PDF(Pubmed)
Abstract：
ALK detection was performed on 2813 EGFR-unmutated NSCLC cases by simultaneous use of immunohistochemistry (VENTANA® anti-ALK D5F3, Roche Molecular Systems, Inc., Rotkreuz, Switzerland) and fluorescence in situ hybridization with the ALK break apart and the ALK/EML4 fusion probe (ZytoVision, Bremerhaven, Germany). A total of 33 cases were positive discordant (FISH-positive, IHC-negative) and 17 cases were negative discordant (FISH-negative, IHC-positive). This study\'s aim was to reevaluate the methods used and compare discordant samples to positive concordant samples in order to ellucidate the differences. FISH signal variants were examined and compared. Positive discordant cases featured one pattern of ALK rearrangement in 41.4%, two patterns in 48.3%, and three patterns in 10.3% of analysed samples, with a higher variability of detected patterns and a higher number of ALK copy gains. Positive concordant cases displayed one pattern of rearrangement in 82%, two patterns in 17.8%, and three patterns in 0.6% of analysed samples. The association between number of patterns and concordance/discordance was statistically significant (p < 0.05). Eleven positive discordant and two negative concordant cases underwent NGS analysis, which resulted in identification of ALK fusion in one positive discordant and two negative discordant cases. Positive protein expression regardless of FISH result correlated more with a positive NGS result compared to samples with a positive FISH result with negative protein expression. FISH analysis was able to detect atypical or heterogenous patterns of rearrangement in a proportion of cases with negative protein expression, which may be associated with more extensive genetic alterations rather than true ALK rearrangement.
摘要：
通过同时使用免疫组织化学（VENTANA®抗ALKD5F3，罗氏分子系统，Inc.,Rotkreuz,瑞士）和荧光原位杂交与ALK分开和ALK/EML4融合探针（ZytoVision，不来梅港,德国)。共有33例阳性不一致（FISH阳性，免疫组化阴性），17例阴性不一致（FISH阴性，IHC阳性）。这项研究的目的是重新评估所使用的方法，并将不一致样品与阳性一致样品进行比较，以确定差异。检查并比较FISH信号变体。阳性不一致病例表现为一种ALK重排模式，占41.4%，48.3%的两种模式，10.3%的分析样本有三种模式，具有较高的检测模式可变性和较高数量的ALK拷贝增益。82％的阳性病例显示一种重排模式，17.8%的两种模式，和0.6%的分析样本中的三种模式。模式数量与一致性/不一致性之间的关联具有统计学意义（p<0.05）。11例阳性不一致和2例阴性一致病例进行了NGS分析，结果在1例阳性不一致和2例阴性不一致病例中鉴定出ALK融合。与具有阳性FISH结果和阴性蛋白质表达的样品相比,不管FISH结果如何,阳性蛋白质表达与阳性NGS结果更相关。FISH分析能够在一定比例的蛋白表达阴性的病例中检测到非典型或异质重排模式。这可能与更广泛的遗传改变有关，而不是真正的ALK重排。
