Purpose of the Registry

Population-based cancer registries are essential for assessing the extent of cancer burden in a specified geographic area. The District of Columbia Cancer Registry (DCCR) is a population-based cancer registry that collects incidence data on all cancer patients who reside in or who are diagnosed and/or treated for cancer in the District of Columbia. The goals of the DCCR are:

• to determine the incidence of cancer in the District of Columbia with respect to geographic, demographic, and social characteristics
• to monitor trends and patterns of cancer incidence over time
• to identify high risk populations
• to provide a database and serve as a resource in conducting epidemiologic studies
• to provide data to assist public health officials, hospital administrators, and physicians to effectively plan services, prioritize health resource allocations and develop and measure prevention and intervention strategies.

History and Funding of the Registry

DCCR was established in 1985 following the introduction of home-rule for the self-governance of the District of Columbia. Prior to that date, the DCCR since 1963 was known as the Metropolitan Washington Cancer Registry with the mandate to gather the occurrence of cancer in the Washington metropolitan area covering Baltimore, Washington and Northern Virginia. The operations of the registry are mandated by Federal Statute code §6.4123 as amended in the Preventive Health Services Amendment Act (DC Law 6-83 of 1985, and DC Law 8-157 of 1990). Additional funding has been awarded to DCCR from the Centers for Disease Control and Prevention (CDC) with a five-year federal grant aimed at enhancing the timely, complete, and accurate collection of cancer data, and for the computerization of data collection from reporting sources.

Collection of Data

Each District hospital, out-patient surgery center, and pathology laboratory is responsible for the complete ascertainment of all data on cancer diagnoses and treatments provided in its facility within six months of diagnosis. Sources for identifying eligible cases include:

• hospitals
• out-patient surgery centers
• private pathology laboratories
• free-standing radiation centers
• physicians whose cancer cases are not otherwise reported by the facilities listed above
• death certificate sources from State Center for Health Statistics (Vitals Statistics Office)
• out-of-state cancer registries reporting a District resident receiving care in non-District health-care facilities.

When a cancer case is reported from more than one source the information is consolidated into one record. Reported cases contain the following data:

• patient demographics (including geographic place of residence at time of cancer diagnosis)
• description of cancer (including date of diagnosis, primary site, metastatic sites, histology, extent of disease, etc)
• first course of treatment.

Primary site, behavior, grade, and histology are coded according to the "International Classification of Diseases for Oncology, 2nd Edition". Stage of disease variables are coded using "SEER’s Summary Staging Guide" and "AJCC Manual for Staging of Cancer, 4th Edition". All other variables are coded following the rules of the North American Association of Central Cancer Registries, the SEER program, and the American College of Surgeons.

Reportable Cases

All in-situ or malignant neoplasms are reportable to DCCR, except in-situ cancer of the cervix. The database includes all cases of carcinoma, sarcoma, melanoma, lymphoma, and leukemia, diagnosed by histology/cytology, radiology, laboratory testing, clinical observation, and autopsy.

Basal and squamous cell carcinomas of the skin are excluded except when occurring on a mucous membrane or if the AJCC stage group is II, III, or IV.

In conformance with guidelines provided by the North American Association of Central Cancer Registries, cervix in-situ cases, if reported to the DCCR, have been excluded from this publication.

Confidentiality of Data

The District of Columbia cancer reporting law ensures the protection of confidential data and restricts the release of identifying data. Persons with access to confidential data are required to sign a pledge of confidentiality and are subject to penalty if they, through negligence or willful misconduct, disclose confidential data.

Quality Assurance

To assure validity and reliability of the data presented in this report, DCCR has many mechanisms in place to check data for quality and completeness. We use EDITS software which have standard edits using algorithms that check the content of data fields against an encoded set of acceptable possible contents and flag the acceptability of coded data. Edits include field edits, inter-field edits, and inter-record edits. Edits check for unlikely sex/site, site/histology, or site/age combinations. In addition to computerized edits, each case is manually reviewed for errors.

Records are also routinely checked for duplicate entries. Duplicate case checking is performed both manually and electronically using various methodologies.

The District’s 1996 incidence data used for this report have been audited by the North American Association of Central Cancer Registries. NAACCR audits are performed on pre-determined sample of reporting facilities and cases in a state’s central cancer registry database for a given year. The procedure involves re-casefinding and re-abstracting studies on selected facilities and cases to determine the extent of completeness and accuracy of cancer data. In the NAACCR Audit of the District’s 1996 incidence data, all non-federal reporting hospitals were included in the sample of hospitals, and 10 percent of the reported cases were sampled for re-abstracting studies.

NAACCR 1991-1995 Incidence and SEER 1992-1996 Mortality Rankings:

The latest report on cancer incidence for North America (Cancer in North America 1991-1995, Volume One: Incidence) published by NAACCR presented incidence rates for 42 US states and 12 Canadian provinces. In this report, the incidence rates for the 42 states were ranked, and compared with the 1996 incidence rates for DC The District of Columbia was not one of the 42 states included in NAACCR report.

Unlike the NAACCR incidence report, the SEER mortality rankings of states were derived from the National Center for Health Statistics (NCHS) data which do contain the District’s mortality data for the 1992-1996 calendar years. In the comparison of the SEER average mortality for the period 1992-1996, there were several instances when the District was among the highest 5 or lowest 5 mortality states being compared with the 1996 estimates of DC produced by DCCR.