Assessment of hormonal receptors and Her-2/neu status in breast cancer using cell block: a case study

Abstract

Objective To report the expressions of estrogen receptor (ER), PR (progesterone receptor), and human epidermal growth factor receptor type 2 (Her-2/neu) in a breast cancer patient using cell block prepared from fine needle aspirate (FNA). Study design FNA was obtained from the subject and cytomorphological diagnosis of stage II ductal carcinoma done on hematoxylin and eosin stain. This was followed with preparation of cell blocks from a portion of the aspirate and subsequent immunocytochemical technique, using heat-induced epitope retrieval (HIER). Specific monoclonal antibodies were used to determine the expressions of ER, PR, and Her-2/neu receptors. Positive and negative controls were included in the procedure at the same time the tests were done for the receptor assessments. For each receptor assessed, cells were counted from ten representative high-power fields and an average of cells that stained positive for respective markers, out of the total number of cells observed, was calculated. The data was produced in triplicate by three independent pathologists, from which more than 95% concordance was obtained. Results In this reported case, the steroid receptors were scored as: ER-positive (ER+) and PR-positive (PR+). Her-2/neu was positive (3+), implying a strong complete membrane staining in more than 10% of the tumor cells. Conclusion The successful use of FNA and immunocytochemistry (ICC) following HIER for the assessment of hormonal and Her-2/neu receptor status in breast cancer is here reported to have been done for the first time in our setting. The results must, however, be interpreted with caution using the counted cells captured in representative high-power fields assessed