Clearing the Smoke on Lung Cancer Screenings

Lung cancer mortality reduced with CT scanning

(RxWiki News) Behind skin, prostate and breast cancers, lung cancer is one of the most frequently diagnosed - and most lethal - malignancies in this country, affecting the lives of 220,000 Americans and taking the lives of another 165,000 every year.  

Two medical groups have issued new lung cancer screening practice guidelines.

After reviewing randomized trials and other studies, a team of researchers has found that low-dose computerized tomography (LDCT) may benefit individuals at high risk of lung cancer.

"If you must smoke, talk to your doctor about lung cancer screenings."

Peter B. Bach, MD, of the Memorial Sloan-Kettering Cancer Center, led the review of eight randomized controlled trials and 13 cohort studies (analyzing risk factors in certain groups of people).

Three studies looked at the impact of LDCT on lifespan. One of these, the National Lung Screening Trial involving more than 50,000 people, showed that LDCT resulted in a 20 percent reduction in lung cancer deaths.

While encouraging, the study also found problems with the method, including a high percentage (90 percent) of detected nodules that required follow-up testing but turned out to be non-cancerous (false-positives).

Fred R. Hirsch, MD, PhD, professor of medicine and pathology at the University of Colorado Cancer Center, told dailyRx that better systems are needed to analyze the nodules that the screening detects.

"The technology for imaging techniques has over the years been further developed, and some screening studies for lung cancer are today applying more advanced CT technologies, i.e., volumetric assessments of the nodules," Dr. Hirsch said.

He added, "Furthermore, studies are ongoing to search for biomarkers, which can eventually be used as adjunct to the scan in order to better distinguish benign from malignant nodules."

Study authors note that "uncertainty exists about the potential harms of screening and the generalizability of results."

The American College of Chest Physicians and the American Society of Clinical Oncology clinical have used these findings as the basis for practice guidelines:

Recommendation 1: Annual LDCT should be offered to individuals aged 55-74 who have smoked a pack a day for 30 years (pack-years) or have quit within 15 years.

Recommendation 2: Such screening is not advised for people who have smoked for fewer than 30 pack-years, are younger than 55 or older than 74, quit smoking 15+ years ago or have other serious health issues.

According to Dr. Hirsch, "Studies are also ongoing to see if we can better identify the most optimal risk group. In the meantime, it is reasonable for the relevant high risk group described in the NLST study to consult with their doctors about the opportunity for spiral CT screening," said Dr. Hirsch, who is also Associate Director for International Programs at the University of Colorado.

This review was published May 20, 2012 in the Journal of the American Medical Association.

Reviewed by: 
Review Date: 
May 31, 2012