DO PROGNOSTIC MARKER STUDIES ON CORE NEEDLE-BIOPSY SPECIMENS OF BREAST-CARCINOMA ACCURATELY REFLECT THE MARKER STATUS OF THE TUMOR

Core needle biopsies (CNB) are often used for the diagnosis of breast lesions. In some breast cancer patients, e.g., those treated with preo perative chemotherapy, the CNB specimen might be the only pretreatment tissue sample available for studies of prognostic and predictive mark ers. Our purpose was to evaluate whether marker studies performed on C NB specimens accurately reflect the marker status of the tumor. Immuno staining for five commonly used prognostic and predictive markers was performed on both CNB and subsequent excision specimens from 56 consec utive patients who had a CNB with carcinoma followed by excision of th e tumor. None of the patients received radiotherapy or chemotherapy be tween the CNB and the excision. Paraffin sections of the CNB and excis ion specimens were immunostained for bcl-2, estrogen receptor (ER), c- erbB-2, and p53. These markers were scored as positive or negative. Mi crovessel density (MVD) was scored as a continuous variable on section s immunostained for Factor VIII-related antigen by calculating the ave rage number of microvessels in three 224x fields of highest tumor vasc ularity (''hot spots''). Immunostaining results for bcl-2, ER, c-erbB- 2, and p53 on the CNB and the corresponding excision specimens were 10 0% concordant. Although there was significant correlation between MVD on the CNB specimens and the corresponding excisions (r = 0.507, P = 0 .0002), the mean MVD on the CNB and corresponding excision specimens d iffered by more than 10% in 85.7% of cases, with differences ranging f rom 4.3 to 233.3%. MVD was higher in the CNB than in the excision spec imens in 30 (61.2%) of 49 cases. In conclusion, in all of the cases st udied, accurate results for the dichotomously scored markers bcl-2, ER , c-erbB-2, and p53 were obtained on CNB specimens. In contrast, in mo st cases, MVD, which was scored as a continuous variable, could not be reliably assessed on the CNB specimen.