Objective: The assessment of spatial and temporal trends in breast carcinoma incidence can signal changes in ascertainment, changes in risk, and possibly point to changes in underlying risk factors. It is important to develop geographic maps to identify hot spots where cancer rates, by race and by histologic type, are elevated to better appreciate changes in cancer risk.

Methods: Incidence data for breast carcinoma, 1985–2004, was requested from the Pennsylvania Cancer Registry (PCR). Joinpoint regression model was applied to characterize age‐, race‐ and histologic type‐specific breast tumor incidence time trends in Pennsylvania (PA). Geographic Information System methods and spatial analysis is also being applied to these data to detect spatial clusters of diagnosed breast carcinoma in PA.

Results: Among whites, age‐adjusted incidence for ductal carcinoma in situ (DCIS) increased significantly from 1985 to 1999 and incidence for lobular carcinoma in situ (LCIS) slightly increased from 1994 to 2004, although this increase was not significant. Among blacks, age‐adjusted incidence for DCIS and LCIS increased significantly over the entire study period. Age‐adjusted incidence for malignant breast carcinoma slightly decreased from 1997–2004 among blacks but more recently since 2001 has shown a sharp decrease among whites (annual percent change = −3.0). Between 1985 to 2004, for women under age of 40, age‐adjusted incidence of breast carcinoma in situ (DCIS, LCIS, mixed) significantly increased 4.5% and 10.0% annually for whites and blacks, respectively. Incidence for malignant breast carcinoma slightly decreased over the study period.

To better define invasive breast cancer risk in PA, spatial clustering analysis performed to identify county‐specific changes in malignant breast carcinoma incidence. This analysis showed significant spatial clustering in Pennsylvania (P=0.024) and the region of increased invasive breast cancer was clustered in seven southeastern counties.

Conclusion: Incidence for breast carcinoma in situ increased significantly among women in PA. An increase in invasive breast cancer was identified in seven southeastern counties. Factors responsible for the state‐wide increase in breast carcinoma in situ and the elevated invasive breast cancer incidence in southeastern Pennsylvania should be carefully assessed.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):A130.

Copyright © January 7, 2010, American Association for Cancer Research
2010