Black patients with hormone receptor positive, HER2 negative metastatic breast cancer experienced shorter survival and were less likely to receive standard first-line targeted therapy compared with white patients, according to an analysis of 2,384 people in a large U.S. clinico-genomic database from 2017 to 2022 published recently in NPJ Breast Cancer.
These findings highlight ongoing racial disparities in access to care and outcomes and point to unmet medical needs that directly affect how long patients live. This study included 303 Black patients and 2,081 white patients.
Black patients were diagnosed with metastatic disease at a younger median age (59 years vs 65 years) and were more often premenopausal (29% vs 21%). They were also more likely to have grade 3 tumors (32% vs 25%), lung metastases (37% vs 30%) and brain metastases (19% vs 14%). White patients more often had bone-only metastases (19% vs 14%). Socioeconomic differences were also evident, with 25% of Black patients in the lowest socioeconomic category compared with 9.4% of White patients.
Genomic testing showed that PIK3CA mutations were less common in Black patients (34% vs 42%). Rates of AKT1, PTEN, ESR1 and BRCA1/2 alterations were similar. Most patients underwent next-generation sequencing after starting first-line treatment. Even though the PIK3CA mutation rate was lower in Black patients, more than one-third still had this alteration, reinforcing the importance of biomarker testing for all patients to guide targeted therapy.
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Treatment patterns differed substantially. While about 90% of patients in both groups received first-line therapy, Black patients were less likely to receive CDK4/6 inhibitors (53% vs 66%) and more likely to receive chemotherapy (27% vs 17%). After adjusting for age, socioeconomic status, insurance and tumor features, Black patients had 38% lower odds of receiving first-line CDK4/6 inhibitors. Importantly, patients treated with CDK4/6 inhibitors in the first line had longer median overall survival (42.7 months vs 32.5 months) regardless of race.
“The lower prevalence of PIK3CA mutations, reduced utilization of CDK4/6 inhibitors, and shorter survival in Black patients underscore the need for new strategies to ensure equitable access to effective treatments for all patients,” explained this study’s authors.
Median overall survival was 34.1 months for Black patients compared with 42.1 months for White patients. Black patients also had shorter progression-free survival (8.5 vs 11.2 months) and shorter first-line treatment duration (6.3 vs 9.1 months). However, among those who did receive first-line CDK4/6 inhibitors, survival differences by race were no longer statistically significant.
For patients, these findings mean that access to recommended targeted therapies can make a measurable difference in how long they live. The results underscore the need for equitable biomarker testing, timely treatment and consistent use of effective first-line therapies to help close survival gaps in metastatic breast cancer.
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