Abstract
Background/Aims Early diagnosis of breast cancer is an important prognostic indicator and missed mammograms represent missed opportunities for earlier diagnosis. Geographical access to mammography services is an important factor in mammography screening. In rural regions, mammography access can be problematic and longer travel distance has been shown to adversely affect early breast cancer detection in rural populations, although results are mixed. Recent advances in geographic information systems (GIS) technology allows for more accurate determination of point distance and travel time via road networks. The goal of the present study was to utilize modern GIS technology to determine the association between geographic proximity to mammogram centers and stage of breast cancer at diagnosis.
Methods Female patients with an initial diagnosis of primary breast cancer at the Marshfield Clinic between January 1, 2002 and December 30, 2008 were identified electronically through the Marshfield Clinic/St. Joseph’s Hospital cancer registry. Patients were classified by stage of breast cancer and analyzed to determine whether a correlation existed between stage and distance to closest facility, distance to visited facility, and rural or urban address location. ESRI ArcGIS Desktop version 10.0, ArcInfo license, Business Analyst extension, and StreetMap Premium using data from TeleAtlas 2010 were used to geocode point features and the ArcGIS Geocoding toolbar, Review/Rematch Addresses tool was used to substantiate the results.
Results A total of 1,368 patients with breast cancer was analyzed. A trend of increased travel time to nearest facility with increasing stage at diagnosis was observed (P = 0.0643), where median travel time was 17.1 minutes for stage 0 breast cancer and 23.9 min for stage 4 breast cancer. Significantly fewer mammograms were performed in the winter months (November through February) and the difference was particularly striking for patients living 30 or more miles from a mammography center (P = 0.0448).
Conclusions Using modern GIS technology, we showed that travel time affects mammogram utilization and thus stage at breast cancer diagnosis in the Marshfield Clinic service area. In rural areas, travel time and seasonal road conditions may impact on decisions to undergo mammography screening.
