Aims

This study explored the association of coronary artery calcium (CAC) with incident cancer subtypes in the Multi-Ethnic Study of Atherosclerosis (MESA). CAC is an established predictor of cardiovascular disease (CVD), with emerging data also supporting independent predictive value for cancer. The association of CAC with risk for individual cancer subtypes is unknown.

Methods and results

We included 6271 MESA participants, aged 45-84 and without known CVD or self-reported history of cancer. There were 777 incident cancer cases during mean follow-up of 12.9 ± 3.1 years. Lung and colorectal cancer (186 cases) were grouped based on their strong overlap with CVD risk profile; prostate (men) and ovarian, uterine, and breast cancer (women) were considered as sex-specific cancers (in total 250 cases). Incidence rates and Fine and Gray competing risks models were used to assess relative risk of cancer-specific outcomes stratified by CAC groups or Log(CAC+1). The mean age was 61.7 ± 10.2 years, 52.7% were women, and 36.5% were White. Overall, all-cause cancer incidence increased with CAC scores, with rates per 1000 person-years of 13.1 [95% confidence interval (CI): 11.7-14.7] for CAC = 0 and 35.8 (95% CI: 30.2-42.4) for CAC ≥400. Compared with CAC = 0, hazards for those with CAC ≥400 were increased for lung and colorectal cancer in men [subdistribution hazard ratio (SHR): 2.2 (95% CI: 1.1-4.7)] and women [SHR: 2.2 (95% CI: 1.0-4.6)], but not significantly for sex-specific cancers across sexes.

Conclusion

CAC scores were associated with cancer risk in both sexes; however, this was stronger for lung and colorectal when compared with sex-specific cancers. Our data support potential synergistic use of CAC scores in the identification of both CVD and lung and colorectal cancer risk.

Background and aims

Coronary artery calcium (CAC) scores have been shown to be associated with CVD and cancer mortality. The use of CAC scores for overall and lung cancer mortality risk prediction for patients in the Coronary Artery Calcium Consortium was analyzed.

Methods

We included 55,943 patients aged 44-84 years without known heart disease from the CAC Consortium. There were 1,088 cancer deaths, among which 231 were lung cancer, identified by death certificates with a mean follow-up of 12.2 ± 3.9 years. Fine-and-Gray competing-risk regression was used for overall and lung cancer-specific mortality, accounting for the competing risk of CVD death and after adjustment for CVD risk factors. Subdistribution hazard ratios (SHR) were reported.

Results

The mean age of all patients was 57.1 ± 8.6 years, 34.9% were women, and 89.6% were white. Overall, CAC was strongly associated with cancer mortality. Lung cancer mortality increased with increasing CAC scores, with rates per 1000-person years of 0.2 (95% CI: 0.1-0.3) for CAC = 0 and 0.8 (95% CI: 0.6-1.0) for CAC ≥400. Compared with CAC = 0, hazards were increased for those with CAC ≥400 for lung cancer mortality [SHR: 1.7 (95% CI: 1.2-2.6)], which was driven by women [SHR: 2.3 (95% CI: 1.1-4.8)], but not significantly increased for men. Risks were higher in those with positive smoking history [SHR: 2.2 (95% CI: 1.2-4.2)], with associations driven by women [SHR: 4.0 (95% CI: 1.4-11.5)].

Conclusions

CAC scores were associated with increased risks for lung cancer mortality, with strongest associations for current and former smokers, especially in women. Used in conjunction with other clinical variables, our data pinpoint a potential synergistic use of CAC scanning beyond CVD risk assessment for identification of high-risk lung cancer screening candidates.