Lung Cancer Screening: Who Should Consider It

Lung cancer is the leading cause of cancer death in both men and women, yet many people don't realize that screening is available for those at high risk. Low-dose computed tomography (LDCT) screening can detect lung cancer at earlier, more treatable stages in people who meet specific criteria.

However, unlike some other cancer screenings, lung cancer screening isn't recommended for everyone. It's targeted specifically at people with significant smoking histories who are at highest risk.

Who Should Consider Lung Cancer Screening?

Current guidelines recommend annual lung cancer screening with low-dose CT for adults who meet all of the following criteria:

• Are between 50 and 80 years old
• Have a 20 pack-year smoking history or greater
• Currently smoke or have quit within the past 15 years
• Are in generally good health

Understanding Pack-Years

A pack-year is a way to measure how much someone has smoked over time. One pack-year equals smoking one pack of cigarettes per day for one year. To calculate your pack-years, multiply the number of packs smoked per day by the number of years smoked.

For example, if you smoked two packs a day for 15 years, that's 30 pack-years. If you smoked half a pack a day for 40 years, that's 20 pack-years. Both of these examples would meet the smoking history criterion for screening.

What Is Low-Dose CT Screening?

Low-dose CT (LDCT) uses special x-ray equipment to create detailed images of your lungs. The "low-dose" part means it uses much less radiation than a standard CT scan while still providing clear images that can detect small nodules or masses in the lungs.

What to Expect During Screening

The screening itself is quick and painless. You'll lie on a table that slides into the CT scanner. The scan takes only a few seconds, and you don't need any injections, medications, or contrast dye. You simply need to hold your breath for a few seconds while the images are captured.

The entire appointment typically takes about 15 to 30 minutes, though the actual scanning time is very brief. You can drive yourself to and from the appointment, and you can eat and take medications normally beforehand.

Why Early Detection Matters

Lung cancer often doesn't cause symptoms until it's advanced. By the time symptoms like persistent cough, shortness of breath, or chest pain appear, the cancer may have spread. This is why lung cancer has historically had poor survival rates.

However, when lung cancer is found early through screening before symptoms develop, it's much more treatable. The five-year survival rate for lung cancer detected at the earliest stage is about 60%, compared to just 7% when it's found after it has spread to distant parts of the body.

Large research studies have shown that annual low-dose CT screening in high-risk individuals reduces lung cancer deaths by about 20% compared to no screening or chest x-ray screening.

Understanding Your Results

After your screening, a radiologist will review the images and send a report to your healthcare provider. Results generally fall into several categories:

Negative Results

No nodules or masses were found. You should continue annual screening as long as you meet the criteria and are in good health.

Benign Findings

Something was seen, but it has characteristics that indicate it's not cancer. This might include calcified nodules or small lymph nodes. Continue annual screening.

Findings Requiring Follow-Up

A nodule was found that needs additional evaluation. This doesn't mean you have cancer. Many nodules are benign, caused by old infections, inflammation, or other non-cancerous conditions. Your doctor may recommend another CT scan in a few months to see if the nodule changes, or may suggest a PET scan or biopsy for further evaluation.

Suspected Cancer

The findings are very concerning for lung cancer. Your doctor will recommend additional tests, which might include a PET scan, biopsy, or referral to a lung specialist.

Potential Benefits of Screening

Beyond detecting lung cancer early, screening can provide other benefits:

• Finding other lung conditions early, such as emphysema or pulmonary fibrosis
• Detecting heart disease through incidental findings in the scan
• Providing a powerful motivation to quit smoking for those who still smoke
• Offering peace of mind for those at high risk

Understanding the Potential Harms

Like all medical tests, lung cancer screening has potential downsides to consider:

False Positives

This is the most common issue with lung cancer screening. Many people have small nodules in their lungs that aren't cancer. About one in four screening scans finds something that requires follow-up, though the vast majority of these findings turn out to be benign.

False positives can lead to anxiety and additional testing, including more CT scans, PET scans, or even lung biopsies, which carry their own small risks.

Overdiagnosis

Some slow-growing cancers detected through screening might never have caused health problems during a person's lifetime. However, once detected, they're typically treated, which means some people undergo treatment for cancers that wouldn't have harmed them.

Radiation Exposure

While LDCT uses much less radiation than standard CT scans, it still involves some radiation exposure. For people at high risk of lung cancer, the benefits of screening generally outweigh this small risk.

Incidental Findings

CT scans of the chest sometimes detect other abnormalities unrelated to lung cancer. Some of these findings require additional testing or follow-up, which can lead to more procedures and expense.

The Importance of Smoking Cessation

If you currently smoke, the single most important thing you can do for your health is to quit. While screening can detect lung cancer early, quitting smoking is the best way to reduce your risk of developing it in the first place.

Many lung cancer screening programs include smoking cessation support. Research shows that people who participate in screening are more motivated to quit smoking, particularly if nodules are found.

Quitting smoking has immediate and long-term benefits for your health, regardless of how long you've smoked. Your lung cancer risk begins to decrease as soon as you quit, though it takes years to approach the risk level of someone who never smoked.

Insurance Coverage

Medicare covers annual lung cancer screening with LDCT for people who meet the screening criteria. Most private insurance plans also cover lung cancer screening with no out-of-pocket costs when criteria are met, as required by the Affordable Care Act.

However, coverage may require a shared decision-making visit with your healthcare provider before the first screening. This visit ensures you understand the benefits and potential harms of screening.

Questions to Ask Your Healthcare Provider

If you think you might benefit from lung cancer screening, discuss these questions with your healthcare provider:

• Based on my smoking history, do I meet the criteria for lung cancer screening?
• Where can I get screened in this area?
• What happens if something is found on my scan?
• Will my insurance cover screening?
• How often should I be screened?
• What can I do to reduce my risk of lung cancer?
• Can you help me quit smoking?

When to Stop Screening

Guidelines recommend continuing annual screening until age 80, or until you develop a health problem that would make you unable to undergo surgery if lung cancer were found. If you quit smoking, you should continue screening for at least 15 years after quitting.