Long-term follow-up of smokers following lung and colorectal cancer diagnosis

Abstract

Background: Continued smoking after a cancer diagnosis limits the effectiveness of treatment, increases the risk of cancer recurrence or secondary malignancies, and is associated with poorer quality of life and survival. A cancer diagnosis may provide a meaningful timepoint for quitting, but the prevalence and characteristics of continued smoking through survivorship are poorly understood.

Methods: In the multi-regional Cancer Care Outcomes Research and Surveillance (CanCORS) cohort, we examined smoking rates and factors associated with continued smoking at long-term follow-up among lung and colorectal cancer patients. This paper builds upon previous CanCORS participant data addressing quit rates and associated characteristics at baseline and 5 months post-diagnosis.

Results: At long-term follow-up (median 7.3 years post-diagnosis [IQR = 5.9-8.7]), 16.7% of lung cancer and 11.6% of colorectal cancer survivors continued to smoke combustible cigarettes. Factors independently associated with continued smoking at long-term follow-up included being male, younger, not married or partnered, having Medicare, Medicaid/other public or no insurance, more depression symptoms, smoking more cigarettes per day, and having a history of lung disease (p < .05). Continued smoking did not vary by lung vs. colorectal cancer diagnosis.

Conclusion: Of active smokers at the time of diagnosis, an important minority of lung and colorectal cancer survivors continued to smoke well into survivorship. Understanding characteristics associated with continued smoking after a cancer diagnosis may help inform the development of tobacco treatment programs for cancer patients and survivors.

Implications for survivors: While addressing smoking cessation at the time of diagnosis is critical to ensure better long-term treatment outcomes and quality of life, it is essential to continue smoking cessation discussions and efforts throughout care and survivorship.

Keywords: Cigarette smoking; Colorectal cancer; Lung cancer; Risk factors; Tobacco.