Smoking and malignant disease: a general practice study.

This study, involving a practice population of 7,200 patients, compared the smoking habits of patients suffering from malignant disease (excluding skin cancer) with the smoking habits of controls matched for age and sex. Patients with malignancies were found to smoke more heavily than their controls; this difference was particularly marked between the younger patients and their controls. Data on the most prevalent malignancies (carcinomata of the breast, cervix, rectum, colon and bladder) revealed that this tendency to heavier smoking was more marked in patients with neoplasia of cervix or bladder than in patients with breast or colorectal neoplasms. The age of these patients at diagnosis was reviewed in relation to smoking habits. Although the numbers were small, it appeared that patients who smoke present at an earlier age than non-smokers, except in cases of neoplasia of the cervix.These results seem to justify further general practice studies into the links between smoking and malignant disease.