The incidence of suicide among U.S. cancer patients is nearly twice that of the general population, and suicide rates vary among patients with cancers of different anatomic sites, according to a study published online August 11 in the Journal of Clinical Oncology (JCO). The risk remained elevated for as long as 15 years after diagnosis.

Researchers from the University of Washington analyzed Surveillance, Epidemiology, and End Results (SEER) data from nearly 3.6 million patients diagnosed with cancer from 1973 to 2002. They compared those data, which included 5,838 suicides, with data from the U.S. general population collected by the National Center for Health Statistics. The cancer patients had an adjusted rate of 31.4 suicides per 100,000 person-years, compared with 16.7 suicides in the general population. Suicide rates were particularly high for cancers of the lung/bronchus (81.7), stomach (71.7), oral cavity/pharynx (53.1), and larynx (46.8).

Two other studies that examined the association between cancer and suicide appear in the same issue of JCO. The second study, using data from Medicare patients in New Jersey, found that the "risk of suicide in older adults is higher among patients with cancer than among patients with other medical illnesses, even after psychiatric illness and the risk of dying within a year were accounted for." A third study of cancer center patients in Edinburgh, United Kingdom, found, "A substantial number of cancer outpatients report thoughts that they would be better off dead or had thoughts of hurting themselves."

In an editorial, Dr. Timothy Quill of the University of Rochester Medical Center, noted, "What is interesting and potentially important about the studies is that these thoughts about suicide and the associated risk factors that are relatively well known for terminally ill patients may be just as important for those patients with cancer who are survivors or are living with the disease."