Demographic Factors Associated With Non-Guideline-Based Treatment of Kidney Cancer in the United States.

Importance: Significant demographic disparities have been found to exist in the delivery of health care. Demographic factors associated with clinical decision-making in kidney cancer have not been thoroughly studied. Objective: To determine whether demographic factors, including sex and race/ethnicity, are associated with receipt of non-guideline-based treatment for kidney cancer. Design, Setting, and Participants: This retrospective cohort study was conducted using data from the National Cancer Database for the years 2010 through 2017. Included patients were individuals aged 30 to 70 years with localized (ie, cT1-2, N0, M0) kidney cancer and no major medical comorbidities (ie, Charlson-Deyo Comorbidity Index score of 0 or 1) treated at Commission on Cancer-accredited health care institutions in the United States. Data were analyzed from November 2020 through March 2021. Exposures: Demographic factors, including sex, race/ethnicity, and insurance status. Main Outcomes and Measures: Receipt of non-guideline-based treatment (undertreatment or overtreatment) for kidney cancer, as defined by accepted clinical guidelines, was determined. Results: Among 158 445 patients treated for localized kidney cancer, 99 563 (62.8%) were men, 120 001 individuals (75.7%) were White, and 91 218 individuals (57.6%) had private insurance. The median (interquartile range) age was 58 (50-64) years. Of the study population, 48 544 individuals (30.6%) received non-guideline-based treatment. Female sex was associated with lower adjusted odds of undertreatment (odds ratio [OR], 0.82; 95% CI, 0.77-0.88; P < .001) and higher adjusted odds of overtreatment (OR, 1.27; 95% CI, 1.24-1.30; P < .001) compared with male sex. Compared with White patients, Black and Hispanic patients had higher adjusted odds of undertreatment (Black patients: OR, 1.42; 95% CI, 1.29-1.55; P < .001; Hispanic patients: OR, 1.20; 95% CI, 1.06-1.36; P = .004) and overtreatment (Black patients: OR, 1.09; 95% CI, 1.05-1.13; P < .001; Hispanic patients: OR, 1.06; 95% CI, 1.01-1.11, P = .01). Individuals who were uninsured, compared with those who had insurance, had statistically significantly higher adjusted odds of undertreatment (OR, 2.63; 95% CI, 2.29-3.01; P < .001) and lower adjusted odds of overtreatment (OR, 0.72; 95% CI, 0.67-0.77; P < .001). Conclusions and Relevance: This study found that there were significant disparities in treatment decision-making for patients with kidney cancer, with increased rates of non-guideline-based treatment for women and Black and Hispanic patients. These findings suggest that further research into the mechanisms underlying these disparities is warranted and that clinical and policy decision-making should take these disparities into account.