Assessment of multiple prognostic and/or predictive biomarkers in patients with breast cancer with good reliability and reproducibility using samples obtained by fine-needle aspiration (FNA) can be of significant clinical value.
The objective of this study was to determine the reliability of assessment of breast carcinoma markers, Ki-67 and HER-2/neu, on agarose cell blocks (CBs).
FNA samples were obtained from 29 female patients presenting with primary breast carcinoma. To prepare CBs (cytoblocks), cells were fixed in 10% neutral formalin for 6–12 h, embedded in 2% agarose gel, processed using standard laboratory protocol for biopsy tissue, and paraffin-embedded. The expression of Ki-67 and HER-2/neu was evaluated by immunohistochemistry (IHC) on cytoblocks and their corresponding formalin-fixed, paraffin-embedded histological resection specimens.
Tissue sections exhibited high Ki-67 expression in 27/29 (93.1%) invasive breast carcinoma cases, whereas 2/29 (6.9%) tumors revealed low Ki-67 immunoreactivity. MIB-1-stained CBs showed high Ki-67 expression in 24/29 (82.7%) breast carcinoma cases, whereas 5/29 (17.3%) tumors revealed low expression. MIB-1 IHC staining on agarose CBs showed 26/29 (89.6%) tumors correlation with tissue results. IHC analysis of HER-2/neu protein expression on tissue sections revealed that 23/29 (79.3%) breast carcinoma cases were negative for overexpression (score 0 or 1+) and 6/29 (20.7%) were positive for overexpression (3+). On agarose CBs, 21/29 (72.4%) invasive breast carcinoma tumors were negative (0 or 1+) for HER-2/neu overexpression, 2/29 (6.9%) showed equivocal IHC staining (2+), and 6/29 (20.7%) tumors were positive (3+). IHC staining for HER-2/neu on agarose CBs showed 93.1% correlation with tissue results.
In invasive breast carcinoma, Ki-67 and HER-2/neu (negative/positive) expression could be determined with good reliability on agar CBs prepared from FNA using standard IHC procedures.
Departments of aPathology
bBiostatistics and Cancer Epidemiology, National Cancer Institute, Cairo University, Cairo
cDepartmemt of Pathology, South Valley University, Qena, Egypt
Correspondence to Mervat M.F. El-Deftar, MD, Department of Pathology, National Cancer Institute, Cairo University, 1 Fom Al-Khalig Street, Cairo 111469, Egypt Tel: +20 100 691 5751; fax: +20 202 2364 4720; e-mail: email@example.com
Received July 2, 2017
Accepted August 8, 2017