Colon cancer prognosis is associated with prior smoking and genetic mutations

This study compared disease free survival (the time period between the end of treatment and until the disease returns or the patient relapses) for colon cancer patients with a history of smoking versus non-smokers.

Cigarette smoking can increase the risk of colon cancer. However, it is not clear how prior smoking history influences a patient’s prognosis once colon cancer has been diagnosed. Furthermore, genetic mutations associated with colon cancer, such as BRAF and KRAS, can influence prognosis, but the relation between these and smoking is still unclear. This study aimed at revealing whether smoking status and genetic mutations could have a combined effect that influences survival.

To assess how smoking and mutation status interact, researchers compared 1,749 colon cancer patients. Patients completed a lifestyle questionnaire before receiving treatment. All of the patients’ tumors were checked to assess the genetic makeup.

Overall, patients with a history of smoking cigarettes experienced a shorter disease free survival time than non-smokers. However, this did not hold true for cancers with mutations in the BRAF gene. Smokers with KRAS mutations were shown to experience a shorter survival time than smokers without KRAS mutations (however this was not as statistically significant as the rest of the findings).

Overall, in colon cancer patients, smoking is associated with shorter disease free survival times. This however depends in part on the genetic makeup of the cancer. A new finding in this study was that a history of smoking only affects the prognosis of patients without BRAF genetic mutations.

Consult with your physician on how to quit smoking and improve survival in the case of colon cancer.