Worse survival seen for Black, Hispanic women with early stage breast cancer

Key takeaways:

• Young Black and Hispanic women had worse overall breast cancer survival vs. white women.
• Black women with hormone receptor positive tumors or BMI 25-30 kg/m² had worse recurrence-free survival vs. white women.

Black and Hispanic women with early stage breast cancer in certain subgroups had worse survival rates compared with women of other races and ethnicities, according to results of a cohort study published in JAMA Network Open.

“Age has been associated with survival in patients with [breast cancer]. Both younger and older age have been associated with differences in treatments and adherence as well as worse mortality,” Marla Lipsyc-Sharf, MD, a medical oncologist and clinician investigator in the department of medical oncology at the University of California Los Angeles, and colleagues wrote. “BMI has also been shown to be associated with [breast cancer] survival, although the role of BMI in racial and ethnic survival disparities, particularly among groups that are underreported and underrepresented in clinical trials, such as Hispanic patients, merits additional study.”

Lipsyc-Sharf and colleagues conducted a cohort study with 9,479 women (median age, 52 years) who were participants enrolled between 1997 and 2010 in four randomized adjuvant chemotherapy trials. The median follow-up was 9.8 years. Researchers compared survival rates for non-Hispanic Black and Hispanic women with non-Hispanic white women within subgroups of tumor subtype, age and BMI.

Overall, 4.4% of participants were Hispanic, 8.8% were non-Hispanic Black, 3% were of another race or ethnicity, and 79.5% were non-Hispanic white.

Of all participants with hormone receptor positive/ERBB2 tumors, non-Hispanic Black women had worse recurrence-free survival compared with non-Hispanic white women (HR = 1.49; 95% CI, 1.04-2.12; 88.5% vs. 93.2%). However, differences in recurrence-free survival were not significant for any tumor subtype when utilizing the global test for association of race and ethnicity.

Both race and ethnicity were linked to overall breast cancer survival for participants aged younger than 50 years (P= .008). Specifically, young non-Hispanic Black (HR = 1.34; 95% CI, 1.04-1.71; 86.6% vs. 92%) and young Hispanic (HR = 1.62; 95% CI, 1.16-2.29; 86.2% vs. 92%) women had worse overall breast cancer survival compared with young non-Hispanic white women.

Race and ethnicity were also linked to recurrence-free survival for women with BMI from 25 kg/m² to 30 kg/m². Of these participants, non-Hispanic Black women had worse recurrence-free survival compared with non-Hispanic white women (HR = 1.81; 95% CI, 1.23-2.68; 83.2% vs. 87.3%).

“These data suggest that, in addition to addressing the social and structural factors that contribute to racial and ethnic disparities overall, it may be necessary to identify and address subgroup-specific mechanisms underlying the observed associations,” the researchers wrote. “It is critical to evaluate specific contributors to racial and ethnic disparities in survival as these may inform future interventions to improve these disparities.”