Abstract 5572: Auto-analysis of immunohistochemical findings and one-day instant quality fluorescence in situ hybridization increase quality of breast cancer therapy

Abstract

Abstract Background:Currently, the therapeutic strategy for a breast cancer patient is designed according to his/her histopathological, immunohistochemical and molecular findings. These findings are obtained through the collected efforts of many individual pathologists or medical technologists and are thus limited by intra-observer error and potentially subjective decision-making. The assessment of immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) is demanded to be prompt, objective, and reproducible. In our institute, the authors are utilizing the whole slide imaging system (NanoZoomer 2.0-HT, Hamamatsu photonics, Japan) and a software for image analysis (Genie, Vista, CA), specifically for an auto-analysis of IHC. We succeeded in gaining objective and highly reproducible results. On the other hand, current FISH technique is time-consuming and takes two days to complete due to the overnight incubation required to obtain proper hybridization result. The authors tried to compare the results with current FISH (cFISH) and one-day Instant Quality FISH (IQFISH) for human epidermal growth factor receptor 2 (HER2). Methods: Auto-analysis arm. Twenty-five breast cancer specimens were examined for IHC of estrogen receptor (ER), progesterone receptor (PgR) HER2, Topoisomerase (Topo) II alpha, and Ki-67, and the results were compared by ocular observation and auto-analysis. Fifty-one cancer specimens were compared in terms of IHC and cFISH of HER2.IQFISH arm. Thirty-four biopsy samples from pre-therapeutic breast cancers (29 primary invasive ductal carcinomas and five metastatic cancers) were examined and the results of cFISH and IQFISH were compared. Results: Auto-analysis arm. For all antibodies, expect for HER2, concordant results were obtained in 100% of 24 ER positive cases. Ki-67 index (r=0.96) and TopoIIalpha index (r=0.95) also showed a significant correlation (p<0.001). For cHER2, all four specimens with Hercep-score 2 by ocular observation but 1 by auto-analysis revealed no HER2 gene amplification. IQFISH arm. IQFISH (r=0.66) showed a significant correlation (p<0.0001) with cFISH. Both auto-analysis and IQFISH reduced substantially the time for analysis. Conclusion: Well-organized auto-analysis is more likely to result in an objective observation and provide a means by which to standardize the methods of IHC in breast cancer. IQFISH may contribute to an earlier decision regarding therapeutic strategy for a breast cancer. Citation Format: Daiki Taniyama. Auto-analysis of immunohistochemical findings and one-day instant quality fluorescence in situ hybridization increase quality of breast cancer therapy. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5572. doi:10.1158/1538-7445.AM2014-5572