Racial Disparities Persist Across Cancer Incidence and Clinical Trial Outcomes

Two separate studies published in JAMA Network Open highlight ongoing racial disparities in cancer incidence trends and clinical trial outcomes in the United States, underscoring persistent gaps in both disease burden and research representation.

The first study, a cross-sectional analysis using data from the US Cancer Statistics Database spanning January 2003 to December 2022, found that early-onset cancer rates have declined among men while increasing among women, with notable differences by race. The analysis focused on non-Hispanic Black and White individuals aged 20 to 49 years. Among men, rates fell for Black men from 127.1 to 107.5 cases per 100,000 (average annual percentage change [AAPC] of −0.7) and for White men from 123.8 to 120.9 cases per 100,000 (AAPC of −0.1). Among women, early-onset cancer rates rose from 180.1 to 184.9 cases per 100,000 for Black women and from 196.6 to 222.4 cases per 100,000 for White women, with the increase reaching statistical significance only among White women (AAPC of 0.7).

The largest increases by cancer site and demographic included kidney cancer among Black men (AAPC of 1.8), colorectal cancer (CRC) among White men (AAPC of 2.3), uterine cancer among Black women (AAPC of 1.9), and kidney cancer among White women (AAPC of 2.5). Researchers noted that large increases in colorectal cancer rates in 2021 and 2022 are likely related to new recommendations to begin screening at age 45 years.

The study also tracked shifting racial incidence rate ratios (IRRs) comparing Black to White individuals over the study period. Prostate cancer IRRs rose from 2.40 in 2003 to 2.83 in 2022, while breast cancer IRRs declined from 1.03 to 0.94, indicating higher rates among White women. Lung cancer IRRs for men initially fell from 1.57 in 2003 to 1.05 in 2013 but rebounded to 1.58 by 2022, despite comparable cigarette smoking prevalence between Black and White populations. Early-onset CRC rates were higher among Black women but the racial difference narrowed over time, with the IRR falling from 1.38 in 2003 to 1.16 in 2022. The researchers concluded that addressing racial differences in early-onset cancers requires interventions targeting socioeconomic determinants of risk and equitable access to preventive care. The study was supported by the National Institutes of Health Intramural Research Program of the National Cancer Institute.

A separate cohort study examined racial representation and survival outcomes in advanced ovarian cancer clinical trials. Researchers conducted a pooled analysis of 1,903 patients with stage 3 or stage 4 epithelial ovarian cancer enrolled in four first-line randomized clinical trials — GOG-111, GOG-114, GOG-158, and GOG-172 — conducted between 1996 and 2006.

Among the 1,903 participants, 1,747 (91.80%) self-identified as White, 121 (6.36%) as Black, and 35 (1.84%) as Asian. After adjusting for clinical and demographic factors including age, cancer stage, tumor characteristics, and route of chemotherapy administration, Black patients had a higher risk of death compared with White patients. Asian patients had overall survival outcomes similar to White patients in adjusted analyses. Progression-free survival did not significantly differ among the racial groups, suggesting that the timing of cancer recurrence or progression was similar across groups even though overall survival outcomes differed.

The study's authors noted that the trials did not collect information on ethnicity, meaning Hispanic patients could not be separately accounted for, reflecting a broader limitation in consistent reporting of race and ethnicity in clinical trials. All participants had histologically confirmed advanced epithelial ovarian cancer, and surgical outcomes differed across the four trials, with GOG-111 enrolling patients with suboptimally resected disease and the remaining three trials enrolling those with optimally resected disease.