Factors Affecting Myocardial Infarction in Cervical Cancer Patients: A Population-Based Study

BACKGROUND Radiotherapy (RT) or concurrent chemoradiation therapy has been suggested to increase the risk of coronary heart disease for cervical cancer patients, but the results of studies have been inconsistent. Therefore, we aimed to investigate the factors which influence the risk of developing myocardial infarction (MI) in cervical cancer patients with a large, nationwide cohort. METHODS The study analyzed data from the 1996 to 2010 National Health Insurance Research Database provided by the National Health Research Institutes in Taiwan. The assessed number of patients with cervical cancer with radiotherapy only, surgery with bilateral oophorectomy only, and with appendectomy were 308, 323 and 229, respectively. The Kaplan-Meier method and the Cox proportional hazards model were used to assess the risk of myocardial infarction. RESULTS The adjusted hazard ratio for cervical cancer in patients with MI was 1.97 (95% CI, 0.97 - 3.91; P = 0.05) for the group that received RT alone, and 2.13 (95% CI, 1.11 - 3.75; P = 0.01) for the surgery group when compared with controls. The more risk comorbidities they have, the higher the risk of myocardial infarction would be for the patients. CONCLUSION The incidence of MI was significantly higher among cervical cancer patients with RT alone or surgery with bilateral oophorectomy alone than among general populations. RT might be as a factor to increase risk as bilateral oophorectomy. Whether RT itself triggers menopause or impairs the ovarian hormone production that increases the risk of MI needs to be further investigated.