Kokate Prajakta, Sawaimoon Satyakam, Bhatia Simi, Mandava Swarna
Cytogenetic Division, Super Religare Laboratories Ltd., Mumbai, India.
Genet Test Mol Biomarkers. 2012 Apr;16(4):239-45. doi: 10.1089/gtmb.2011.0125. Epub 2011 Oct 24.
The HER-2/neu proto-oncogene is amplified in 15%-25% of breast cancers. In the current study, we evaluated HER-2/neu status of 396 cases of breast cancer by fluorescence in situ hybridization (FISH), and the results were correlated with immunohistochemistry (IHC) for HER-2/neu protein expression.
Overall, HER-2/neu amplification was observed in 38.4% of cases. Concordance between IHC and FISH was 90.4% considering only IHC score 0, 1 (negative), and 3 (positive). However, only 37.3% of the IHC score 2 (equivocal) cases showed HER-2/neu gene amplification. A majority of the discordant cases within the IHC negative (score 0 and 1) and IHC positive (score 3) were high-grade tumors. Polysomy 17 and monosomy 17 was seen in 7.3% of the total cases of each. Furthermore, a majority of FISH positive cases were noted in Intraductal Carcinoma grade III and cases with regional lymph nodal metastasis. Polysomy 17 was seen in 7.9% of the FISH positive cases and in 6.3% of the FISH negative cases. Monosomy 17, however was more preponderant in FISH negative cases.
We believe that the FISH test should be considered as the gold standard in the estimation of the HER-2/neu status due to its increased sensitivity and better appreciation of aneusomy 17.
HER-2/neu原癌基因在15%-25%的乳腺癌中呈扩增状态。在本研究中，我们通过荧光原位杂交（FISH）评估了396例乳腺癌病例的HER-2/neu状态，并将结果与HER-2/neu蛋白表达的免疫组织化学（IHC）结果进行关联分析。
总体而言，38.4%的病例观察到HER-2/neu扩增。仅考虑IHC评分为0、1（阴性）和3（阳性）时，IHC与FISH的一致性为90.4%。然而，仅37.3%的IHC评分为2（可疑）的病例显示HER-2/neu基因扩增。IHC阴性（评分为0和1）和IHC阳性（评分为3）的大多数不一致病例为高级别肿瘤。17号染色体多体性和17号染色体单体性在各病例总数中分别占7.3%。此外，在导管内癌III级和有区域淋巴结转移的病例中观察到大多数FISH阳性病例。17号染色体多体性在FISH阳性病例中占7.9%，在FISH阴性病例中占6.3%。然而，17号染色体单体性在FISH阴性病例中更为常见。
我们认为，由于FISH检测具有更高的敏感性以及对17号染色体非整倍性的更好评估，在评估HER-2/neu状态时应将其视为金标准。
