A new study entitled “Active Smoking and Mortality Among Colorectal Cancer Survivors: The Cancer Prevention Study II Nutrition Cohort” reports that colorectal cancer survivors who smoke cigarettes have double risk of dying when compared to non smokers of either all-cause or colorectal cancer–specific mortality. The study was published in the Journal of Clinical Oncology.
In this study, a team of researchers at the American Cancer Society National Home Office investigated how active smoking impacted colorectal patients survival after their diagnosis. While it was known that active smoking is a high risk factor for colorectal cancer, its impact on patients’ survival after diagnosis was generally unknown.
The authors investigated how smoking associated with all-cause and colorectal cancer–specific mortality before and after colorectal cancer diagnosis. To this end, the team identified 2,548 individuals diagnosed with invasive nonmetastatic colorectal cancer from the American Cancer Society’s Cancer Prevention Study II and determined smoking habits (available from 2,256 patients, thus 88.5%), vital status and cause of death. From the pool of 2,548 colorectal cancer survivors, 1,074 died during the study follow up, 453 of which associated with a colorectal cancer–specific death.
The authors determined that patients who smoked before diagnosis exhibited twice as much higher risk for all-cause mortality and colorectal cancer–specific mortality; former smoking was also associated with an increased rate for all-cause mortality, however, the same was not observed with specific colorectal cancer mortality. Additionally, the team determined that current-smoking habits after diagnosis was also associated with both an increased risk for overall mortality (twice as more), as well as colorectal cancer-specific mortality (almost doubling the risk).
The authors highlighted that smoking renders patient’ tumors more aggressive and it diminishes the efficacy for colorectal cancer therapeutics; however, further studies are necessary to understand the mechanisms of how smoking actually impacts the disease course. These findings confirm previous evidence that indeed cigarette smoking is associated with increased non-metastatic colorectal cancer mortality.