Methodological Issues - Geographic Information Systems
Geographic Information Systems (GIS) identify and display geographic
patterns, which are particularly useful in examining cancer screening,
incidence, and mortality rates in the U.S. Additionally, these methods
can be used to investigate any number of geospatially-related questions.
For example, researchers can use GIS to investigate the distances
between patients and screening or treatment facilities so as to
determine why individuals in certain geographic regions have different
rates of screening or therapies. Changes over time can also be investigated.
GIS systems can aid in the communication of information to the public
and public health professionals. The goal of GIS research is to
improve the methodology and adapt it to the monitoring, detecting,
and communicating trends.
Additional information on GIS can be found at: http://gis.cancer.gov/
RRSS investigators are conducting studies to:
- develop population estimates on a very small
grid to compute and compare different geographic measures of cancer;
- develop and apply new methods for smoothing temporal-spatial
trends in cancer incidence;
- determine the usefulness and feasibility of using GIS for reporting
cancer incidence on the Internet;
- evaluate GIS capabilities and test various ways in which geographically
based cancer incidence reporting systems can be used;
- assess the accuracy of geocoding of cancer registry data;
- evaluate the use of state motor vehicle records to improve the
accuracy of geocoding patients' addresses at time of diagnosis
- use GIS technology to investigate the relationship of non-melanoma
skin cancer to area-based indirect measures of UVB radiation in
Registries Funded to Conduct these Studies
Researchers geocoded the addresses of non-melanoma skin cancer
patients and calculated an ambient UVB measure for each town or
city. The UVB measure and the rate of non-melanoma skin cancer were
The presentation of registry data in a GIS over the Internet was
determined to be feasible and because the data would be presented
in summary form, confidentiality problems would be unlikely.
The use of GIS continues to gain popularity. Data that take advantage of geocoding are increasingly being made
available on the SEER website. Additional research continues into the best
methods for graphically presenting GIS data.