Suicide risk significantly increases within the first year of a cancer diagnosis, with risk varying by type of cancer, according to investigators who conducted a retrospective analysis representing nearly 4.7 million patients.
Risk of suicide in that first year after diagnosis was especially high in pancreatic and lung cancers, while by contrast, breast and prostate cancer did not increase suicide risk, reported the researchers, led by Hesham Hamoda, MD, MPH, of Boston Children’s Hospital/Harvard Medical School, and Ahmad Alfaar, MBBCh, MSc, of Charité–Universitätsmedizin Berlin.
That variation in suicide risk by cancer type suggests that prognosis and 5-year relative survival play a role in increasing suicide rates, according to Dr. Hamoda, Dr. Alfaar, and their coauthors.
“After the diagnosis, it is important that health care providers be vigilant in screening for suicide and ensuring that patients have access to social and emotional support,” they wrote in a report published in Cancer. Their analysis was based on 4,671,989 patients with a diagnosis of cancer in the Surveillance, Epidemiology, and End Results (SEER) database between 2000 and 2014. Out of 1,005,825 of those patients who died within the first year of diagnosis, the cause of death was suicide for 1,585, or 0.16%.
Overall, the risk of suicide increased significantly among cancer patients versus the general population, with an observed-to-expected (O/E) ratio of 2.51 per 10,000 person-years, the investigators found. The risk was highest in the first 6 months, with an O/E mortality of 3.13 versus 1.8 in the latter 6 months.
The highest ratios were seen for pancreatic cancer, with an O/E ratio of 8.01, and lung cancer, with a ratio of 6.05, the researchers found in further analysis.
Significant increases in suicide risk were also seen for colorectal cancer (2.08) and melanoma (1.45), though rates were not significantly different versus the general population for breast (1.23) and prostate (0.99), according to the reported data.
Suicide risk was relatively high for any cancer with distant metastases (5.63), though still significantly higher at 1.65 in persons with localized/regional disease, the data show.
The increased suicide risk persisted more than 1 year after the cancer diagnosis, though not to the degree observed within that first year, they added.
Most patients with suicide as a cause of death were white (90.2%) and male (87%). Nearly 60% were between the ages of 65 and 84 at the time of suicide.
Social support plays an integral role in suicide prevention among cancer patients, the researchers noted.
Previous studies suggest that support programs may decrease suicide risk by making patients better aware of their prognosis, receptive to decreased social stigma, or less likely to have stress related to cost of care, they said.
“Discussing the quality of life after diagnosis, the effectiveness of therapy, and the prognosis of the disease and maintaining a trusting relationship with health care professionals all decrease the likelihood of suicide immediately after a diagnosis of cancer,” they said.
Dr. Hamoda, Dr. Alfaar, and their coauthors reported no conflicts of interest. Funding for the study came in part from the German Academic Exchange Service (Dr. Alfaar).
SOURCE: Saad AM, et al. Cancer 2019 Jan 7. doi: 10.1002/cncr.31876.