Prevalence and determinants of quitting smoking after cancer diagnosis: a prospective cohort study.

To describe smoking behaviours of patients with incident cancer attending an Italian cancer centre and to examine changes in their smoking habits within 12 months from cancer diagnosis, evaluating determinants of smoking cessation. A hospital-based prospective cohort included patients hospitalized in an Italian cancer centre (2016-2018). Patients were mostly female (74%) and included a limited proportion of aerodigestive cancers (7%). Face-to-face interviews were performed during hospital stay to gather information on patient characteristics and smoking history. Changes in smoking habits were assessed through telephone interviews at 3, at 6, and at 12 months after cancer diagnosis. Among 1011 enrolled patients, 222 (22%) were current smokers at cancer diagnosis. Smoking prevalence was high in male patients (30%), in patients <50 years old (28%), in those with aerodigestive cancers (50%), and in those diagnosed at advanced stages (26%). Among current smokers at cancer diagnosis, 38% quit smoking after 12 months, 26% reduced intensity, and 36% did not modify smoking habits. Smoking cessation was associated with chemotherapy and, although not statistically significant, with female sex, older age, and advanced cancer stage. Patients with gastrointestinal, breast, or genitourinary cancer and those treated with surgery were less likely to quit smoking. Our results highlighted that 62% of smoking patients with cancer did not quit the habit. Smoking cessation programs targeted to patients with cancer need intensification, particularly for those who may underestimate smoking effects after diagnosis.