PREVALENCE OF ANEUPLOIDY, OVEREXPRESSED ER, AND OVEREXPRESSED EGFR INRANDOM BREAST ASPIRATES OF WOMEN AT HIGH AND LOW-RISK FOR BREAST-CANCER

Breast tissue biomarkers which accurately predict breast cancer develo pment within a 10 year period in high risk women are needed but curren tly not available. We initiated this study to determine 1) the prevale nce of one or more breast tissue abnormalities in a group of women at high risk for breast cancer, and 2) if the prevalence of biomarker abn ormalities is greater in high risk than in low risk women. Eligible hi gh risk women were those with a first degree relative with breast canc er, prior breast cancer, or precancerous mastopathy. Low risk women we re those without these or other major identifiable risk factors. Ducta l cells were obtained via random fine needle aspirations and cytologic ally classified. Biomarkers included DNA ploidy, estrogen receptor (ER ), and epidermal growth factor receptor (EGFR). The prevalence of DNA aneuploidy was 30%, overexpression of ER 10%, and overexpression of EG FR 35%, in the 206 high risk women whose median 10 year Gall risk (pro jected probability) of developing breast cancer was 4.5%. The prevalen ce of aneuploidy and overexpressed EGFR was significantly higher in th e high risk women than in the 25 low risk controls (p < 0.002), whose median 10 year Call risk was 0.7%. The difference in the prevalence of ER overexpression between high and low risk groups was not statistica lly significant (p = 0.095). This may be due to the low prevalence of overexpressed ER and the small number of controls. A significant diffe rence was noted in the prevalence of one: or more abnormal biomarkers between the high risk and low risk women (p < 0.001). A large prospect ive trial is needed to determine if one or more of these biomarkers, i s predictive of breast cancer development.