DETERMINANTS OF BREAST-CANCER DETECTION AMONG WISCONSIN (UNITED-STATES) WOMEN, 1988-90

Early detection is advocated widely as the best method to reduce the h igh rate of breast cancer mortality in women. The purpose of this stud y was to describe the detection histories of women with breast cancer and to identify factors related to the method of detection. During the period 1988-90, 3,197 women with invasive breast cancer, identified t hrough the Wisconsin (United States) tumor registry, were interviewed The method of cancer detection (classified as self, screening mammogra phy, or clinical breast examination [CBE]) was analyzed using polychot omous logistic regression. Fifty-five percent (1,754/3,197) of the wom en found their own cancers, while 35 percent (1,122/3,197) were detect ed by screening mammography. Compared with self-detection, the likelih ood of non-localized disease was significantly lower for tumors detect ed by mammography (odds ratio [OR] = 0.3, 95 percent confidence interv al [CI] = 0.2-0.4) and CBE (OR = 0.6, CI = 0.4-0.7). The likelihood of cancer being detected by screening mammography increased with increas ing age, education, number of prior mammograms, family history, and bo dy mass index (weight/height(2)) (BMI). Women in the highest BMI quint ile were 2.3 times (CI = 1.7-3.0) more likely than women in the lowest BMI quintile to have their cancers diagnosed by mammography. This ass ociation most likely results from breast tumors being more difficult t o palpate in heavier women.