Smoking linked to lower survival in surgically treated colon cancer patients
Current smokers with colon cancer were significantly more likely to die within 5 years compared with patients who did not smoke, according to the results of a large population-based cohort study.
“This effect was limited to those patients who had cancer-directed surgery, suggesting that the mechanism by which smoking impacts on survival is in some way related to surgery,” Linda Sharp, PhD, professor of cancer epidemiology at the Institute of Health and Society at Newcastle University, U.K., and colleagues wrote.
Aiming to determine whether smoking status at the time of diagnosis is independently associated with colon cancer-specific survival, and whether this association varies with treatment (surgery vs. chemotherapy), Sharp and colleagues analyzed 18,166 colon adenocarcinoma cases diagnosed between 1994 and 2012 within the Irish National Cancer Registry.
Overall, 20% of patients were current smokers, 23% had quit smoking and 57% had never smoked. Further, 85% underwent cancer-directed surgery and 38% received chemotherapy.
Within 5 years of diagnosis, 7,488 patients died of cancer.
After adjusting for socio-demographic and clinical variables, the investigators found that current smokers had a 14% increased rate of cancer-specific death within 5 years compared with never smokers (HR = 1.14; 95% CI, 1.07-1.12).
However, they also observed a significant interaction between treatment and smoking (P = .034), and further analysis showed that only patients who underwent cancer-directed surgery had a significantly increased cancer-specific death rate compared with never smokers (HR = 1.21; 95% CI, 1.09-1.34).
Considering these data, it is important for physicians to “be aware that patient lifestyle factors can impact on cancer outcomes, but that it is possible to modify these behaviors,” Sharp told Healio Gastroenterology. “Physicians should encourage smokers diagnosed with cancer to engage with smoking cessation services and other supports.” – by Adam Leitenberger
Disclosures: The researchers report no relevant financial disclosures.