Does a Cancer Diagnosis Increase Suicide Risk?

December 6, 2018

Researchers in England investigated whether risk for suicide was elevated in cancer patients, and which cancer types might have the greatest risk.

The results of a population-based study in England reported an increase in suicide risk in individuals who had been recently diagnosed with cancer. Compared with the general population, researchers noted a 20% increase in suicide risk in cancer patients.

The researchers, led by Katherine E. Henson, MSc, DPhil, of the National Cancer Registration and Analysis Service in London, noted that “a diagnosis of cancer carries a substantial risk of psychological distress,” and there may be “an unmet need for psychological support.”

Dianne Shumay, PhD, a psychologist at the University of California San Francisco, who was not involved with this research, told Cancer Network, "The news 'you have cancer,' is universally shocking and distressing to hear as a patient. ... Thoughts of suicide are very common, even for people who don’t intend to take any action to harm themselves. The function of these thoughts may serve as a way of having control when nothing else feels controllable."

The study, published in JAMA Psychiatry, included 4,722,099 adult patients aged 18 to 99 years with death certification data from Henson’s organization. Of this population, 50.3% were men and 49.7% were women.

Suicide deaths accounted for 0.08% of all deaths during the follow-up period of up to 22 years, for a total of 2,491 patients. The overall standardized mortality ratio (SMR) for suicide was 1.20 (95% CI, 1.16–1.25), and the absolute excess risk (AER) per 10,000 person-years was 0.19 (95% CI, 0.15–0.23).

The highest risk for suicide was seen in those with mesothelioma (4.51-fold risk, corresponding to 4.20 extra deaths per 10,000 person-years), followed by pancreatic (3.89-fold), esophageal (2.65-fold), lung (2.57-fold), and stomach (2.20-fold) cancers. Interestingly, a lower suicide risk was seen in those with melanoma and prostate cancer.

"The reaction of patients when they are diagnosed with diseases that have a poor life expectancy or which have a more difficult and painful process of treatment may contribute to this difference in suicide risk. There are other factors at play as well, as some cancers and cancer treatments have neuropsychiatric sequelae, which can increase a patient’s risk of depression and other psychiatric symptoms because of the physiological characteristics of the disease or treatment," noted Shumay.

Although researchers found that the risk for suicide was present for the first 3 years after receiving a cancer diagnosis, they noted that the most critical period of time was within the first 6 months. They reported an 8.61-fold risk in patients with mesothelioma during this 6-month period, compared with the general population.

“One limitation of the study is that it was not possible, due to current data availability, to adjust for preexisting psychiatric disorders or other potential confounders, such as alcohol or drug misuse diagnostic information. However, it has been demonstrated in a study of national cancer registration data that suicide risk is not explained by preexisting psychiatric conditions,” wrote the researchers.

Addressing the underdiagnosis and undertreatment of depression and anxiety in cancer patients may help mitigate the risk for suicide, according to the researchers. Additional provider responses may include improving access to integrated psychological support for all cancer patients, addressing risk factors, and barring access to drugs that can lead to lethal overdoses.

"Often patients are not referred to psychology or psychiatry until later in their treatment, but these statistics reinforce the need for early intervention with patients from the time of diagnosis with cancer. International standards call for all patients to be screened for distress and depression at pivotal points in their care. Patients who have been diagnosed with the types of cancer that put them more at risk for suicide should be monitored closely," said Shumay.