Health Rounds: New test detects deadly lung cancer earlier

(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 24 (Reuters) - Hello Health Rounds Readers! Today we look at early-stage research that suggests we may soon be able to detect a deadly form of lung cancer before it spreads and becomes incurable, while it might also be possible one day to halt the cascade of cardiac injuries that follows a heart attack. While those advances may take time to come to fruition for patients, results of a third study looking at transmission of ulcer-causing bacteria could be clinically useful today.

New test detects a stealthy lung cancer earlier

For the first time, a deadly form of lung cancer may be diagnosable while still curable, a new study looking at antibodies associated with the disease has found.

Small-cell lung cancer (SCLC) accounts for about 14% of U.S. lung cancer diagnoses and is the sixth leading cause of U.S. cancer deaths. Whereas CT scans are good at screening for other lung cancers, they are not useful for detecting SCLC before it spreads through the body. At the time of diagnosis, 70% of SCLC cases are metastatic, and the five-year survival rate is less than 6%.

Patients with SCLC are known to have antibodies that mistakenly attack their nerves. The authors of a new report in Science Translational Medicine have now identified five such “autoantibodies” that are present in particularly high levels in patients with SCLC and can be used to identify them at early stages.

In experiments using stored blood samples from three large groups of patients with and without SCLC, positive tests for the autoantibody panel were roughly 65% to 79% accurate for diagnosing the disease, and negative tests were 65% to 87% accurate at ruling it out, the researchers said.

Adding patients’ smoking history to the results of the blood tests makes the predictions even more accurate, they found.

Dr. Paul Lampe, whose team at the Fred Hutchinson Cancer Center in Seattle conducted the research, said they plan to continue testing the assay and then apply for regulatory approval. The goal, he said, is to perform the test along with standard annual CT lung cancer screening in heavy smokers and other high-risk individuals.

“We also found that some of these autoantibodies attack proteins (on the) surface of tumor cells,” study leader Kristin Lastwika told Reuters. “We are currently investigating these tumor-specific proteins as new targets for cancer therapies and early detection imaging.”

Gene editing prevents heart attack injury in mice

An experimental therapy may one day help prevent the damage to the heart that usually results from a heart attack, a study in mice suggests.

When arteries carrying blood to the heart are blocked during a heart attack, a stress enzyme called CaMKII-delta gets over-activated, initiating a cascade of harmful effects. By using a harmless virus to carry a gene-editing tool called CRISPR-Cas9 into heart cells after a heart attack, researchers were able to slightly modify the CaMKII-delta gene to prevent this over-activation and the resulting injury, they reported in Science.

Initially, the researchers tested the treatment in laboratory experiments on human heart cells that had been exposed to low levels of oxygen to mimic a heart attack.

“While untreated heart cells developed various markers of damage, CaMKII-delta-edited heart cells were protected,” said study leader Dr. Simon Lebek of the University of Texas Southwestern Medical Center in Dallas.

Next, his team administered the gene treatment to mice following a heart attack.

Treated mice showed almost normal heart function after a few weeks, while untreated animals were left with impaired heart function, scar formation, and heart cell death, Lebek said.

There is still much work ahead before this therapy can be tested in humans, and even if it proves useful, procedures to reopen coronary arteries will still be the primary treatment for heart attack, he said.

But because heart function is still often impaired after coronary arteries are reopened and stented, “our approach might be applied in conjunction with catheter interventions to improve cardiac function after a heart attack,” Lebek said.

Ulcer-causing bacteria can spread in families

When gastrointestinal problems involve Helicobacter pylori (H. pylori) bacteria, the patient’s household members should be screened for infection as well, a Chinese study has found.

Although usually asymptomatic, infections of the stomach or the first part of the small intestine with H. pylori are the most common causes of peptic ulcer disease. H. pylori can also cause gastritis, an irritation of the stomach lining and, on rare occasions, if untreated can lead to stomach cancer.

Researchers in China performed H. pylori tests on all the members of 10,735 families in 29 provinces. Among the 31,098 individuals in the study, roughly 43% of adults and 21% of children and adolescents were found to be infected.

Only 29% of families had no infections. The remaining 71% all had at least one infected member, including 20% in which all family members were infected, the researchers reported in Gut.

Exposure to infected family members is likely the major source of its spread, the researchers surmised.

While 14% of children and adolescents living with uninfected parents were themselves infected, that rate was 34% among children living with two infected parents.

H. pylori prevalence is particularly high in China.

According to the U.S. National Institute of Diabetes and Digestive and Kidney Diseases, H. pylori infections affect 30% to 40% of people in the United States. Most often, the infection is acquired in childhood.

The researchers said their findings suggest that when a patient is found to be infected with H. pylori, the entire family should be tested and all infected members should be treated. The infections are eradicated with antibiotics. (Reporting by Nancy Lapid; Editing by Bill Berkrot)