The effect of race/ethnicity on cancer-specific mortality after trimodal therapy

Trimodal therapy (TMT) is the most validated bladder-sparing treatment for organ-confined urothelial carcinoma of the urinary bladder (OC UCUB, namely cT2N0M0). However, it is unknown if barriers to the use of TMT or cancer-specific mortality (CSM) differences exist according to race/ethnicity. We addressed this knowledge gap.

Within the Surveillance, Epidemiology, and End Results database (2004-2020), we identified OC UCUB patients aged from 18 to 85 treated with radical cystectomy (RC) or TMT. Temporal trends described TMT versus RC use over time. Subsequently, in the subgroup of TMT-treated patients, survival analyses consisting of Kaplan-Meier plots and multivariable Cox regression (MCR) models addressed CSM according to race/ethnicity.

Among 19,501 assessable patients, 15,336 (79%) underwent RC versus 4165 TMT (21%). Overall, of all races/ethnicities, 16,245 (83.3%) were White Americans, 1215 (6.3%) Hispanics, 1160 (5.9%) African Americans, and 881 (4.5%) Asian/Pacific Islanders. Among TMT-treated patients, 3460 (83.1%) were White Americans, 298 (7.1%) African Americans, 218 (5.3%) Hispanics, and 189 (4.5%) Asian/Pacific Islanders. The lowest rate of TMT use relative to RC and TMT patients was recorded in Hispanics (17.9%). Over time, TMT use increased in White Americans (EAPC: + 4.5%, p = 0.001) and Asians/Pacific Islanders (EAPC: + 5.2%, p = 0.003), but not in others. Kaplan-Meier analyses showed median CSM of 49 months, 41 months, and 34 months and not reached in White Americans, Hispanics, African Americans, and Asian/Pacific Islanders, respectively (p = 0.02). In MCR models, two race/ethnicity subgroups independently predicted either worse (African Americans, HR: 1.20, p = 0.02) or better CSM (Asian/Pacific Islanders, HR: 0.75, p = 0.02).

Race/ethnicity affects both access to TMT (lower access in Hispanics) as well as survival after TMT (better in Asians/Pacific Islanders and worse in African Americans).