Cancer Incidence of Schizophrenic Patients in Taiwan, 1997-2009: A Nationwide Population-Based Study

• Main Authors: Gen-Min Lin, 林耕民
• Other Authors: Yi-Hwei Li
• Format: Others
• Language: en_US
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/79157493500837721478

碩士 === 慈濟大學 === 公共衛生學系碩士班 === 100 === Background Numerous reports demonstrated conflicting results regarding the cancer incidence among schizophrenic patients. Both genetic and environmental factors have been reasoned for the disparities. However, the influence of age-of-onset and duration-of-schizophrenia on cancer risk has rarely been emphasized. We aimed to elucidate the relationship between cancer risk and age-at-diagnosis as well as duration-of-schizophrenia. Methods This study used data from the Taiwan National Health Insurance Research Database. A total of 71,317 patients with newly diagnosed schizophrenia from 1997 to 2009 were recruited. Patients were followed up for cancer during the same period by record linkage with the cancer certification in Taiwan. Age- and gender- standardized incidence ratios (SIR) of overall and site-specific cancers for schizophrenic patients relative to Taiwanese general population were calculated. Results There were 1,129 cancers observed over a total follow-up of 474,074 person-years (the mean follow-up period was 6.65 years). The SIR for total cancer was 1.17 (95% confidence interval (CI): 1.11-1.32) indicating an increased risk of cancer among schizophrenic patients. Only female patients had an increased risk for cancer (SIR: 1.31, 95% CI: 1.17-1.48, p-value for gender difference=0.005). Among all patients, cancer risk gradually reduced with disease chronicity and older onset age. In patients diagnosed before 50, the SIRs for colorectal, breast, cervical and uterine cancers increased significantly, whereas in patients diagnosed after 50, the SIRs for almost all cancers decreased except for breast cancer. Conclusions For schizophrenic patients in Taiwan, overall cancer risk was inversely associated with age-at-diagnosis and disease duration. These findings deserve further medical attention.