in medical records or death certificates, whereas the U.S. Census uses self-designation of race or ethnicity. Surname lists were used to improve the identification of several groups (Hispanic, Chinese, Filipino, Japanese and Korean patients with cancer). These sources of error, however, indicate that "the cancer rates are best used to identify general racial/ethnic patterns of cancer" (Miller et al., 1996, p. 8).

The SEER program registry reports on three important pieces of information for selected populations: (1) the occurrence of cancer (incidence); (2) rate of death from cancer (mortality), as reported by the National Center for Health Statistics (NCHS); and (3) the length of survival following cancer diagnosis (survival rate). Incidence measures the frequency of cancer in a group or population. Decreases in cancer incidence can indicate successful efforts in the prevention of cancer. For example, the incidence of cervical cancer has decreased in the United States since the advent of the Pap smear in the 1940s, which detects cervical lesions for treatment before they become cancerous. Conversely, an increase in the prevalence of smoking among women has been reflected in increasing rates of lung cancer in this group. Typically, as in the case of lung cancer among women, increased incidences of cancer precede an increase in mortality (Extramural Committee to Assess Measures of Progress Against Cancer, 1990).

Mortality rates remain the most important measure of the overall