Maps have long been used in surveillance of disease and in epidemiologic investigations. New technology using global positioning systems (GPS) coupled with geographic information systems (GIS)has revolutionized the field of geographic surveillance. Investigators associated with the SEER registries have started to use this technology to enhance cancer surveillance, fill gaps in surveillance coverage, find new cases of cancer, and reduce cancer mortality.
In 2003, a New Jersey state report summarized the analytic results confirming a statistically significant increase in childhood cancers for the period 1979 to 1995 in Dover Township. This increase was due primarily to excess leukemia, brain, and central nervous system cancers in females less than 5 years old. A case-control analysis revealed increased association for leukemia in young girls and high exposure to well water in proximity to a Superfund industrial site. An elevated association between leukemia and postnatal exposure to private well groundwater for both males and females was observed. Prenatal exposure to ambient air pollution was associated with leukemia among girls aged 0 to 4 years.
A second investigation examined access to mammography clinics among recently diagnosed breast cancer cases in New Jersey using spatial statistics in conjunction with a GIS analysis. Geographic analysis based on place of residence identified two areas in northeastern New Jersey with significantly high proportions of women with distant stage breast cancer. The women who had a later stage of breast cancer at diagnosis in these two areas differed from other late stage cases in the rest of the state; they were older (65+), more likely to be a minority, were less educated, less likely to be employed, and were more likely to be isolated linguistically (primary spoken language not English). Some of these women lived only a short distance from a mammography facility. The New Jersey registry/ department of health is using these results to more effectively target populations for cancer screening with the goal of reducing mortality from breast cancer.
Blumenstock J, Fagliano J, Bresnitz E. The Dover Township childhood cancer investigation. New Jersey Med 2000; 97:25-30.
Roche LM, Skinner R, Weinstein RB. Use of a geographic information system to identify and characterize areas with high proportions of distant stage breast cancer. J Public Health Manag Pract 2002;8:26-32.
New Jersey Department of Health and Senior Services Case-control Study of Childhood Cancers in Dover Township (Ocean County), New Jersey. Volume I: Summary of the Final Technical Report. January 2003. http://www.state.nj.us/health/eoh/hhazweb/dovertwp.htm. Accessed July 24, 2003.