Risk for non-smoking-related cancer in atherosclerotic patients

Some studies have suggested that the pathogenesis of atherosclerosis and that of cancer have common features, and in addition to tobacco smoking, oxidative stress, diet, and sex hormones have been considered as common etiological factors. To investigate whether there is an association between atherosclerosis and cancer, we evaluated the cancer pattern of patients with atherosclerosis of the aorta and of peripheral and cerebral vessels. A total of 69,485 patients with atherosclerosis were identified through the Danish National Registry of Patients between 1977 and 1989, and the incidence of cancer in this group was calculated by linkage to the Danish Cancer Registry for the period 1977-1993. No consistent excesses over the expected figures were seen for cancer at any site unrelated to tobacco smoking in either the total cohort or in subgroups. Specifically, we found no association at the individual level between atherosclerosis and colorectal cancers or hormone-related cancers, except from a decreased standardized incidence ratio of 0.7 (95% confidence interval, 0.5-0.9) for endometrial cancer. The standardized incidence ratio for cancers of the brain and nervous system was 1.1 (95% confidence interval, 0.9-1.3) for all patients combined, whereas patients with atherosclerosis of precerebral or cerebral arteries had a slightly increased risk (40%) for cancers of the brain and nervous system. The excess was seen only during the initial 3 years after discharge from hospital, and the likely explanation was a missed diagnosis. The study does not support the view that patients with atherosclerotic diseases represent a high-risk group for prostate cancer and potential future targets for prostate cancer screening interventions.