Should cause of death from the death certificate be used to examine cancer-specific survival? A study of patients with distant stage disease.

Death certificates are used to classify cause of death for studies of cancer survival and mortality. Using data from the National Cancer Institute's Surveillance, Epidemiology, and End Results program, we evaluated cause of death (site-specific, cancer cause-specific, or other cause of death) for 229,181 patients with distant stage disease during 1994-2003 who died by 2005. Agreement between coded cause of death and initial diagnosis was 85% in patients with only one primary and 64% in patients with more than one primary. Our findings support the usefulness of site and cancer cause-specific causes of death reported on the death certificate for distant stage patients with a single cancer.