Cancer Patients at High Risk for Psychiatric Disorders, Suicide

Cancer patients are at a particularly high risk of mental health disorders and suicide, two studies showed.

In the first study, researchers found that cancer patients have nearly twice the risk of suicide compared with the general population, and about a 3.5 times greater risk if their cancers are known to have a poor prognosis, reported Corinna Seliger, MD, of the University Hospital Heidelberg in Germany, and colleagues.

In a second study, Alvina Lai, PhD, and Wai Hoong Chang, both of University College London, showed that the high proportion of cancer patients with psychological disorders subsequently have a higher risk of self-harm and mortality, compared with other patients with cancer.

Both studies were published in Nature Medicine.

In a commentary accompanying the studies, Cristiane Decat Bergerot, PhD, of the Instituto Unity de Ensino e Pesquisa in Brasilia, Brazil, and Sumanta K. Pal, MD, of City of Hope Comprehensive Cancer Center in Duarte, California, highlighted the importance of implementing screening strategies and providing supportive care in order to recognize psychiatric disorders in cancer patients.

The FDA “has outlined core concepts for patient-reported outcomes, including the assessment of emotional well-being, which, given these studies, must remain a crucial component of surveys in both clinical care settings and clinical trial settings,” they noted. “The consistent routine collection of such data will provide insight into the emotional well-being of patients and will enable provision of effective screening and care.”

Suicide Risk

In their systemic review and meta analysis of 28 studies that included more than 22 million cancer patients, Seliger and colleagues showed an 85% increased suicide mortality rate among patients with cancer compared with the general population (SMR 1.85, 95% CI 1.55-2.20).

Unsurprisingly, patients who had a cancer known to have a good prognosis (5-year survival rates >90%, such as thyroid cancer, nonmetastatic melanoma and nonmelanoma skin cancer, prostate cancer, and testicular cancer) had the lowest suicide rates (SMR 1.50, 95% CI 1.12-2.00). Suicide mortality was highest (SMR 3.53, 95% CI 2.75-4.53) for cancers known to have a poor prognosis, including cancers of the liver and biliary system, stomach, head and neck, central nervous system, pancreas and esophagus, and mesothelioma.

Geographically, suicide mortality among patients with cancer was greater in the U.S. than in Europe, Asia, or Australia. Seliger and her colleagues suggested that possible reasons for the higher rate in the U.S. is its lack of universal healthcare, as well as cultural differences, such as easier access to firearms.

The researchers also noted that African Americans had a slightly lower suicide mortality rate than other ethnic groups. “Possible reasons for this observation are misclassification of suicides in African-Americans, strong religious beliefs, family bonds and communalism observed in African-Americans,” they wrote.

Men had a higher suicide risk than women, although those results did not reach statistical significance.

“Despite immense progress in cancer therapy and prognosis in the past decades, suicide remains an important cause of death in patients with cancer,” observed Seliger and her colleagues. “Access to professional medical care and follow-up should therefore represent an integral component of any cancer therapy.”

Self-Harm and Psychiatric Disorders

In the second study, Lai and Chang showed that the higher risk of self-harm and mortality appeared to be particularly high early on, with the risk of self-harm at its highest within 12 months of a mental health disorder diagnosis.

Furthermore, patients who harmed themselves were 6.8 times more likely to die of unnatural causes within 12 months compared with controls (HR 6.8, 95% CI 4.3-10.7). However, the risk of unnatural death after 12 months was less pronounced (HR 2.0, 95% CI 1.5-2.7).

When Lai and Chang analyzed suicides alone, they found that individuals who self-harm were about 25 times more likely to die of suicide (HR 25.7, 95% CI 10.0-66.2).

The study was based on data from health records of 459,542 patients with 26 different cancers who were diagnosed between 1998 and 2020 in the U.K.

Of the individuals in the study, 5,683 had self-harm incidents after cancer diagnosis, with highest rates among patients with brain tumors, followed by prostate cancer, Hodgkin lymphoma, testicular cancer, and melanoma.

Depression was the most common psychiatric disorder in cancer patients, followed by anxiety disorders. Patients with depression had the highest risk of self-harm, with the cumulative burden per 100 individuals the highest with testicular cancer (98.05), cervical cancer (78.74), and Hodgkin lymphoma (69.87), at age 60.

The risk of depression and self-harm was particularly high within 12 months of diagnosis, “suggesting that patients require higher vigilance during this initial critical period,” Lai and Chang observed.

The biggest risk factor for developing mental health conditions was combined treatment with chemotherapy, radiotherapy, and surgery. These individuals were more likely to develop depression (28.23 per 100 individuals), anxiety (19.66), schizophrenia (2.53), personality disorders (0.05), and bipolar disorders (1.94). The lowest burden of psychiatric disorders was observed in patients who received radiotherapy alone.

Among treatment groups, patients who received alkylating agents for chemotherapy had the highest burden of psychiatric disorders, while patients who received kinase inhibitor treatment had the lowest burden of psychiatric disorders.