Low Socioeconomic Status May Account for Ethnic Survival Disparities in MM

The researchers found that socioeconomic status likely drives survival disparities between Hispanic patients and non-Hispanic whites (NHWs). They also found that, while both underserved populations, Hispanics and non-Hispanic blacks have different survival outcomes compared with NHWs.

Having a lower socioeconomic status (SES) drives disparities in survival outcomes for Hispanic patients with multiple myeloma, indicate new study findings.

Previous research has indicated that racial/ethnic minorities, including Hispanics and non-Hispanic blacks (NHBs), are disproportionately affected by low SES and are less likely to receive novel treatments. Research has also suggested that addressing this disparity could help improve outcomes. Data from the Surveillance, Epidemiology, and End Results (SEER)-Medicare database have showed that when treated similarly, NHB patients have significantly improved survival compared with non-Hispanic white (NHW) patients.

With similar insights lacking for Hispanics, researchers leveraged data from the same database, finding that SES likely drives survival disparities between Hispanic patients and NHWs. They also found that, while both underserved populations, Hispanics and NHBs have different survival outcomes compared with NHWs.

“Even though Hispanics and NHBs demonstrate similar and greater social and health challenges than NHWs at diagnosis, the survival disparities between these two underserved populations and NHWs are markedly different,” wrote the group. “When treated similarly, Hispanics and NHWs have comparable overall survival while NHBs have significantly longer survival than NHWs. In addition, among patients with low SES, NHBs have better survival than demographics-matched Hispanics. These findings indicate NHBs may harbor a more indolent disease subtype than other racial/ethnic groups.”

When determining differences in survival patterns between Hispanic patients and NHW patients, the researchers relied on SEER data from nearly 1600 Hispanics and over 20,000 NHWs, finding that Hispanics were more than twice as likely to have low SES (52.6% vs 23.1%).

Compared with demographics-matched NHWs, Hispanics had significantly worse median survival (30 vs 37 months) and 5-year survival rates (absolute difference, 3.6%). However, when they adjusted for SES, the differences were no longer significant (30 vs 32 months and absolute difference 2.2%, respectively). The group also found that when adjusting for demographic variables, being of Hispanic ethnicity was associated with increased risk of mortality but the association no longer remained when adjusting for SES, presentation, or treatment factors.

Stratification analyses showed that even if both Hispanics and NHWs were at a low SES, Hispanic patients still had an 18% increased risk of all-cause mortality compared with demographic-controlled NHWs.

“These results highlight the need to better understand factors beyond SES that impact MM survival disparities,” commented the researchers. “However, limited by the large number of missing values in disease-specific mortality, we were not able to assess MM-specific mortality to further examine whether comorbidities and treatments also impact MM-specific mortality. Of note, both comorbidities and treatment are important modifiable factors that may be affected by SES, providing us opportunities to eliminate these disparities.”

Reference

Buradagunta C, Garacci Z, D’Souza A, et al. Socioeconomic disadvantage contributes to ethnic disparities in multiple myeloma survival: a matched cohort study. Blood Cancer J. Published online May 25, 2022. doi:10.1038/s41408-022-00681-x