Clinical significance of assessing Her2/neu expression in gastric cancer with dual tumor tissue paraffin blocks.

Abstract

One paraffin block is routinely used for human epidermal growth factor receptor 2 (Her2/neu) immunohistochemistry (IHC) assessment. Here, we investigated if picking 2 paraffin blocks for Her2/neu evaluation on 1 slide is an economical, efficient, and practical method, which may reduce false negativity of Her2/neu IHC assessment due to intratumoral heterogeneity. A total of 251 gastric cancer (GC) patients were divided into a cohort using 1 tumor tissue paraffin block (single-block group, n = 132) and a cohort using dual tumor tissue paraffin blocks (dual-block group, n = 119) when evaluating Her2/neu expression status by IHC. In dual-block group, we combined the results from 2 different paraffin blocks and used the higher one as the final score. The number of IHC 1+, 2+, and 3+ specimens in the single-block group was 31 (23.5%), 40 (30.3%), and 19 (14.4%), respectively. The combined final IHC score in the dual-block group of 1+, 2+, and 3+ was 26 (21.8%), 34 (28.6%), and 23 (19.3%), respectively. Inconsistent Her2/neu expression between blocks was found in 36 (30.3%) cases in the dual-block group. The pooled data in the single-block group and the dual-block group indicated that, when using dual blocks, the Her2/neu-positive (3+) rate of GC was higher compared to that in the single-block group. Our results implied that using dual paraffin blocks to assess Her2/neu expression of GC may help identify more patients with Her2/neu-positive GC who could benefit from targeted therapy, by reducing false-negative rate of Her2 status assessment. This is an efficient, economical, and practical method for Her2/neu evaluation of GC.

• Authors: Xiaowen Ge, Haixing Wang, Haiying Zeng, Xuejuan Jin, Akesu Sujie, Chen Xu, Yalan Liu, Jie Huang, Yuan Ji, Yunshan Tan, Tianshu Liu, Yingyong Hou, Jing Qin, Yihong Sun, Xinyu Qin
• Journal: Human pathology (Hum Pathol) Vol. 46 Issue 6 Pg. 850-7 (Jun 2015) ISSN: 1532-8392 [Electronic] United States
• PMID: 25863425 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2015 Elsevier Inc. All rights reserved.

Chemical References

• Biomarkers, Tumor
• Paraffin
• ERBB2 protein, human
• Receptor, ErbB-2

Topics

• Adult
• Aged
• Aged, 80 and over
• Biomarkers, Tumor (metabolism)
• Female
• Gene Amplification (physiology)
• Humans
• Immunohistochemistry
• Male
• Middle Aged
• Neoplasm Staging
• Paraffin
• Receptor, ErbB-2 (metabolism)
• Stomach Neoplasms (metabolism, pathology)
• Tissue Preservation