Health Rounds: Newer genetic tests underused in critically ill kids

(Health Rounds is published on Tuesdays and Thursdays. Think your friend or colleague should know about us? Forward this newsletter to them. They can also subscribe here.)

Jan 31 (Reuters) - Welcome to Health Rounds! Health Rounds has been running for almost a month now and it is time to ask you, the readers, for feedback: Are you interested in early advances that are still at the laboratory stage or studies that could possibly change the way medicine is practiced today? Write to me at

Meanwhile, today we highlight three potentially practice-changing studies, one of which found that if you’re a U.S. woman with recently diagnosed early-stage breast cancer who just turned 70, beware: you might be significantly less likely to be treated with medically indicated radiation than if you were still 69.

Rapid genetic testing underused in critically ill children

When the reason for a child’s critical illness is unclear, rapid genetic testing often helps identify the problem and point doctors to the right treatment – but it is currently underused, researchers say.

Rapid whole-genome sequencing (rWGS) is a relatively new alternative to older methods for determining someone’s entire genetic makeup. Results can be obtained in as few as two or three days.

At three major medical centers, doctors employed rWGS in 80 very sick patients under age 21 in the pediatric intensive care unit (ICU) whose illnesses had them mystified. In 65%, rWGS revealed genetic variants that had not previously been recognized in these children, Dr. Katherine Rodriguez of Rady Children’s Hospital in San Diego reported at the Society of Critical Care Medicine 2023 Critical Care Congress.

In 38% of those children, the findings prompted changes in medications or helped avoid unnecessary procedures.

rWGS is increasingly being used to diagnose genetic conditions in time to affect ICU management of newborns, but its use in pediatric ICUs is still rare, Rodriguez said in a statement.

“These findings suggest it can be beneficial and help alter the course of treatment... in critically ill children in whom a genetic cause is suspected or the cause of their illness is unclear,” she said.

Are breast cancer doctors biased against 70-year-olds?

U.S. women with high-risk early-stage breast cancer who would routinely receive radiation treatment at age 69 are nearly twice as likely to not get the treatment once they turn 70, a new study found.

“While we would expect recommendations for this treatment to decline gradually as expected lifespan shortens, there seems to be a steep cliff when a patient moves from their 60s to their 70s,” said Dr. Wesley Talcott of Northwell Health in New York, who led the study while at Yale School of Medicine.

“In breast oncology, physicians seem to anchor on a patient entering their 70s as a signal to de-escalate care, even in situations where evidence does not support this practice,” he said in a statement.

Researchers analyzed data on more than 530,000 women, ages 50 to 80, who underwent lumpectomy for early-stage breast cancer between 2004 and 2017 and who had clear medical reasons for radiotherapy regardless of age.

After accounting for other health and socioeconomic risk factors, age 70 at diagnosis was associated with 53% lower odds of having doctors recommend radiation after their surgery, compared with age 69 at diagnosis, they reported on Tuesday in the International Journal of Radiation Oncology Biology Physics.

The researchers did not have follow-up data that would demonstrate whether withholding radiation affected patient outcomes. Still, they said, the effects are likely to be “clinically meaningful.”

“Our study indicates that physicians should be mindful of how we factor age into treatment decisions and adopt a more nuanced approach, extending beyond defining patients as simply ‘young’ or ‘elderly,’” Talcott said.

Older implanted defibrillators still work years after MRI

People with older Implantable Cardioverter Defibrillators (ICDs) can undergo magnetic resonance imaging (MRI) without worrying the devices will not function properly years later, researchers say.

ICDs are placed in the heart to detect deadly rhythm abnormalities and deliver an electric shock to “reset” the heart and potentially save the patient’s life. Newer ICDs are made of magnet-safe materials, but more than a million people in the United States alone are walking around with older devices that were not specifically designed to withstand MRI.

Earlier evidence has shown that MRI does not disable older ICDs, but whether dysfunction develops slowly afterward has been unclear. Many facilities continue to turn these patients away.

At Johns Hopkins University in Baltimore, researchers studied 629 patients with older ICDs who underwent MRI at standard magnetic field settings between 2003 and 2015.

During a median follow-up of 2.2 years, the ICDs continued to function appropriately, with “no direct evidence of ICD failure to deliver therapy,” they reported on Monday in Annals of Internal Medicine.

“Shocks were delivered to and terminated more than 200 documented episodes of (life-threatening heart rhythms) in almost 100 patients,” they added.

Study leader Dr. Joshua Ra, who is now at the University of California, San Francisco, said after his team performed MRI exams in their first few patients with older ICDs, they decided that no special restrictions were needed on the equipment’s electromagnetic energy settings, beyond what they usually adhered to. (Reporting by Nancy Lapid; Editing by Bill Berkrot)