Association of Age with Non–muscle-invasive Bladder Cancer: Unearthing a Biological Basis for Epidemiological Disparities?

In patients with non–muscle-invasive bladder cancer, advanced age is associated with inferior oncological outcomes (recurrence, progression, and bladder cancer–specific mortality). These results reflect age-related differences in innate tumour biology. Age disparity in patients with non–muscle-invasive bladder cancer (NMIBC) exists. Whether this is due to differences in adequate cancer care or tumour biology is unclear. To investigate age disparities in NMIBC using the Surveillance, Epidemiology, and End Results (SEER)-Medicare and UROMOL datasets. The SEER-Medicare data were used to identify patients with clinical stage Ta, Tis, and T1 NMIBC between 2005 and 2017 (n = 32 225). Using the UROMOL cohort (n = 834), age disparities across transcriptomic, genomic, and spatial proteomic domains were assessed. For the SEER-Medicare data, multivariable competing-risk regression was used to examine the association between age and recurrence, progression, and bladder cancer–specific mortality (BCSM). For the UROMOL cohort, multivariable general linear model and multinomial logistic regression were performed to evaluate the association between age and tumour biology. An analysis of the SEER-Medicare cohort revealed 5-yr recurrence rates of 55.2%, 57.4%, and 58.9%; 5-yr progression rates of 25.6%, 29.2%, and 36.9%; and 5-yr BCSM rates of 3.9%, 5.8%, and 11.8% in patients aged 66–70, 71–80, and ≥81 yr, respectively. After multivariable adjustment, age ≥81 yr was associated with a higher risk of recurrence (hazard ratio [HR] 1.07, 95% confidence interval [CI] 1.03–1.12; p = 0.001), progression (HR 1.32, p