BACKGROUND: The postprocedural state after cardiac revascularization interventions is characterized by intense inflammation and activation of inflammatory cytokines due to myonecrosis and ischemia/reperfusion injury. Involvement of similar processes also participates in cellular malignant transformation. In this study, the association between cardiac interventions and subsequent cancer risk development was therefore evaluated.
METHODS: The 5-year cumulative incidence of cancer was examined in 2 cardiac care cohorts: all patients undergoing either open heart surgery or percutaneous coronary interventions (PCI) at hospitals in the commonwealth of Massachusetts. The observed cases of cancer were compared with the number of expected cases based on the state cancer rates, adjusting for sex and 5-year age groups. The standardized morbidity ratio (SMR) was used for this comparison.
RESULTS: Of 10,301 patients in the surgical cohort, 804 (7.8%) incident cancers developed over 5 years of follow-up, whereas 245.7 incident cancers were expected. This yielded an SMR of 3.27 (95% CI, 3.05-3.51; P<0.0001). In the PCI cohort comprising 13,001 patients, 1029 (7.9%) incident cancers developed over 5 years, resulting in an SMR of 3.53 (95% CI, 3.32-3.75; P<0.0001). Excluding respiratory cancers from the analysis (to limit smoking-related cancers) reduced risk estimates only slightly. For the surgical cohort: SMR=2.80; 95% CI, 2.59-3.01; P<0.0001. For the PCI cohort: SMR=2.97; 95% CI, 2.78-3.18; P<0.0001.
CONCLUSIONS: Undergoing heart revascularization procedures was associated with increased rate of cancer development as compared with the state general population. This cohort may warrant increased monitoring.