Evaluation of mild cognitive impairment and dementia in patients with metastatic renal cell carcinoma

Background: Dementia and cancer are both more common in adults as they age. As new cancer treatments become more popular, it is important to consider how these treatments might affect older patients. This study evaluates metastatic renal cell carcinoma (mRCC) as a risk factor for older adults developing mild cognitive impairment or dementia (MCI/D) and the impact of mRCC-directed therapies on the development of MCI/D. Methods: We identified patients diagnosed with mRCC in a Surveillance, Epidemiology, and End Results (SEER)-Medicare dataset from 2007 to 2015 and matched them to non-cancer controls. Exclusion criteria included age < 65 years at mRCC diagnosis and diagnosis of MCI/D within the year preceding mRCC diagnosis. The main outcome was time to incident MCI/D within one year of mRCC diagnosis for cases or cohort entry for non-cancer controls. Cox proportional hazards models were used to measure associations between mRCC and incident MCI/D as well as associations of oral anticancer agent (OAA) use with MCI/D development within the mRCC group. Results: Patients with mRCC (n = 2533) were matched to non-cancer controls (n = 7027). mRCC (hazard ratio [HR] 8.52, p < .001), being older (HR 1.05 per 1-year age increase, p < .001), and identifying as Black (HR 1.92, p = .047) were predictive of developing MCI/D. In addition, neither those initiating treatment with OAAs nor those who underwent nephrectomy were more likely to develop MCI/D. Conclusions: Patients with mRCC were more likely to develop MCI/D than those without mRCC. The medical and surgical therapies evaluated were not associated with increased incidence of MCI/D. The increased incidence of MCI/D in older adults with mRCC may be the result of the pathology itself or risk factors common to the two disease processes.