GUIDELINES FOR LUNG CANCER SCREENING

April 24, 2012 — The American Lung Association (ALA) is recommending low-dose computed tomography (CT) to screen certain populations for lung cancer.

The newly released interim guidance recommends screening only for individuals who meet specific criteria. They must be current or former smokers (having quit in the previous 15 years) who are 55 to 74 years of age with a smoking history of at least 30 pack-years (1 pack per day for 30 years, 2 packs per day for 15 years, etc.) and with no history of lung cancer.

This is similar to the recommendations issued late last year by the National Comprehensive Cancer Network (NCCN), which are based on the highest level of evidence (i.e., a randomized clinical trial).

Like the NCCN, the ALA has based its recommendations on recent research from the National Cancer Institute National Lung Cancer Screening Trial (NLST), which provided "provocative evidence" that screening with low-dose helical CT could reduce lung cancer mortality by more than 20%, compared with chest x-ray.

At this time, there is no evidence that other high-risk groups should be screened for lung cancer, the ALA guidance emphasizes. In addition, only low-dose CT scans are recommended for screening; chest x-rays are not. Smoking cessation should be continuously encouraged in individuals who chose to be screened; it remains the best method of reducing the risk for lung cancer.

The guidance was developed by the ALA Lung Cancer Screening Committee, which was chaired by Jonathan Samet, MD, MS, from the University of Southern California in Los Angeles. The goal was to review current scientific evidence on lung cancer screening and to provide guidance to physicians, their patients, and the public in their discussions about lung cancer screening.

"Our hope is that [this] will guide the public on this very important personal and public health issue," said Albert Rizzo, MD, board chair of the American Lung Association, in a statement. "We believe that the [guidance] and the educational materials that will stem from it will be invaluable to the tens of millions at risk for lung cancer."

Questions Remain

As previously reported by Medscape Medical News, the NLST is the first randomized controlled trial of lung cancer screening to show a significant mortality benefit. The study was stopped after 8 years, when the results clearly showed the benefit of CT screening.

However, despite the encouraging results, a number of questions about screening remain, and some experts have recommended caution before any type of screening program is launched.

At the 2011 American Association for Cancer Research (AACR) International Conference, John L. Field, PhD, BDS, FRCPath, noted that there are a number of unresolved issues with respect to CT screening for lung cancer.

"These issues include defining optimal risk populations, cost effectiveness, and harmonization of CT screening protocols; the whole area of work-up techniques is still an open question," noted Dr. Field, who is director of research at the Roy Castle Lung Cancer Research Programme, University of Liverpool Cancer Research Centre, United Kingdom. In addition, optimal surgical management, screening intervals, and screening rounds must be defined.

Christine Berg, MD, chief of the early detection research group at the division of cancer prevention, National Cancer Institute, and codirector of the NLST, agreed at that time that even though lung cancer screening holds much promise, "there is a lot of work to be done before it is rolled out into cancer screening programs around the world."

"The National Lung Screening Trial was designed to answer one question only: Does screening with low-dose helical CT lower lung-cancer-specific mortality?" she explained during the AACR session. "We designed the study to have the shortest time period, the fewest number of participants, the fewest number of screens, and the lowest cost to answer that question."

There are numerous questions that will have to be addressed in future research, she noted.

The ALA guidance provides a comprehensive review of the available evidence on the benefits and risks of lung cancer screening and highlights areas where more research is needed.

The committee acknowledges that screening is associated with benefits and risks, and that the NLST was not designed to address the advantages and safety of screening in the general population or other high-risk groups. There are no data, for example, on the optimal method and the effectiveness of low-dose CT screening in high-risk groups, such as younger people who already have 30 pack-years of smoking.

The evidence does not yet offer recommendations for people with chronic obstructive pulmonary disease (COPD), a key constituency for the ALA, the committee notes. There is also no evidence at this time that all current and former smokers or never smokers exposed to secondhand smoke should be screened with CT.

Additional Recommendations

To assist patients in making an informed choice about screening, the committee recommends that the ALA develop a toolkit that "will provide a comprehensive framework on the lung cancer screening process, outlining the potential benefits, risks, costs (emotional, physical, and economic) of lung cancer screening to assist people with lung disease, particularly COPD, in discussions with their pulmonologist or other knowledgeable physician regarding the advisability of low-dose CT screening in the context of the severity of their disease."

Because lung cancer screening is not currently covered by private insurers or Medicare, the committee addressed the ethics of facilities using low-cost or free screenings to recruit patients — in the absence of providing guidance about the risk and benefit and potential future costs. The committee recommends that the ALA "call upon all hospitals and screening centers to establish ethical policies for advertising and promoting lung cancer screening with low-dose CT."

In addition, hospitals and screening centers should use this opportunity to "fully educate the public about lung cancer, its risks and prevention, and the importance of careful and thoughtful discussions between patients and their physicians."

Finally, the committee recommends that the ALA strongly advocate that screening be linked to access to best-practice multidisciplinary teams, which can provide the optimal follow-up for the evaluation of nodules.