Abstract
An immunocytochemical assay of estrogen receptor (ER-ICA) was performed to determine ER status of cytological materials obtained from primary breast cancer tumors in 18 cases by preoperative fine needle aspiration biopsy (FNAB). The results were compared with those of histological materials from surgical specimens to evaluate the value of this assay. In 8 cases with positive regional lymph nodes the same procedure was applied in the involved nodes of surgical specimens. The ratio of positive staining cells number/counted tumor cell number (PSR) was used for evaluation of ER-ICA. Over 10% of PSR was regarded as ER positive. The qualitative result of cytolotgical ER-ICA was compatible in 16 of the 18 (88.9%, p<0.0025) with that of histological ER-ICA in primary tumors. Moreover, PSR in cytological materials significantly correlated with that in histological materials (r=0.907). In the involved nodes, FNAB was useful for determing the ER status as well as in primary tumors except some cases obtained no or few malignant cells by FNAB. In conclusion, ER-ICA in FNAB was a new useful technique for evaluation of ER status in small primary tumors, inoperable breast cancer tumors, and local recurrences.
