Abstract
PURPOSE: Psychiatric disorders and cancer are both common, and comorbidity has detrimental impacts on cancer outcomes. Previous studies focus on affective disorders which arise after cancer diagnosis, not on the impact of psychiatric disorders on cancer risk. We investigate the association between psychiatric disorders and subsequent gastrointestinal cancer in a large cohort in Germany. METHODS: This case-control study used secondary data (electronic medical records) from the national IQVIA Disease Analyzer database. We evaluated the association between previous psychiatric diagnosis in 44,582 matched patients with and without gastrointestinal (GI) cancer. Regression analyses were stratified by psychiatric diagnosis and adjusted by chronic comorbidities and previous psychiatric treatments. RESULTS: No association between any previous psychiatric disease and GI cancers was found (OR = 0.98 (0.95-1.02 95%CL, p = 0.39). Previous psychosomatic disorder and GI cancer showed a significant negative association (OR: 0.86, 0.81-0.90 95%CL, p < 0.0001). No association was found between previous diagnosis with depression or PTSD and GI cancer. These results remained consistent when including previous psychiatric treatments in the regression analyses. CONCLUSION: Psychiatric disease was not associated with GI cancer risk. Further investigation into the pathways linking psychiatric disease and cancer needs to be conducted, taking into consideration psychiatric treatments administered, to enhance our understanding of the relationship between these two common and devastating diseases.