Smoking Cessation in Patients With Cancer

This randomized controlled trial will evaluate whether adding one-session structured cognitive behavioral therapy (CBT)-based smoking-cessation counseling to standardized brief smoking-cessation counseling improves cigarette smoking abstinence among patients with cancer who smoked combustible cigarettes at diagnosis and are still smoking at screening and enrollment. After written informed consent and baseline assessment, all participants will receive the same standardized brief smoking-cessation counseling using a condensed 5A framework. Participants will then be randomly assigned 1:1 to no additional study CBT or to one additional structured CBT-based smoking-cessation session. Follow-up will continue for 3 months after randomization at Campus 3 of Vietnam National Cancer Hospital in Hanoi, Vietnam.

Inclusion Criteria: 1. Aged 18 years or older. 2. Diagnosed with cancer. 3. Was smoking combustible cigarettes at the time of cancer diagnosis. 4. Still smoking combustible cigarettes at screening/enrollment. 5. Able to communicate sufficiently and provide reliable study information. 6. Provides written informed consent. Exclusion Criteria: 1. Clinically too severe for reliable participation. 2. Cognitive/communication limitations precluding consent or reliable participation. 3. Currently participating in a competing structured smoking-cessation program. 4. Concurrent use of tobacco/nicotine products other than combustible cigarettes (e-cigarette, heated tobacco product, waterpipe/shisha, cigar, pipe, smokeless tobacco, etc.). Outside therapeutic NRT/cessation medications are not an exclusion.