Continued smoking after a cancer diagnosis: a longitudinal study of intentions and attempts to quit

Continued smoking after a cancer diagnosis is associated with poor treatment outcomes and reduced life expectancy. We aimed to identify the stability of smoking status after diagnosis including quit attempts and quit intentions.

Participants with a first primary cancer diagnosis were recruited via two state-based registries in Australia. Questionnaires were mailed at approximately 6 months (T1), 1 year (T2), 2 years (T3), and 3.5 years (T4) post-diagnosis. Smoking status and quitting intentions were assessed at each time point.

A cohort of 1444 people was recruited. People who indicated that they were more than 9 months post-diagnosis are excluded from analysis, leaving 1407 eligible study participants. Sixty-six (37%) of the 178 self-reported smokers at diagnosis had quit in the 6-month post-diagnosis (T1), the remaining 112 (63%) reported being a current smoker. Of the smokers at T1, 40% intended to quit: with 8% having quit smoking by T2; 11% quit by T3; 12% quit by T4. Of those who reported at T1 that they intended to quit in the next 6 months, 10% or fewer reported having quit at any subsequent time point. Quitting attempts decreased in frequency over time post-diagnosis. Less than 15% of respondents who had quit at or shortly before diagnosis reported relapse to smoking at each time point.

The majority of smokers diagnosed with cancer continue to smoke beyond diagnosis, even in the context of an intention to quit and attempts to do so. Cancer survivors who smoke remain motivated to quit well beyond the initial diagnosis.

There are clear positive clinical effects of smoking cessation for those who have undergone treatment for cancer, both for short-term treatment outcomes, and for long-term survivorship. Given the substantial rates of continued smoking among those who report smoking at diagnosis and their continued attempts to quit during survivorship, there is a need for improved cessation support initiatives for people diagnosed with cancer. These initiatives need to continue to be offered to smokers long after the initial diagnosis and treatment.