Cancer risk in patients with manifest vascular disease: effects of smoking, obesity, and metabolic syndrome.
Patients with vascular disease may be at increased risk of cancer because of shared risk factors and common pathogenesis. Patients with vascular disease (n = 6,172) were prospectively followed for cancer incidence. Standardized incidence ratios (SIRs) were calculated to compare the cancer incidence of the study population with that of the general population. Multivariable-adjusted hazard ratio's (HRs) of cancer were estimated for smoking status, pack-years, body mass index, waist circumference and visceral adipose tissue (VAT), and metabolic syndrome (MetS). During a median follow-up of 5.5 years, 563 patients were diagnosed with cancer. Patients with vascular disease were at increased risk of cancer [SIR = 1.19; 95% confidence interval (CI), 1.10-1.29]. Specifically, risk of lung cancer (SIR = 1.56; 95% CI, 1.31-1.83), as well as bladder cancer (SIR = 1.60; 95% CI, 1.11-2.24) and cancer of the lip, oral cavity, or pharynx in men (SIR = 1.51; 95% CI, 0.89-2.39), and colorectal (SIR = 1.71; 95% CI, 1.11-2.53) and kidney cancer (SIR = 2.92; 95% CI, 1.05-6.38) in women was increased. A relation between smoking and cancer risk was observed (HR for current smokers = 1.37; 95% CI, 1.05-1.73), whereas an increase in VAT was associated with higher breast cancer risk in women (HR = 1.42; 95% CI, 1.03-1.96). No relation between MetS and cancer risk was found. Patients with vascular disease have a 19% higher cancer risk compared to the general population. Smoking increased cancer risk and abdominal obesity is a risk factor for breast cancer in female patients with vascular disease. These results call for awareness of the increased cancer risk in patients with vascular disease among physicians and underline the necessity of lifestyle improvement not only for reducing cardiovascular risk.