CME Author: Zeena Nackerdien
Study Authors: Anas M. Saad, Mohamed M. Gad, et al.
Target Audience and Goal Statement: Oncologists, psychiatrists, psychologists, internists, family doctors
The goal was to assess the risk of suicide within the first year after a cancer diagnosis as compared with the incidence in the general population.
- How many cancer patients died by suicide within the first year after their diagnosis?
- Does the suicide risk increase significantly after a diagnosis of cancer in comparison with the general population?
- Does any observed increase vary by demographics or tumor characteristics?
Synopsis and Perspective:
Advances in cancer management have improved the quality of life and increased survival rates for many cancer patients. But having cancer takes a profound toll on mental health. In addition to the effects of pain and various cancer treatments, results from previous studies have shed light on what could be happening to patients on a psychological and social level.
Sadly, cancer and suicide remain, respectively, the second and 10th leading causes of death in the U.S. Patients with cancer may have a nearly twofold higher risk for suicide compared with the general population, especially for certain cancers.
Demographic and biological factors may influence the suicide rate among patients with cancer — e.g., sex, age, cancer site, time since the initial diagnosis, and particularly depression. In addition, a small study showed that higher rates of suicide were observed in white males during the first 5 years after a cancer diagnosis.
Few large-population studies have been conducted over the last decade to examine the incidence of suicidal deaths among patients diagnosed with cancer.
For the new investigation, Ahmad Samir Alfaar, MBBCh, MSc, of Charité-Universitätsmedizin Berlin in Germany, and colleagues used 2000-2014 data from 18 registries within the Surveillance, Epidemiology, and End Results (SEER; ~27.8% of the U.S. population) database to conduct a retrospective, observational cohort study of 4,671,989 patients with cancer. Sex, race, state, cancer site, tumor stage, age, and marital status at the time of diagnosis were examined for all eligible patients, and mortality data for the general U.S. population was collected by the National Center for Health Statistics from 1969 through 2015.
Observed/expected (O/E) ratios — i.e., changes in the risk for suicide within 1 year after a cancer diagnosis in comparison with the general U.S. population — served as the main outcome measures. “Observed” was defined as the number of people who died by suicide; and “expected” represented the number of people who died by suicide in a demographically similar population within the same time frame.
A total of 1,585 cancer patients were found to have died by suicide within 1 year of receiving a diagnosis, which was a rate approximately 2.5 times that expected in the general population, the authors noted. Most of the cancer patients who died by suicide had some of the following demographic attributes at the time of their diagnosis: older age (65-84 years; 58%), white (90.2%), and male (87%).
“The second month after the cancer diagnosis carried the highest increase in risk, with an O/E ratio of 4.81,” the researchers reported. Moreover, 520 of the 1,585 patients who died by suicide had metastatic disease. The elevated suicide risk within 1 year following a diagnosis of metastatic cancer was higher (O/E = 5.63) compared with the increase after a diagnosis of localized/regional disease (O/E = 1.65).
Pancreatic (O/E = 8.01), lung (O/E = 6.05), and colorectal cancer (O/E = 2.08) diagnoses were associated with the highest risks for subsequent suicides. The risk was not found to have increased significantly, following diagnoses for breast and prostate cancers.
Study limitations, the researchers said, included possible bias because of the retrospective nature of the analysis, underreporting of suicides, and lack of information about anxiety and depression as independent mediators of suicides.
Source Reference: Cancer, Jan. 7, 2019; DOI: https://doi.org/10.1002/cncr.31876
Study Highlights: Explanation of Findings
This was the largest study to date that assessed recent trends in suicide risk after a cancer diagnosis. Compared within the general population, the risk of suicide increased significantly within the first year after a diagnosis of cancer. A diagnosis of breast or prostate cancer was not associated with an increased suicide risk, but the risk rose specifically following a diagnosis of pancreatic, lung, or colorectal cancer.
The results largely confirmed prior evidence from the literature with respect to an elevated suicide risk among U.S., Western European, and Japanese populations in the first year after a cancer diagnosis. Although Swedish researchers did not see a substantial difference in suicide risk based on tumor sites, they did note an increased suicide rate within the first year after cancer diagnosis in both men and women.
Italian and Danish researchers corroborated the supposition that a cancer diagnosis was a risk factor for suicide in separate studies. The Italian team found that the suicide risk was highest within the first 6 months after a cancer diagnosis, while Danish investigators also found that a diagnosis of a metastatic tumor and a diagnosis in patients older than 50 were associated with a higher suicide risk. This risk was highest in the first year after the cancer diagnosis.
Suicide risks in the Danish patient cohort remained elevated versus the general population even more than 5 years after receiving the diagnosis. And in another study conducted by Japanese researchers, patients who were recently diagnosed with cancer also had a much higher risk of suicide in comparison with those without a cancer diagnosis.
While the effects of culture or religion on suicide risk remain unclear, educational level (which can affect an individual’s understanding of prognosis) and a diagnosis with a cancer known to have a worse prognosis, are among the known factors that have been shown to correlate with suicide risk in patients with cancer.
“If you look at some of the leading causes of death across different age groups within the entire population, you’ll find both [cancer and suicide] on the top 10 list,” co-senior author Hesham Hamoda, MD, MPH, of Boston Children’s Hospital of Harvard Medical School, told MedPage Today. “For many patients with cancer, their actual death is not going to be a result of cancer itself, but rather on the emotional implications of having that diagnosis and taking their own lives.”
“After the diagnosis, it is important that healthcare providers be vigilant in screening for suicide and ensuring that patients have access to social and emotional support,” the researchers wrote. Such a process may involve screening for depression, anxiety, and opioid use. Depression and anxiety in these individuals may be due to many reasons — for example, the disfigurement associated with head and neck cancers as well as breast cancers, and the demands of caring for ostomies in patients with colorectal cancer. Recent studies have shown a link to improvements in the quality of life of depressed patients with cancer who received treatment for the depression.
“Discussing the quality of life after the diagnosis, the effectiveness of therapy, and the prognosis of the disease and maintaining a trusting relationship with healthcare professionals all decrease the likelihood of suicide immediately after a diagnosis of cancer,” the authors concluded.
Robert Jasmer, MD Associate Clinical Professor of Medicine, University of California, San Francisco