Kidney Cancer Research: Sex-Inclusive but Sex-Unspecific

Background: Preclinical and clinical research is largely inclusive of both the female and the male population, but the lack of specific separation of data according to patient sex prevents the detection of the impact of sex on cancer biology and response to medications and treatment. This study aimed to examine the consideration of sex as a biological variable in preclinical and clinical studies in kidney cancer. Methods: Preclinical and clinical studies pertaining to kidney cancer published in three leading urology journals over a two-year period were reviewed for the reporting of cells, animal or patient sex, and the inclusion of sex as a biological variable in both study design and data analysis. Results: 171 clinical studies and 5 preclinical studies were included. While the sex of the participants was disclosed in all but 10 of the 171 clinical studies reviewed, the patient populations were largely maledominated (male to female ratio > 1.5). Only 5 studies contained more female than male patients. Sexspecific reporting was performed in 3% of studies, and only 37% included sex as part of the statistical analysis. 26% of these identified a statistically significant difference in measured outcomes between male and female participants. Conclusion: Kidney cancer research is sex-inclusive, but the female patient population remains underrepresented. The consideration of sex in data analysis is low and could prevent the identification of key sex-specific optimization opportunities for the improved management of the disease.