Reproducibility of LSI HER-2/neu SpectrumOrange and CEP 17 SpectrumGreen Dual Color deoxyribonucleic acid probe kit. For enumeration of gene amplification in paraffin-embedded specimens: a multicenter clinical validation study

Overexpression and/or amplification of HER-2/neu gene have been found to be prognostic and predictive in breast and other cancers. Fluorescence in situ hybridization (FISH) assay, with its sensitivity and specificity, can be a superior method of detection when its performance characteristics are demonstrated. A multicenter study was initiated to evaluate the reproducibility of the LSI HER-2/neu SpectrumOrange and CEP 17 SpectrumGreen Dual Color DNA Probe for enumeration of both the HER-2/neu gene and chromosome 17 (signals) in interphase cells. Section slides were prepared from four cell lines (H, E, R, and N) with known ratios of the HER-2/neu to CEP 17 copy numbers (approximately H = 1.10, E = 1.70, R = 4.50, N = 9.0). The study variable was the ratios of the HER-2/neu to chromosome 17 copy numbers. Reproducibility with respect to assay, site, lot, day and reader was evaluated at 3 centers. Out of 120 specimen slides, 100 percent were successfully assayed. There were no significant differences among: (1) four repeated assays of the same specimen (p = 0.99), (2) the four probe lots (p = 0.33), or (3) the four study days (p = 0.54). There was statistically significant, but not important differences among centers and between readers. The ratios of the HER-2/neu to chromosome 17 copy numbers were estimated with accuracy and precision; the mean ratios (and sd) for specimens, H, E, R, and N were 1.05 (0.06), 1.81 (0.12), 4.48 (0.28), and 8.60 (1.23), respectively. In summary, assays with the LSI HER-2/neu and CEP 17 Dual Color DNA Probe Kit, conducted at three sites by 6 different technicians, over 8 assay days, using kits from four lots, were performed with a high success rate in paraffin-embedded specimens. The signal enumeration was also accurate and precise. This study demonstrated that the results obtained by using the LSI HER-2/neu SpectrumOrange and CEP 17 SpectrumGreen Dual Color DNA Probe Kit are reliable and reproducible.

This article has been cited by other articles:

				L. G. Dressler, D. A. Berry, G. Broadwater, D. Cowan, K. Cox, S. Griffin, A. Miller, J. Tse, D. Novotny, D. L. Persons, et al. Comparison of HER2 Status by Fluorescence in Situ Hybridization and Immunohistochemistry to Predict Benefit From Dose Escalation of Adjuvant Doxorubicin-Based Therapy in Node-Positive Breast Cancer Patients J. Clin. Oncol., July 1, 2005; 23(19): 4287 - 4297. [Abstract] [Full Text] [PDF]

				S. Paik, J. Bryant, E. Tan-Chiu, E. Romond, W. Hiller, K. Park, A. Brown, G. Yothers, S. Anderson, R. Smith, et al. Real-World Performance of HER2 Testing--National Surgical Adjuvant Breast and Bowel Project Experience J Natl Cancer Inst, June 5, 2002; 94(11): 852 - 854. [Abstract] [Full Text] [PDF]

				A. Di Leo, D. Gancberg, D. Larsimont, M. Tanner, T. Jarvinen, G. Rouas, S. Dolci, J.-Y. Leroy, M. Paesmans, J. Isola, et al. HER-2 Amplification and Topoisomerase II{alpha} Gene Aberrations as Predictive Markers in Node-positive Breast Cancer Patients Randomly Treated Either with an Anthracycline-based Therapy or with Cyclophosphamide, Methotrexate, and 5-Fluorouracil Clin. Cancer Res., May 1, 2002; 8(5): 1107 - 1116. [Abstract] [Full Text] [PDF]