Cancer Diagnosis and Suicide Mortality: A Systematic Review and Meta-Analysis

Cancer is one of the most common diseases and suicide is one of the causes of cancer patients' mortality. However, the suicide mortality rate in cancer patients has not been thoroughly investigated. The aim of this study was to perform a systematic review and a meta-analysis of suicide mortality risk in cancer patients. The authors systematically searched PubMed, Scopus, psycInfo, and Google Scholar databases using MESH keywords until July 2018; searching was limited to English. Random effects model was used for meta-analyzing the studies. Forest plot was calculated for the whole of the 22 studies and the subgroups. Publication bias was examined, and qualitative evaluation of the articles entered into the meta-analysis was also carried out. 22 studies were included in the meta-analysis. Pooled Standardized Mortality Ratio (SMR) for suicide mortality (SMR = 1.55; 95% and confidence interval (CI) CI = 1.37-1.74) in cancer patients were achieved. It has been shown (SMR = 1.67; 95% CI = 1.48-1.89 and p<0.001) that cancer has increased suicidal rates in men and also in women (SMR = 1.34; 95% CI = 1.20-1.50 and p<0.001). The following results were reported based on the subtypes of cancer; pooled SMR = 2.06; 95% CI = 1.32-3.23, and p<0.001 in esophagus, stomach, pancreas and liver cancers; SMR = 1.57; 95% CI = 1.26-1.97, and p<0.001 in colon and rectum cancers; SMR = 3.07; 95% CI = 2.20-4.28, and p<0.001 in bronchus, trachea and lung cancers; SMR = 1.24; 95% CI = 1.03-1.48, and p=0.020 in breast cancer; SMR = 1.71; 95% CI = 1.38-2.12, and p<0.001 in prostate cancer. Overall, there is an evaluated suicide mortality rate in cancer patients. There was some evidence of publication bias. Our findings indicate that cancer increases the risk of suicide. Given the results and co-morbidities between suicide-induced cancer and other psychological disorders, the development of psychological interventions can be useful in reducing the risk of suicide in these patients.