The influence of urbanization, age, ethnicity, and income on the early diagnosis of breast carcinoma: Opportunity for screening improvement

Abstract

BACKGROUND. Because most risk factors for breast carcinoma are not readily amenable to primary prevention, and early diagnosis is a powerful prognostic determinant, screening for the disease is crucial. Consequently, assessment of the progress and comprehensiveness of screening and other breast carcinoma early detection activities is important. The relative frequency of early diagnosis may provide a useful indicator of such activities. Nationwide, time trends in the early diagnosis of breast carcinoma have been improving for decades, but not all population subgroups may have benefited equally. METHODS. Using 1994-1997 data from the California Cancer Registry (CCR), a review of diagnostic patterns of in situ and local stage breast carcinoma was undertaken. For analytic purposes, the CCR includes 10 regional registries and 36 county reporting groups. Three early diagnostic measures were designated, including in situ breast carcinoma with tumor size < 10 mm in greatest dimension, in situ breast carcinoma, and localized breast carcinoma with tumor size < 21 mm in greatest dimension. These are referred to hereinafter as early diagnosis breast carcinomas. RESULTS. The percentage of early diagnosis breast carcinomas differed markedly by age, ethnicity, diagnosis year, and county of residence. Lower percentages of early diagnosis breast carcinomas were diagnosed in older women age ≥ 85 years. Hispanic women were diagnosed with lower levels of in situ breast carcinoma. Hispanic and black women were diagnosed with less localized breast tumors of small size. There was an increase in the percentage of early diagnosis breast carcinomas over the 4-year observation period. Lower percentages of early diagnosis breast carcinomas were reported for the nonurban county/county groups, which were characterized by greater distances, lower population density, and lower household incomes. CONCLUSIONS. The authors conclude that elderly women, Hispanic and black women, and women who reside in nonurban areas should be targeted as high-priority subpopulations for mammographic screening. © 2001 American Cancer Society.