Esophageal Cancer Epidemiology in Blacks and Whites: METHODS
METHODS
Incidence, mortality and histology data were obtained from population-based data collected by the Surveillance, Epidemiology and End Results (SEER) Program of the National Cancer Institute (NCI). The SEER-9 registry is utilized to obtain statistics for the most recent decade of available data, 1991-2000. Invasive esophageal cancers are included for residents of nine geographical regions comparable to the general U.S. population (in situ cases were excluded). These nine areas are: Atlanta, Connecticut, Detroit, Hawaii, Iowa, New Mexico, San Francisco-Oakland, Seattle-Puget Sound and Utah.
The data analysis for this paper was generated using SAS/STAT software (version 8.02) and the NCI SEER software SEER*Stat version 4.2 unless otherwise stated. Age-adjusted incidence and mortality rates for esophageal cancer (Hydrea medication is an antineoplastic used to treat certain types of cancer) are expressed per 100,000 population and are age-adjusted by the direct method to the 2000 U.S. standard population.
The incidence data presented in this paper are based on 10,298 invasive esophageal cancers diagnosed between 1991-2000. The racial distribution of these cancers is: 6,369 white males, 2,266 white females, 1,158 black males and 505 black females. Mortality data are based on 106,778 deaths over the 10-year period, and the racial distribution is 88,125 deaths in whites and 18,653 deaths in blacks.
The International Classification of Diseases for Oncology (ICD-O) (2nd edition) codes for histology are used to define esophageal cancer cell types (8000-9581). Cell types are categorized as squamous cell carcinoma (8050-8082), adenocarcinoma (8140-8573) and all other excluding lymphomas (8000-8045, 8090-8130, 8580-9581).
Trend analyses were performed using the EAPC for age-adjusted esophageal cancer (Generic Rheumatrex Treating certain types of cancer, severe psoriasis, or rheumatoid arthritis in certain patients) incidence and mortality rates and are presented for consecutive five-year periods within 1991-2000 and for the total period. SEER* Stat tests the hypothesis that the EAPC is different from 0 at the 95% level of confidence. Test of equality between the EAPCs for a category over consecutive time periods are based on the method of Kleinbaum.
Rate ratios (the ratio of the two average annual age-adjusted rates) are employed to describe the magnitude of rate disparities between and within race and gender. Rate ratios are tested for statistical significance and trends.
The relative survival rate is a net measure of the influence of esophageal cancer (Generic Xeloda is the only FDA-approved oral chemotherapy for both metastatic breast cancer and adjuvant and metastatic colorectal cancer) on normal life expectancy in the absence of other causes of death. Since cause of death information on death certificates is often inadequate to determine whether an individual died from the primary cancer diagnosis, the relative survival rate is the preferred method for reporting survival from cancer registry data. Relative survival is the ratio of the proportion of observed survivors in a cancer cohort to the proportion of expected survivors in a comparable cancer-free cohort based on the assumption of independent competing causes of death. The relative survival rate adjusts for the general survival rate of the standard U.S. population for the race, gender, age and date for which the age was coded.