Cancer risk in major psychiatric diseases

• Main Authors: Chen, Yu-Jung, 陳俁榮
• Other Authors: Li, Yi-Hwei
• Format: Others
• Language: en_US
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/vhh2z8

博士 === 慈濟大學 === 醫學科學研究所 === 105 === Background: Patients with major psychiatric disorders are usually less healthy in many aspects. It is intriguing to explore whether cancer risk is also increased in the three major disease categories-- schizophrenia, bipolar disorder, dementia exemplified by Alzheimer’s disease (AD) and Parkinson’s disease dementia (PDD). Most prior studies focused on schizophrenia, but the results are conflicting. Stratified analysis concerning gender, age-of-onset, disease duration and diagnostic state (before or after diagnosis) may clue us about how the cancer risks can vary across the whole life span. Relative to schizophrenia, studies on the cancer risk in bipolar disorder, MDD, AD and PDD are limited. Comparing the risk patterns can be illuminating enough to formulate further pathophysiological hypotheses. Methods: This study used the Taiwan National Health Insurance Research Database. A total of 74,448 schizophrenia patients from 1995 to 2009; 20,567 bipolar disorder patients, and 15,800 AD patients and 2,527 PDD patients from 1997 to 2010 were enrolled. All the four cohorts were followed up for cancer during the same period by record linkage with the cancer certification in Taiwan. Age and gender standardized incidence ratios (SIRs) of overall and site-specific cancers were calculated. Results: The before-schizophrenia-diagnosis SIR for all cancers was 0.58 (95% CI: 0.52-0.65) wherein male SIR was 0.36 (95% CI: 0.30-0.44); female SIR 0.77(95% CI: 0.68-0.88). The overall-before-and-after- schizophrenia-diagnosis SIR was1.14 (95% CI: 1.07-1.21) wherein male SIR was 0.94 (95% CI: 0.85-1.04), female SIR 1.3 (95% CI: 1.19-1.41). For the bipolar disorder cohort, the SIR for all cancers was 1.29, but the excess risk was found in males (SIR: 1.42, 95% CI: 1.14-1.77); not females. Both AD and PD, like chronic or latent schizophrenia patients, were at a lower risk for total cancers (SIR: 0.83 vs 0.69). Conclusions: Schizophrenia patients were protected from cancers before schizophrenia diagnosis, but the protection lost as schizophrenia evolved in female patients. Schizophrenia and bipolar disorder differ in gender-specific cancer risks which result in the increased overall cancer risk. Although both AD and PDD patients have decreased cancer risk, the protection appears stronger in PDD than AD. Key words: major psychiatric disorders, schizophrenia, bipolar disorder, Alzheimer’s disease, Parkinson’s disease dementia, cancer, standardized incidence ratio