The impact of sex and age on distribution of metastases in patients with renal cell carcinoma

Background: Our objective was to investigate age and sex-related discrepancies on distribution of metastases in patients with metastatic renal cell carcinoma (RCC). Methods: Within the National Inpatient Sample database (2008–2015) we identified 9607 patients with metastatic RCC. Trend test and Chi-square test analyses were used to evaluate the relationship between age and site of metastases, according to sex. Results: Of 9607 patients with metastatic RCC, 6344 (65.9%) were men and 3263 (34.1%) were women. Thoracic, abdominal, bone and brain metastases were present in 51.1 vs. 52.8%, 42.6 vs. 44.3%, 29.9 vs. 29.2% and 8.6 vs. 8.8% of men vs. women, respectively. Increasing age was associated with decreasing rates of thoracic (from 55.5 to 48.5%) and brain (from 8.6 to 5.8%) metastases in men and with decreasing rates of abdominal (from 48.3 to 39.6%), bone (from 32.6 to 24.9%) and brain (from 8.8 to 5.4%) metastases in women. (all p < 0.05). Rates of concomitant metastatic sites also decreased with increasing age, from 57.1 to 50.8% in men and from 54.1 to 50.2% in women. Conclusions: Important age and sex-related differences exist in the distribution of RCC metastases. The distribution of metastases is marginally different between sexes. Specifically, more advanced age is associated with lower rates of thoracic and brain metastases in men and with lower rates of abdominal, bone and brain metastases in women. Age and sex should be take into consideration into the staging management strategy, as well as into the follow-up strategy of patients with metastatic RCC.