Smoking cessation after MI reduces risk of cancer
Smoking cessation may help lower the risk of cancer, according to a recent study involving young survivors of first myocardial infarction (MI) followed-up longitudinally. Moreover, reducing cigarette smoking may be beneficial.
To assess long-term incidence of cancer after MI among current, former and never smokers, researchers followed consecutive patients aged ≤65 years discharged from eight hospitals in central Israel after MI in 1992 to 1993 for cancer and death.
They collected extensive data, including smoking habits, at the index hospitalization and four time points during follow-up. Survival methods were used to evaluated the hazard ratios (HRs) for cancer associated with smoking categories.
Of the 1,486 cancer-free participants (mean age 54 years; 81 percent men), 787 were current smokers at baseline (average daily cigarette consumption, 29). Smokers were younger than nonsmokers, more likely to be male and of lower socioeconomic status.
A total of 273 patients (18.4 percent) developed cancer over a median 21.4 years of follow-up. An association existed between baseline smoking and an approximately 40-percent excess adjusted risk of cancer. After accounting for death as a competing event, baseline smoking correlated with about 25-percent excess risk of cancer.
When changes in smoking were considered during follow-up, the excess risk was found to be limited to persistent smokers (adjusted HR, 1.75; 95 percent CI, 1.22 to 2.50). On the other hand, post- (HR, 1.14; 0.80 to 1.62) and pre-MI quitters (HR, 1.02; 0.71 to 1.47) were comparable with never smokers.
In relation to pre-MI consumption, each reduction of 10 cigarettes among persistent smokers correlated with about 10-percent lower adjust risk of cancer.