Introduction:
To assess the smoking behaviour of Lung Cancer (LC) and Colorectal (CRC) patients at the time of diagnosis and one year after diagnosis.

Material and Methods:
The study took place in the island of Crete, Greece. Data (LC patients=4,421; CRC patients=3,609) were derived from the Cancer Registry of Crete (1992-2010). Participants with I-III stage primary cancer and confirmed diagnosis (histologically/cytologically) were included. Patients with unknown stage were excluded after testing for potential statistical bias. Kruskal-Wallis (one-way analyses of variance) and logistic regression models estimated the risk of not quitting smoking after diagnosis. All tests were two-tailed (a=0.05).

Results:
Overall, 75.1% of LC and 51.4% of CRC patients were current smokers at the time of diagnosis. One year after diagnosis 49.5%% of the LC and 38.1% of the CRC patients were still smoking. Males, public insurance, high number of pack/years, not receiving chemotherapy/radiotherapy, not undergoing surgery, higher number of co-morbidities, advanced cancer stage (III) and alcohol consumption were significant predictors of not quitting smoking one year after diagnosis (p<0.05) among LC patients. In CRC patients, the above parameters were significantly associated, although the risk was higher for uninsured patients or patients with private insurance. Additionally, disease stage wasn’t found to have an impact on CRC patients smoking habits upon diagnosis.

Conclusions:
The study findings highlight the urgent need of addressing more effectively tobacco treatment in cancer patients who are smokers. Physician’s role should be enhanced towards smoking cessation while integration with anti-smoking centers is considered crucial.