USPSTF broadens lung-cancer screening eligibility

Two numbers moved

In March 2021 the US Preventive Services Task Force rewrote who should be offered a yearly low-dose CT scan of the chest to look for lung cancer.

The old 2013 rule covered adults aged 55 to 80 with at least a 30 pack-year smoking history. The new rule covers adults aged 50 to 80 with at least a 20 pack-year history. Both versions require that the person still smokes or quit within the past 15 years. The recommendation carries a Grade B.

A pack-year is one pack a day for one year. Twenty cigarettes a day for ten years is 10 pack-years; forty a day for ten years is 20.

Screening should stop, the Task Force says, once someone has not smoked for 15 years, or once a health problem meaningfully limits how long they are likely to live or their ability or willingness to have lung surgery aimed at cure.

Who the change reached

Lowering the two thresholds did not just add a few people at the edges. The Task Force's modeling put the increase in the eligible population at 87% overall.

The increase was not even. It was 78% among non-Hispanic White adults, 107% among non-Hispanic Black adults, and 112% among Hispanic adults. It was 80% among men and 96% among women.

The reason is arithmetic, not policy. Black and Hispanic adults who smoke, and women who smoke, tend to accumulate fewer pack-years than White men who smoke. A 30 pack-year bar therefore left more of them out even when their lung cancer risk was high. The Task Force cites a study in which 32% of Black people who smoked and later developed lung cancer would have qualified under the 2013 rule, against 56% of White people.

The evidence underneath

Seven randomized trials of low-dose CT were reviewed. Only two were large enough to detect a difference in lung cancer deaths.

The National Lung Screening Trial enrolled 53,454 people aged 55 to 74 with at least 30 pack-years, and screened them yearly for three years. It reported a 20% relative drop in lung cancer deaths. A later analysis with longer follow-up put it at 16%.

The Dutch-Belgian NELSON trial enrolled 15,792 people and screened at widening intervals. At ten years there were 181 lung cancer deaths in the screened group and 242 in the control group.

Modeling by the CISNET network suggested yearly screening does more good than every-other-year screening, which is why the recommendation says annual. Chest x-rays, sputum tests, and blood biomarkers were all reviewed and none is recommended.

The harms, stated plainly

The Task Force lists them: false positives leading to more tests and procedures, overdiagnosis, radiation, incidental findings, and anxiety.

The numbers are not small. In the NLST, 26.3% of baseline scans were false positives. NELSON reported 19.8% at baseline. A Veterans Health Administration program found 28.9%. Those trials predate Lung-RADS, the current system for classifying nodules; applying Lung-RADS retrospectively to NLST would have cut the baseline false-positive rate to 12.8%, at the cost of some missed cancers.

Most false positives are settled with repeat imaging rather than a needle. Across studies, between 0.09% and 0.56% of everyone screened had a needle biopsy for something that turned out not to be cancer. Our page on the benefits and harms of screening explains why both sides of that ledger belong in the decision.

Why the stakes are this high

American Cancer Society projections carried by SEER give 229,410 new US lung and bronchus cancer diagnoses in 2026 and 124,990 deaths — one in five of all cancer deaths. Five-year relative survival across all stages, for cases diagnosed in 2016 through 2022, is 29.5%.

Stage is why screening is even worth the harms. Localized disease carries 65.5% five-year relative survival. Regional carries 38.2%. Distant carries 10.5%. And 51% of lung cancers are already distant when found, against 24% localized.

These are group figures from past years. They do not describe any one person, and they lag behind current treatment.

Getting screened is the harder half

The Task Force notes that uptake is poor. In one study across ten states, 14.4% of people eligible under the 2013 rule had been screened in the previous year.

Screening is meant to start with a shared decision — a conversation about benefits, limits, and harms — and referral to a center experienced in lung screening. Anyone who still smokes should also be offered help to stop. Our guide to lung cancer screening covers what the scan involves and what a nodule result means.

When to get checked

Ask about a screening scan if all of these are true:

• You are 50 to 80 years old
• You have smoked the equivalent of a pack a day for 20 years or more
• You still smoke, or you quit within the last 15 years

Screening is for people without symptoms. Symptoms need a different conversation, and sooner. NCI lists these as reasons to check with a doctor:

• Chest discomfort or pain
• A cough that does not go away, or gets worse over time
• Trouble breathing, or wheezing
• Blood in sputum, the mucus coughed up from the lungs
• Hoarseness, or trouble swallowing
• Loss of appetite, or weight loss for no known reason
• Fatigue, or swelling in the face or the veins of the neck

Our page on quitting smoking covers the support that works.

What this does and doesn't change

• A Grade B recommendation triggers no-cost-sharing rules for most private plans. Medicare coverage is decided separately by CMS on its own schedule.
• Eligibility is a starting point for a conversation, not an instruction. The Task Force says clinicians should individualize the decision.
• Screening lowers the chance of dying from lung cancer in a high-risk group. It does not remove it, and it does not make smoking safe.
• These are the 2021 criteria. Check the Task Force site for the current version before acting on them.

Sources

• US Preventive Services Task Force, Lung Cancer: Screening — https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/lung-cancer-screening
• American Cancer Society, Statement on Updated USPSTF Lung Cancer Screening Guidelines — https://pressroom.cancer.org/Updated-USPSTF-LungCancerScreening-Guidelines
• NCI PDQ, Non-Small Cell Lung Cancer Treatment (Patient Version) — https://www.cancer.gov/types/lung/patient/non-small-cell-lung-treatment-pdq
• SEER Cancer Stat Facts, Lung and Bronchus Cancer — https://seer.cancer.gov/statfacts/html/lungb.html

How this article was prepared

An AI-assisted editorial system helped prepare this page. No named medical reviewer has reviewed it unless one is listed.

The National Cancer Information Foundation publishes Cancer Explained. This page is for learning. It is not medical advice and does not suggest a test or treatment.

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