Relation of Coronary Artery Calcium Score and Risk of Cancer (from a Danish Population-Based Follow-up Study in Patients Who Underwent Cardiac Computed Tomography)

Evidence of a causal link between atherosclerosis and cancer is sparse and conflicting. Therefore, we examined the association between extent of coronary atherosclerosis determined by coronary artery calcium score (CACS) and risk of cancer. We conducted a historical population-based cohort study of 28,549 cancer-free patients identified in the Western Denmark Heart Registry. All patients underwent cardiac computed tomography for measurement of CACS for suspected coronary artery disease. The outcome was an incident cancer diagnosis: total, tobacco-related, lung, prostate, breast, and colorectal. We used Cox proportional hazards regression analyses stratified by gender to estimate hazard ratios (HRs) for relations between CACS and cancer with 95% confidence intervals (95% CI). During follow-up, 455 men and 527 women had a cancer diagnosis. In a multivariable model (reference group: CACS 0), adjusted hazard ratios (95% confidence interval) for total cancer were as follows: CACS 1 to 99: 1.07 (0.83 to 1.39), CACS 100 to 399: 1.24 (0.94 to 1.63), CACS 400 to 999: 0.88 (0.62 to 1.25), CACS ≥1,000: 0.96 (0.66 to 1.41) in men; and CACS 1 to 99: 0.96 (0.77 to 1.19), CACS 100 to 399: 0.99 (0.75 to 1.31), CACS 400 to 999: 1.11 (0.76 to 1.62), and CACS ≥1,000: 1.16 (0.73 to 1.83) in women. We found no significant association between CACS and the specified outcomes for men or women, except for an increased risk of lung cancer among women with a high CACS. In conclusion, extent of coronary atherosclerosis determined by CACS was not associated with development of total, tobacco-related, lung, prostate, breast, or colorectal cancer. However, we did observe an association between CACS and risk of lung cancer in women.