Cancer: Mental health and suicide risk among adults with cancer examined

Patients with cancer who are diagnosed with a psychiatric disorder had a higher incidence of mortality and are at greater risk of self-harm compared with other patients with cancer, according to a paper published in Nature Medicine. A second paper finds that patients with cancer have a nearly 2-fold greater risk of dying by suicide than the general population. These findings are based on the largest population-based analyses of the total burden of mental illness and self-harm events across major adult cancers thus far.

Despite progress in cancer therapy and prognosis in recent decades, patients with cancer are persistently at a high suicide risk. However, the impact of mental health on suicide and survival outcomes in cancer remains unclear, largely due to a lack of studies with sufficient sample sizes to demonstrate such effects.

Alvina Lai and Wai Hoong Chang analyzed population-based data from two large electronic health record databases covering a period of almost 23 years to examine instances of psychiatric disorders and self-harm across 26 cancer types (among 459,542 people 18 years of age and up). The authors found that depression is the most common psychiatric disorder in patients with cancer and that the highest cumulative burden of psychiatric disorders is associated with receiving chemotherapy, radiotherapy, surgery and alkylating agents (used in certain cancer treatments), and with testicular cancer. Psychiatric disorders (such as depression, anxiety disorders, schizophrenia, bipolar disorders and personality disorders) were associated with an increased risk of mortality of any kind and increased risk of self-harm within 12 months of a mental illness diagnosis.

In a separate study, Corinna Seliger and colleagues performed a systematic review and meta-analysis of 62 studies involving more than 46 million patients to determine the overall suicide mortality of patients with cancer. They found that these patients have a risk of dying by suicide nearly 2-fold greater than that of the general population, with a 3.5-fold greater suicide mortality seen in patients with cancers known to have a poor prognosis, including cancers of the liver, stomach and head.

The findings could help to inform collaborative cancer-psychiatric care initiatives by prioritizing patients who are most at risk and identifying early signs of suicidal intentions, and reducing short- and long-term risk of suicide.