内容紹介
Comparison of HER2 Immunohistochemical Results for Advanced Gastric Cancer Obtained on Using 3 Different Antibodies
Summary
We compared the results of immunohistochemical assessment of HER2 expression in 107 samples of advanced gastric cancer on using 3 currently used antibodies. Expression was scored as 0 to 3+, and equivocal or discordant cases were subjected to fluorescence in situ hybridization(FISH)analysis. HER2 scores of 2+ or 3+ were noted in 16.8% of cases(18/107)using SV2-61γ, in 29.9% of cases(32/107)using Dako HercepTest, and in 34.6% of cases(37/107)using 4B5. The results of the HER2 test differed according to the antibodies used for immunohistochemistry preceding FISH analysis, and the HER2 positive rates after the FISH analysis were 14.0%(15/107)using SV2-61γ, 19.6%(21/107)using Dako HercepTest, and 22.4%(24/107)using 4B5. Thus, therapeutic decisions might be considerably influenced by the antibody used for the HER2 test.
要旨
107例の原発進行胃癌に対して3種の抗体(SV2-61γ,Dako HercepTest,4B5)を用いたHER2検査を行い,その判定結果を比較した。HER2検査は免疫染色を先行し,いずれかの抗体でHER2 score 2+と判定されるか,いずれかの抗体間でHER2 scoreが2段階以上異なる症例についてはfluorescence in situ hybridization(FISH)解析を行った。各抗体のHER2 score 2+あるいは3+の割合は,SV2-61γで16.8%(18/107),Dako HercepTestで29.9%(32/107),4B5では34.6%(37/107)であり,FISH解析を加えた最終的なHER2検査陽性率はSV2-61γで14.0%(15/107),Dako HercepTestで19.6%(21/107),4B5では22.4%(24/107)であった。使用する一次抗体によってHER2検査の結果が異なる場合があり,その要因と今後の課題について考察した。
目次
Summary
We compared the results of immunohistochemical assessment of HER2 expression in 107 samples of advanced gastric cancer on using 3 currently used antibodies. Expression was scored as 0 to 3+, and equivocal or discordant cases were subjected to fluorescence in situ hybridization(FISH)analysis. HER2 scores of 2+ or 3+ were noted in 16.8% of cases(18/107)using SV2-61γ, in 29.9% of cases(32/107)using Dako HercepTest, and in 34.6% of cases(37/107)using 4B5. The results of the HER2 test differed according to the antibodies used for immunohistochemistry preceding FISH analysis, and the HER2 positive rates after the FISH analysis were 14.0%(15/107)using SV2-61γ, 19.6%(21/107)using Dako HercepTest, and 22.4%(24/107)using 4B5. Thus, therapeutic decisions might be considerably influenced by the antibody used for the HER2 test.
要旨
107例の原発進行胃癌に対して3種の抗体(SV2-61γ,Dako HercepTest,4B5)を用いたHER2検査を行い,その判定結果を比較した。HER2検査は免疫染色を先行し,いずれかの抗体でHER2 score 2+と判定されるか,いずれかの抗体間でHER2 scoreが2段階以上異なる症例についてはfluorescence in situ hybridization(FISH)解析を行った。各抗体のHER2 score 2+あるいは3+の割合は,SV2-61γで16.8%(18/107),Dako HercepTestで29.9%(32/107),4B5では34.6%(37/107)であり,FISH解析を加えた最終的なHER2検査陽性率はSV2-61γで14.0%(15/107),Dako HercepTestで19.6%(21/107),4B5では22.4%(24/107)であった。使用する一次抗体によってHER2検査の結果が異なる場合があり,その要因と今後の課題について考察した。