Alkushi Abdulmohsen
Department of Pathology and Laboratory Medicine, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.
Hematol Oncol Stem Cell Ther. 2009;2(3):394-8. doi: 10.1016/s1658-3876(09)50007-6.
Analysis of immunohistochemical expression of a large number of tumor tissue samples with conventional techniques is costly, tedious and slow. Tissue microarray (TMA) technology can facilitate the sampling of over 500 tumors on a one-glass slide, which then can be analyzed by fluorescence in situ hybridization (FISH), RNA in situ hybridization, or immunohistochemistry. We attempted to validate this technique in breast cancer specimens by comparing the staining result obtained by TMA with the conventional whole-section method.
Eighty cases of breast cancer of diverse subtypes were used to build a breast cancer biomarker evaluation model. Serial sections of the recipient block were immunostained with a panel of 4 anti- bodies (ER, PR, HER2 and p53). Concordance of immunohistochemical expression between TMA sections and whole-sections was expressed as a kappa statistic.
Target tumors were accurately sampled by two cores in 19 of 26 donor blocks, and by only one core in 5 blocks. Failure to sample tumor was seen in 2 blocks. Concordance between the staining results of TMA and whole sections was good for PR (kappa=0.67) and ER (kappa=0.67) and very good for p53 (kappa=0.91) and HER2 (kappa=0.91), when all the 26 recipient blocks were included. The rate improved to excellent for p53 (kappa=1.0) and did not change for the other markers when concordance analysis was limited to recipient blocks that had been sampled by two cores.
TMA is a reliable technique for examining a large set of tumors. It shows immunostaining scores comparable to those obtained by conventional whole-section evaluation in breast cancer. However, some alterations are not detected due to heterogeneity of biomarker expression inherent in these tumors, but this shortfall can be improved.
采用传统技术对大量肿瘤组织样本进行免疫组化表达分析成本高、操作繁琐且速度慢。组织微阵列（TMA）技术可在一张载玻片上方便地对500多个肿瘤进行取样，随后可通过荧光原位杂交（FISH）、RNA原位杂交或免疫组化进行分析。我们试图通过比较TMA获得的染色结果与传统全切片方法，在乳腺癌标本中验证该技术。
使用80例不同亚型的乳腺癌构建乳腺癌生物标志物评估模型。受体蜡块的连续切片用一组4种抗体（雌激素受体、孕激素受体、人表皮生长因子受体2和p53）进行免疫染色。TMA切片与全切片之间免疫组化表达的一致性用kappa统计量表示。
在26个供体蜡块中，19个蜡块的目标肿瘤通过两个芯准确取样，5个蜡块仅通过一个芯取样。2个蜡块未取到肿瘤样本。当纳入所有26个受体蜡块时，TMA与全切片染色结果之间的一致性对于孕激素受体（kappa = 0.67）和雌激素受体（kappa = 0.67）良好，对于p53（kappa = 0.91）和人表皮生长因子受体2（kappa = 0.91）非常好。当一致性分析仅限于通过两个芯取样的受体蜡块时，p53的一致性率提高到极佳（kappa = 1.0），其他标志物的一致性率没有变化。
TMA是一种用于检测大量肿瘤的可靠技术。它显示的免疫染色评分与乳腺癌传统全切片评估获得的评分相当。然而，由于这些肿瘤固有的生物标志物表达异质性，一些改变未被检测到，但这一不足可以得到改善。
