Racial and socioeconomic disparities in survival improvement of eight cancers

BACKGROUND: Many studies have characterized racial differences in cancer outcomes, demonstrating that black and Hispanic patients have lower cancer-specific survival compared to white patients. However, to our knowledge, a gap in the literature exists regarding racial, socioeconomic, age, and sex-related differences in survival improvement in cancer. METHODS: We perform a population-based cohort study of 1,875,281 patients with eight common cancer sites from the Surveillance, Epidemiology, and End Results (SEER) database. RESULTS: The longitudinal data demonstrates that while overall cancer-free survival has improved from 2004 to 2018, certain groups have seen lower rates of improvement. Black patients have the lowest cancer-specific survival (CSS) in breast, prostate, ovarian, colon, liver, lung, and pancreatic cancers. However, from 2009 to 2018, black patients have seen the greatest survival improvement in breast, ovarian, colorectal, liver, lung, and pancreatic cancer, though CSS for black patients still lags behind other groups. Strikingly, however, in breast and prostate cancer, black patient CSS from 2014 to 2018 remains lower than white patient CSS from 2004 to 2008 after controlling for income, age, and stage. CONCLUSIONS: While the racial disparity gap is closing in some forms of cancer, future research should focus on identifying factors causing disparate outcomes to help reduce cancer-related disparities.

Vikram Shaw, Baoyi Zhang, Mabel Tang, William Peng, Christopher Amos, Chao Cheng