MEMORANDUM FOR: Science Writers and Editors on the Journal Press List

Accuracy of Death Certificates of Prostate Cancer Patients Questioned

April 13, 2000 (EMBARGOED FOR RELEASE 4 P.M. EST April 18)

Katherine Arnold, Deputy News Editor, Dan Eckstein, (301) 986-1891, ext. 112

Assignment of cause of death can be subjective. A new study suggests that assignment of cause of death in men with prostate cancer may depend on the treatment given.

A study in the April 19 issue of the Journal of the National Cancer Institute found that, among prostate cancer patients, cause of death was attributed to cancers other than prostate cancer more often in men who received aggressive treatment compared with men who were treated with watchful waiting.

Prostate cancer tends to affect older men and to progress slowly. Since the prevalence of other diseases increases with advancing age, other causes of death contribute to the death rate among prostate cancer patients. Accurate determination of the true causes of death in older men dying with prostate cancer may thus be difficult.

Craig J. Newschaffer, Ph.D., Department of Epidemiology, Johns Hopkins School of Hygiene and Public Health, Baltimore, Md., and Department of Community Health, Saint Louis University School of Public Health, St. Louis, Mo., and colleagues addressed this question by studying two groups. The first consisted of 1,207 men aged 67 years or older who had lived in Virginia and were diagnosed with prostate cancer from 1987 through 1989. The second group consisted of 2,906 men aged 67 years or older who were hospitalized in Virginia from 1987 through 1989 with benign prostatic hyperplasia (an enlarged but noncancerous prostate) who died of various causes.

Causes of death were categorized as prostate cancer, heart disease, other cancer, cerebrovascular disease, chronic obstructive pulmonary disease (COPD), pneumonia, diabetes, nephritis, septicemia, Alzheimer’s disease, hypertension, and other. The specific conditions used, other than prostate cancer, are the 10 most common underlying causes of death in white and African-American men over age 65 years in 1995.

Prostate cancer was the cause of death for 39% of the men in the prostate cancer group. Causes of death among prostate cancer patients not dying of prostate cancer were similar to those among the nonprostate cancer cohort. However, in those prostate cancer patients not dying of prostate cancer who were aggressively treated, the adjusted odds of other cancer causes of death were 51% higher than that in nonprostate cancer patients, while in those treated with watchful waiting the adjusted odds were 34% lower.

The authors suggest that one possible explanation for this may be information bias—that assignment of the cause of death could be dependent on knowledge of the treatment given. For example, they suggest that people completing death certificates for prostate cancer patients known to have received aggressive treatment may have been less likely to list prostate cancer as the cause of death because of their beliefs regarding the effectiveness of aggressive treatment.

In an editorial, Peter Albertsen, M.D., University of Connecticut Health Center, Farmington, notes that information on death certificates needs to be validated against primary medical records. If a systematic reporting bias exists, especially one associated with initial treatment of prostate cancer, Albertsen points out that such bias would have a major impact on our ability to determine whether early detection and treatment lead to decreased prostate cancer mortality. Accurate determination of the nature and magnitude of such systematic biases will be crucial to appropriate interpretation of population trends. Albertsen concludes that Newschaffer et al. raise important issues that need to be pursued by the research community.

Contact: Kathy Moore, Johns Hopkins School of Public Health (410) 955-6878; fax (410) 955-4775. Editorial: Jane Shaskan (860) 679-4777; fax (860) 679-1323.

Note: This memo to reporters is from the Journal staff and is not an official release of the National Cancer Institute (NCI) or Oxford University Press (OUP) nor does it reflect NCI or OUP policy. In addition, unless otherwise stated, all articles and items published in the Journal reflect the individual views of the authors and not necessarily the official points of view held by NCI, any other component of the U.S. government, OUP, or the organizations with which the authors are affiliated. Neither NCI nor any other component of the U.S. government nor OUP assumes any responsibility for the completeness of the articles or other items or the accuracy of the conclusions reached therein.



             
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