CASTL Trial & Lung Cancer Screening: Quit-Smoking Support in 2026

If you’re eligible for lung cancer screening and you smoke, your visit may be more than a CT scan. A July 8, 2026 report from the CASTL (Cessation and Screening to Save Lives) optimization trial looks at how to fit evidence-based quit-smoking support into the screening workflow—especially for people who are not ready to quit right away.

What’s new from July 8, 2026: CASTL tests cessation support inside lung screening

CASTL is an optimization randomized clinical trial conducted at 17 U.S. lung cancer screening sites. People scheduled for low-dose CT lung cancer screening and who currently smoked were randomized to one of 16 combinations of smoking-cessation components. The primary outcome was self-reported abstinence at 6 months, and the study also estimated the cost of each combination.

At enrollment (N=758), about 5% of participants were not interested in quitting, 59% were considering quitting, and 38% had already started making changes. Most participants (about 79%) reported smoking within 30 minutes of waking, suggesting a high level of nicotine dependence.

What CASTL found (and what it can’t prove)

In the abstract results, the study reported no significant differences among the tested intervention components. Because this is an optimization study, the analysis also focused on which combinations might be most “value-efficient”—balancing expected abstinence with estimated cost.

Most value-efficient option (expected abstinence + cost): loss-framed messaging plus nicotine patch/lozenge (expected abstinence rate 30%; mean cost $287.41).
Among lower-cost options: gain-framed messaging only (expected abstinence 13%; mean cost $51.29).

How to interpret this: CASTL can help screening programs decide which quit-smoking “ingredients” may be practical to deliver. But it does not guarantee that every site will see the same results, or that any one message + medication package will be best for every patient.

Why this matters in lung cancer screening—tobacco dependence is chronic

Lung cancer screening reaches people at high risk because of their smoking history. Quitting smoking can be hard and often takes repeated support. The CDC emphasizes that tobacco use and dependence is a chronic, relapsing condition that frequently requires ongoing, evidence-based treatment—not just a single conversation.

What evidence-based tobacco-cessation care looks like (and how it fits screening visits)

CDC: counseling + FDA-approved medication

The CDC describes clinical interventions that can help adult patients quit, including:

Behavioral counseling (in person, group, over the phone/quitlines, and via text/web programs).
FDA-approved medications for smoking cessation, including nicotine replacement therapies (patch, gum, lozenge) and prescription options (varenicline and bupropion).
Combining treatments: counseling and medication together can improve quit success compared with either approach alone.

VA/DoD (2026): motivational interviewing, intensive counseling, and treating even when not ready

The 2026 VA/DoD Tobacco Use Treatment Provider Summary includes practical recommendations that map well to screening-program settings:

Motivational interviewing to increase engagement in treatment.
More intensive counseling (at least four encounters).
FDA-approved pharmacotherapies (for increasing abstinence from combustible tobacco).
For people not ready to quit in the next 30 days: the guideline suggests offering nicotine replacement therapy and/or varenicline to increase quit attempts and abstinence over time.

Medicare: the pre-screening visit is a built-in “shared decision” moment

For Medicare Part B, lung cancer screening is covered once a year for people who meet criteria (including age 50–77, no signs/symptoms of lung cancer, current smoker or quit within the last 15 years, and a smoking history of at least 20 pack-years). Medicare also notes that before the first screening, you must schedule an appointment to discuss the benefits and risks and decide if screening is right for you.

Medicare also states you pay nothing for the screening test itself if your provider accepts assignment. Costs for cessation counseling and medications can vary by plan and setting, so it’s reasonable to ask what’s covered where you’ll be screened.

Questions to ask your screening team (to connect screening with quitting support)

“Do you offer tobacco-cessation counseling at the screening visit, or referral to quitlines/programs?”
“Can I get FDA-approved quit-smoking medication support if I’m willing to try it—even if I don’t have a quit date yet?”
“How many follow-up counseling encounters are typically available?” (VA/DoD suggests at least four.)
“What should I expect for side effects and follow-up if I start a medication?”
“Where can I find additional support if my first quit attempt doesn’t stick?”

If you’ve ever felt awkward bringing up smoking, you can simply say: “I want to quit, but I’m not sure where to start.” Many programs are set up to support engagement and ongoing attempts.

What remains uncertain about CASTL for everyday practice

Optimization ≠ guaranteed superiority: the abstract reports no statistically significant differences among components, so the “value-efficient” results depend on how costs and expected abstinence were modeled.
Primary outcome was self-reported at 6 months: self-report can differ from biochemical verification.
Fit depends on resources: screening sites vary in staffing and access to structured tobacco treatment, which can affect how closely real-world delivery matches the trial.

Still, CASTL’s core idea is practical: build evidence-based cessation support into lung cancer screening programs in a way that’s efficient enough to scale—and tailored enough to reach people considering quitting.

Sources

Editorial note: Weence articles are researched from cited public-health, medical, regulatory, journal, and reputable news sources and may be drafted with AI assistance. They are checked for source support, clarity, and safety guardrails before publication.

This article is for general informational purposes only and is not medical advice. Research findings can be early or incomplete, and health guidance can change. Always talk with a qualified healthcare professional about personal symptoms, diagnosis, medications, vaccines, screenings, or treatment decisions. If you think you may have a medical emergency, call emergency services right away.