Suicide Risk Rises for Cancer Patients, Especially Advanced Stage

OTTAWA, Ontario, Oct. 19 -- Cancer patients in the U.S. are more than twice as likely to commit suicide as the general population, with the rate for men nearly five times that for women.

The composite picture for suicide risk was that of a white man, with a new diagnosis of either head-and-neck cancer or myeloma, widowed, with widely disseminated and perhaps high-grade disease, limited treatment options, or maybe a history of other cancers.

So revealed an analysis of 1.3 million U.S. cancer cases diagnosed from 1973 to 2001 and recorded in the Surveillance, Epidemiology, and End Results (SEER) registry, Wayne Kendal, M.D., of the Ottawa Hospital Regional Cancer Center here. reported online in the Oct. 19 issue of Annals of Oncology.

The analysis found that 19 of every 1,000 male cancer patients and four of every 1,000 female patients took their own lives.

This amounted to 265 women and 1,307 men, reflecting 0.04% for women and 0.19% for men, he said. The overall hazard ratio (HR) for male suicide was 6.2 (95% confidence interval 5.4-7.1).

At around 24 suicides per 100,000 cancer patients a year, the rate was two to 2.5 times that of the general American population (10.6 per 100,000 per year, including the cancer population), This almost fivefold greater rate for men parallels the male-female ratio for suicide in the general population, Dr. Kendal added.

However, the smaller number of women in this cohort and the resulting lower statistical power could account for the findings, Dr. Kendal said. It is also possible that women, as in the general population, were less likely to react with self-directed violence.

The risk of suicide varied according to gender, prognosis, disease stage, type of cancer, ethnicity, and family status, Dr. Kendal said. Of all the risks, not surprisingly, advanced-stage cancer was a major suicide risk factor, with a higher risk for men even with intermediate-stage disease, Dr. Kendal added.

Analyzed according to sex, the women fared better. The suicide rates were similar for most cancer sites, except for colorectal (P = 0.01) and cervical cancer (P< 0.0001), which were lower. The suicide risk for breast cancer in women was similar to that in the overall female cancer population, according to the findings.

Among men, the highest suicide rates were for head-and-neck cancers (P < 0.0001) and myeloma (P = 0.02), whereas men's rates were lower for lung cancer (P = 0.01), liver cancer (P = 0.01), brain tumors (P = 0.04), and leukemia (P = 0.007).

In a further comment on the suicide risk for head-and-neck cancers, Dr. Kendal wrote that these cancers provided the highest risk of suicide at any site, Of the available data, male gender remained the dominant risk factor. The suicide risk with these cancers increased with age but decreased with married status.

The hazard ratio associated for male suicide with distant metastasis was high (HR 2.84, 95% CI 2.49-3.24). Married status was protective (HR 0.46, CI 0.39-0.54) as was African-American ancestry, (HR 0.24, CI 0.17-0.34). Ratios were comparable for female suicides.

African-Americans' lower risk was consistent with religious and cultural beliefs, and perhaps family support, Dr. Kendal said.

In head-and-neck cancers, with both genders analyzed together, the suicide hazard was increased if surgery was contraindicated (HR 3.0, CI 1.3-6.8), but not if it was simply refused.

These results for men with head-and-neck cancers, especially cancer of the oropharynx (HR 3.0 (CI 1.4-6.2), point to quality of life issues, such as coping, symptom control, psychological stress, and difficulty eating. As for myeloma, chronic pain, weakened bones, and fractures might play a major role in prompting suicide.

Although advanced cancer was one of the stronger risk factors for suicide in this analysis, surprisingly, pancreatic cancer, with its well-known poor prognosis, did not have a risk higher than that of other cancers, Dr. Kendal reported. Similarly, refusal of either surgical treatment or radiotherapy did not figure as significant risk factors in the present analysis.

However, for all the cancers, not just head-and-neck malignancies, there was a significant likelihood of suicide when surgery was contraindicated, probably indicating advanced disease or other comorbidites.

On the positive side, the data confirmed that compared with single status, current married status lowered the risk of suicide (HR 0.46, CI, 0.39-0.54), although the benefit was more for men than for women. Being widowed, divorced, or separated did not help, suggesting that depression played a role in many of the suicides in this study.

Using the SEER data, Dr. Kendal said, it was not possible to differentiate between suicides associated with affective illness or substance abuse and those motivated by a desire for relief from terminal illness or the avoidance of being a burden to others.

This high-risk picture, he said, might be associated with substance abuse, poor quality of life, or psychological issues in the context of poor family and cultural support, as well as a poor cancer prognosis, he added.

In contrast, for decreased risk, one might envision a woman of African-American heritage, with colorectal or cervical cancer, localized disease, and living with her spouse.

In the general population, mental illness and substance abuse figure prominently as high risk factors, noted Dr. Kendal. However, in this study, it was not possible to differentiate, on the basis of the SEER data, between suicides associated with affective illness or substance abuse and those motivated by the desire for relief from terminal illness or the avoidance of being a burden to others.

To help people cope with their cancer, Dr. Kendal concluded, oncologists and allied health-care workers should be alert to the risk of suicide in cancer patients, particularly those with high-risk factors such as poor social support, substance abuse, and a history of mental health problems.