Health Rounds: Genetic testing improves treatment, survival for Black breast cancer patients

By Nancy Lapid

March 31 (Reuters) - Hello Health Rounds readers! Racial inequity in healthcare has been a common theme in Health Rounds, and today we feature a study that proposes a fix for one such disparity. We also report on a study that found certain drugs often taken for life after a heart attack may be safely discontinued, and another that discovered relief from long COVID fatigue via a common antidepressant.

Gene tests cut racial disparities in breast cancer survival

Advanced genetic testing could help erase significant disparities in breast cancer survival rates between white and Black patients, new research has found.

Currently, Black women in the U.S. have a 40% higher breast cancer mortality rate than white women, despite a 5% lower incidence of the disease.

Applying genetic testing to early breast cancer tumor samples collected from more than a thousand women, researchers found Black women had more high-risk tumors that are often missed by standard testing of clinical biomarkers, such as estrogen receptor status. That leads to under-treatment, which is likely to result in worse outcomes.

When tumors were analyzed by commercially available gene-profiling tools and patients had received appropriate care, Black women had the same “excellent” outcomes three years later as white women, according to a report of the study in npj Breast Cancer.

Tumor gene expression profiling was done using the MammaPrint and BluePrint tests from Agendia AGDX.O, which classify early-stage tumors as being at Ultra Low, Low, High 1, or High 2 risk for spreading throughout the body over the next 10 years. The results help to determine whether chemotherapy is necessary.

Three-year recurrence-free survival was driven by genomic subtype, not by race, the researchers found.

Black females with low-risk tumors based on MammaPrint and BluePrint had “excellent 10-year outcomes, with a 97.7% recurrence-free survival rate, the same outcome as white females,” the researchers reported.

Patients with high-risk tumors were five to 10 times more likely to develop distant metastases than those with low-risk tumors, regardless of race.

Roughly half of patients initially characterized as low-risk turned out to have more aggressive tumors based on genomic profiling, the researchers also found.

The data suggest “tumor genomic testing for all patients may help guide treatment decisions to ultimately reduce racial survival disparities among Black females with breast cancer,” said study coauthor Dr. Andrea Menicucci of Agendia.

Heart attack survivors may not need lifelong beta-blockers

Stable, relatively low-risk heart attack survivors can stop taking commonly prescribed drugs from the class known as beta-blockers after one year, rather than continuing it for life, according to a clinical trial from South Korea.

Researchers enrolled 2,540 patients who had recovered from a heart attack and had been prescribed beta-blockers such as metoprolol, sold under the brand name Lopressor, and atenolol.

Those who stopped taking the medicine after at least 12 months had similar odds of death, additional heart attacks, or hospitalization for heart failure as those who continued to take them, researchers reported at the American College of Cardiology scientific meeting in New Orleans.

At a median of 3.5 years, one or more of those serious adverse events had occurred in 7.2% of those who discontinued beta-blockers and 9% of those who continued them, according to study details also published in The New England Journal of Medicine.

Beta-blockers, which lower heart rate and blood pressure, have long been a mainstay of treatment to reduce the likelihood of subsequent cardiac events following a heart attack.

However, many studies confirming their benefits were conducted decades ago, before modern procedures and medications were available.

“In practice, for stable patients who are several years out from a heart attack, discontinuation can be considered through shared decision-making and with monitoring of blood pressure and heart rate,” study leader Dr. Joo-Yong Hahn of Samsung Medical Center in Seoul said in a statement.

“For patients with beta-blocker-related side effects —fatigue, dizziness, bradycardia, hypotension — the case for discontinuation is even stronger.”

Because all patients were enrolled in South Korea and relatively few women participated, the results might not be broadly applicable, the researchers noted.

Common antidepressant eases long COVID fatigue

The widely used, inexpensive antidepressant fluvoxamine significantly improved fatigue and quality of life among adults with long COVID in a clinical trial, researchers reported.

The trial enrolled 399 adults in Brazil with fatigue lasting at least 90 days after a confirmed SARS‑CoV‑2 infection. Participants were randomly assigned to receive fluvoxamine, the common diabetes drug metformin, or placebo for 60 days.

Fluvoxamine reduced fatigue more than placebo, with a 99% probability the drug outperformed the placebo, according to the report published in Annals of Internal Medicine.

“Fluvoxamine showed consistent and meaningful benefits, and because it's already widely used and well understood, it has clear potential for clinical use,” study leader Edward Mills of McMaster University in Hamilton, Ontario said in a statement.

Metformin has been shown to reduce the risk of developing long COVID when taken during the acute phase of infection, but it did not help people in this study with fatigue symptoms of established long COVID.

“This trial gives clinicians their first strong evidence for a medication that helps reduce long COVID fatigue,” study coauthor Jamie Forrest of the University of British Columbia said in a statement.

Professor Christiaan Vinkers of Amsterdam University Medical Centre, who was not involved in the study, said the findings should be interpreted cautiously because patients provided subjective reports on their symptoms and the study focused on fatigue and did not assess other long COVID features.

“The results are promising, but replication is essential, ideally in broader patient groups and with outcomes that capture the full spectrum of long COVID,” Vinkers said.