According to research results in the current issue of Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research, patients who continue to smoke after a cancer diagnosis experienced a 59% increase in accelerated mortality, compared to those who kicked the habit after learning about their disease.

When limited to men who were smokers at diagnosis, those who continued smoking after diagnosis had a 76% increase in risk of accelerated mortality compared with those who quit smoking after a diagnosis.

For those who continued smoking, how much the risk of death increased varied by diagnosis: the uptick was 2.95-fold for bladder cancer patients, 2.36-fold for lung cancer patients, and 2.31-fold for colorectal cancer patients.

“Many cancer patients and their health care providers assume that it is not worth the effort to stop smoking at a time when the damage from smoking has already been done, considering these patients have been diagnosed with cancer,” said Li Tao, MD, MS, PhD, epidemiologist at the Cancer Prevention Institute of California in Fremont. “Our study provides evidence of the impact of post-diagnosis smoking on survival after cancer, and assists in addressing the critical issue of tobacco control in cancer survivorship.”

Using data from the Shanghai Cohort study, investigators evaluated the association between lifestyle characteristics and risk of cancer among middle-aged and older men in Shanghai, China. Patient information was collected through an in-person interview-based questionnaire about demographics, history of tobacco and alcohol use, diet, and medical history. Data were updated on an annual basis for all surviving cohort members.