metastases in bladder cancer varies according to sex. Moreover, differences exist according to patient age and these differences are also sex-specific. In consequence, patient age and sex should be considered in the interpretation of imaging, especially when findings are indeterminate.