Lung Cancer Screening Guideline: Frequently Asked Questions

What do the recommendations say?

The American Cancer Society lung cancer screening guidelines recommend yearly low dose CT (LDCT) for certain people at higher risk of lung cancer that meet the following conditions:

• Are aged 55 years to 74 years and are in fairly good health
• Are currently smokers or have quit within the past 15 years
• Have at least a 30-pack-year smoking history
• Receive smoking cessation counseling if they still smoke
• Have been involved in shared decision-making about the potential benefits, limitations, and harms associated with screening for lung cancer with LDCT
• Have access to a high-volume, high-quality lung cancer screening and treatment center

Why do these guidelines include a discussion about screening as part of a decision-making process?

The guidelines are consistent with a broad move toward shared decision-making in screening, which is designed to make sure that patients are fully informed about the benefits, limitations, and the potential adverse events of screening. The risks include false positive findings, which may involve follow-up testing that could be invasive, and some anxiety. Cost may also be an issue. For these reasons, it is important that adults eligible for screening know what to expect from testing.

Would someone who meets the criteria for being at higher risk but decides not to be screened still be following ACS guidelines?

Yes. Some people may be willing to accept the risks and costs associated with having a LDCT every year for its potential benefit of reducing their risk of dying from lung cancer. Some individuals may be willing to have further tests beyond the screening, even tests that have a rare but real risk of complications and death. Other people may place greater value on avoiding testing that carries a high risk of false-positive results and a small risk of complications. Of course, an individual who meets the criteria and chooses not to undergo screening may revisit the option for testing in the future. These are some reasons why being involved in informed/shared decision-making is important.

Do other groups have lung cancer screening recommendations?

Other organizations have issued lung cancer screening guidelines, and they are very similar to those from the American Cancer Society. They include the US Preventive Services Task Force, American College of Chest Physicians, the American Society of Clinical Oncology, the American Lung Association, the National Comprehensive Cancer Network, and the American Association for Thoracic Surgery.

Why doesn’t the American Cancer Society recommend screening for non-smokers?

Evidence from studies is not yet strong enough to show that LDCT scans are beneficial in healthy adults who never smoked, or current or former smokers with fewer pack-years of smoking. The current guidelines are based on evidence from studies involving smokers with specific smoking histories.

The evidence review found 8 randomized clinical trials looking at LDCT screening, all of which studied populations who smoked, who are known to be at significantly higher risk of lung cancer. The lowest minimum exposure in these trials was 15 pack-years, but more commonly was 20+ or 30+ pack-years. In 5 of those studies, the maximum allowable years since smoking cessation was 10 years, and in 2 studies it was 15 years. In developing this guideline, particular weight was given to the NLST results based on its larger study size. It studied men and women aged 55 years to 74 years in reasonably good health with 30 or more pack-years of smoking who were either current smokers or who quit within the past 15 years.

Why not screen younger smokers using LDCT?

At this time, researchers are still determining if screening should be offered to younger smokers who have a higher lifetime exposure to cigarette smoke. We know that for screening to be effective, the screened population should be at or above a certain level of risk. While younger, current smokers are at risk for developing lung cancer in the future, the incidence of lung cancer is lower in this younger age group. Screening in this group would likely pose more harm and less benefit than it would in the older population in which screening has been shown to be effective. Of greatest importance is that adults of every age stop smoking, which can reduce their risk of developing lung cancer in the future.

What are the downsides of screening?

While the direct harms of screening, most notably radiation exposure, are small, there are other harms associated with LDCT screening. They include issues such as anxiety associated with abnormal testing results, additional imaging tests and biopsy procedures associated with false-positive results, and the need to investigate incidental findings on LDCT that are outside of the lung field. There can also be serious harms. In rare instances, diagnostic evaluations (such as lung biopsy) in patients with and without lung cancer can lead to hospitalizations and death.

Can we know for sure how many lives screening will save?

No. Even though there is strong evidence supporting the value of screening for lung cancer with LDCT in the higher risk population who meet certain criteria, we don’t yet know how effective general screening for lung cancer with LDCT will be.

Will insurance pay for my scan?

We are not able to answer this question. At this time, Medicare covers LDCT screening once per year if a person meets certain criteria. Other insurance carriers cover the test, but some may not. The American Cancer Society has encouraged health plans to cover lung cancer screening in those who meet the criteria outlined in this recommendation. If you meet the screening criteria and decide screening may be a good option for you, it is best to check with your insurance carrier in advance.

Is this the final word on screening?

No. Additional scientific reports and clinical trials will continue to fill in the existing knowledge gaps. ACS guidelines are revised as new data become available.