TUESDAY, Sept. 17 (HealthDay News) -- A protein that can be detected using a noninvasive blood test might one day help aid in the early diagnosis of lung cancer, preliminary research suggests.

A study conducted by researchers in China found that people with lung cancer have high levels of the so-called "biomarker," isocitrate dehydrogenase (IDH1). The investigators pointed out that lung cancer is the leading cause of cancer deaths in both men and women in the United States and around the world, and diagnosing the disease sooner could help reduce its high mortality rate.

"This study is the first to report identification of IDH1 as a novel biomarker for the diagnosis of non-small cell lung cancers using a large number of clinical samples," Dr. Jie He, director of the laboratory of thoracic surgery at the Peking Union Medical College and Chinese Academy of Medical Sciences in Beijing, said in a news release from the American Association for Cancer Research.

"Lung cancer has a high mortality rate, mostly because of late diagnosis. With an increase in aging population, we are likely to see an increase in lung cancer incidence and a need for better biomarkers for early diagnosis. We have identified IDH1 as an effective plasma [blood] biomarker with high sensitivity and specificity in the diagnosis of [non-small cell lung cancer]," He continued, especially the type known as lung adenocarcinoma.

The study, published in the current issue of the journal Clinical Cancer Research, involved blood samples collected from 943 patients with non-small cell lung cancers and 479 people who did not have lung cancer (the "control" group). None of the patients was diagnosed or treated for cancer in the three years before the study began.

The study found that the median IDH1 levels in patients with lung adenocarcinoma were 2.7 times higher than the healthy participants. The levels of this protein were also 2.2 times higher in those with squamous cell carcinoma, compared to the control group.

He's team noted that IDH1 can be detected in the blood of lung cancer patients with 76 percent sensitivity and 77 percent specificity. That means 24 percent of the tests would miss lung cancer, and 23 percent would diagnose lung cancer when it wasn't there. The researchers noted that when combined with current markers used to diagnose lung cancer, the sensitivity increased to 86 percent.

"Based on the present data, IDH1 can be used to detect stage 1 lung cancer; however, it is also possible that IDH1 could be used to detect precancer but further studies are required to address that possibility," added He.

"Our research also suggests IDH1 may be involved in the development of lung cancer, and it may be a good target for the treatment of [non-small cell lung cancer]," said He. The research team is currently studying what causes the increase of IDH1 in lung cancer patients and what the findings mean for patients.

More information

The U.S. National Cancer Institute has more about lung cancer.