Black Women More Apt to Develop Distant Metastases After Breast Cancer Diagnosis

By Megan Brooks

June 08, 2021

NEW YORK (Reuters Health) - Black women are more likely than white women to develop distant metastases after being diagnosed with breast cancer, independent of age and stage of disease at diagnosis, a U.S. study suggests.

"Despite having a lower incidence rate of breast cancer when compared to white women, Black women have the highest breast-cancer death rate of all racial and ethnic groups. Distant metastases are considered the leading cause of death in breast cancer," Dr. Julia Blanter of the Icahn School of Medicine at Mount Sinai, in New York City, told Reuters Health by email.

"This study opens the door for a lot of future projects. Namely, finding the source of the continued existing disparity," said Dr. Blanter, who reported her research at the American Society of Clinical Oncology (ASCO) virtual annual meeting.

Dr. Blanter and colleagues did a follow-up study of 441 women (340 white and 101 Black) with breast cancer in the Mount Sinai Health System (MSHS) to determine differences in distant metastases among Black versus white women.

Median follow-up time was significantly longer for white women than for Black women (3.12 years vs. 2.51 years; P=0.017).

But Dr. Blanter noted that they couldn't account for those women who may have transitioned to care outside of the MSHS and may be following up at a different institution.

"I do think it would be beneficial to look at this more closely and see if there are true differences in follow-up time and if they are contributing to the poorer outcomes," she told Reuters Health.

Distant metastases after diagnosis developed in seven Black women versus only four white women (6.9% vs. 1.2%, P=0.004).

In multivariate analysis adjusting for age, race and stage at diagnosis, Black women were nearly six times more likely to have distant metastasis (odds ratio, 5.8; 95% confidence interval, 1.3 to 25.2), "further suggesting that racial disparities still exist in the development of distant metastases, independent from a late-stage diagnosis, Dr. Blanter said.

"There are several factors contributing to differences in outcomes between Black and white women with breast cancer. Although some of the disparity can be answered via pathophysiologic differences, some of it cannot be. We should be looking at other causes of the existing disparities in breast cancer and how to remedy them," she added.

SOURCE: American Society of Clinical Oncology annual meeting, held June 4-8, 2021.