Years of life lost from metastatic prostate cancer according to household income

Abstract

Introduction: Years of life lost (YLL) from metastatic prostate cancer (mPCa) according to household income, relative to population controls, have not been quantified.

Methods: Within the Surveillance, Epidemiology, and End Results (SEER) database (2004-2021), mPCa patients aged 40-80 years were identified and stratified between low vs. high household income based on the median distribution. For each patient, an age- and sex-matched control was generated from Social Security Administration life tables using Monte Carlo simulation. YLL of low vs. high income mPCa patients were quantified relative to simulated controls, until the age of 80 years, using Kaplan-Meier methodology. Subsequently, multivariable competing risks regression (CRR) models were fitted.

Results: Overall, 37,094 mPCa patients were included. The median household income ranged from $75k to $80k/year, with 20,004 (53.9%) low vs. 17,090 (46.1%) high income mPCa patients. YLL values were 7.7 in low vs. 5.9 in high income mPCa patients (Δ: 1.8). In sensitivity analyses among metastatic substages, YLL values were as follows: 6.2 vs. 4.7 (Δ: 1.5) in M1a, 7.5 vs. 5.6 (Δ: 1.9) in M1b, 8.9 vs. 7.3 (Δ: 1.6) in M1c, in low vs. high income mPCa patients, respectively. In multivariable CRR models, household income independently predicted 1.1-fold higher cancer-specific mortality (CSM, multivariable hazard ratio [mHR] 1.14; p < 0.001). In sensitivity analyses stratified by metastatic substage, mHRs for CSM were as follows: 1.22 (p < 0.001) in M1a, 1.14 (p < 0.001) in M1b, 1.11 in M1c (p < 0.001).

Conclusion: Low household income is associated with less favorable overall survival and higher CSM in mPCa patients. In consequence, measures aimed at reducing or ideally eliminating these survival disadvantages should be implemented.

Keywords: Household income; Prostate cancer; SEER database; Survival; Years of life lost.