Reşit Doğan KÖSEOĞLU, Jülide Saliha CAFERLER, Ahmet MÜSLEHİDDİNOĞLU, Pervin DÜRER, Ünal ERKORKMAZ, Yavuz Hakan ÖZÖN

An analysis of HER-2/neu gene status in invasive ductal carcinomas using immunohistochemistry and fl uorescence in situ hybridization

Amaç: İnvaziv meme karsinomalarında HER-2/neu gen durumunu belirlemek için immünohistokimya (İHK) ve fl uoresan in situ hibridizasyon (FİSH) en sık olarak kullanılan 2 metotdur. Çalışmamızdaki amacımız invaziv duktal karsinoma olgularımızda HER-2/neu geni için İHK ve FİSH ile elde edilen sonuçlar arasındaki uyumu analiz etmekti. Yöntem ve gereç: Çalışmaya invaziv duktal karsinoma tanısı konmuş 59 kadın hasta dahil edildi. Ortalama yaş 57,8 idi. Aksiller lenf düğümü durumu, aksiller disseksiyon uygulanmış 30 hastada değerlendirilebildi. HER-2/neu gen ekspresyonu ve amplifikasyonu primer tümör dokularında İHK ve FİSH metotları ile analiz edildi. İHK analizini yorumlamak için skor 0, 1+, 2+ ve 3+ şeklinde skorlama uygulanırken HER-2/neu : CEP17 oranı 2 ve üzerinde olan olgular HER-2/neu gene amplifi kasyonu için pozitif kabul edildi. Bulgular: Çalışmamızda olguların tamamı dikkate alındığında HER-2/neu gen amplifi kasyon oranı % 28,8 (17 olgu) iken bu oran lenf düğümü pozitif grupta % 48 (12 olgu) idi. Serimizde HER-2/neu aşırı ekspresyon (skor 3+) oranı % 11,9 olarak saptandı (7 olgu). HER-2/neu gen amplifi kasyonu tümör derecesi ile ilişkiliydi (P < 0,05). İHK ve FİSH sonuçları arasındaki ilişki anlamlıydı (P < 0,001). Skore 3+ olan olguların tümü FİSH pozitif iken skor 0 olanların % 97’si, skor 1+ olanların % 44’ü FİSH negatif idi. Skore 2+ olguların % 80’ inde HER-2/neu gen amplifi kasyonu saptandı. Lenf düğümü pozitif skor 0, 2+ ve 3+ olgularda İHK ve FİSH sonuçları arasındaki uyum oranı % 100 iken skor 1+ olgularda bu oran % 29 idi. Sonuç: Sonuç olarak, kendi serimizdeki HER-2/neu aşırı ekspresyon oranı (% 11,9) literatürde rapor edilmiş oranlardan düşük iken HER-2/neu gen amplifikasyon oranı (% 28,8) literatür ile uyumluydu. Çalışmamızda HER-2/neu gen amplifikasyonu tümör derecesi ile ilişkiliydi. Skor 2+ ve 3+ olgularda HER-2/neu aşırı ekspresyon ve gen amplifikasyon sonuçları arasındaki uyum oranı yüksek iken skor 1+ olgulardaki uyumsuzluk oranı diğer rapor edilmiş oranlara göre daha yüksekti. Pozitif lenf düğümlü skor 1+ olgulardaki uyumsuzluk oranı total çalışma grubununkinden daha yüksekti. Sonuçlarımıza göre, HER-2/neu için skor 1+ immünboyanma daha belirsiz bir sonuçtu ve metastatik hasta grubunda skor 1+ olgular çalışma grubunun tamamından daha yüksek HER-2/neu gen amplifikasyon oranına sahipti. Sonuçlarımız, özellikle aksiller lenf düğümü pozitif olan skor 1+ olgularda HER-2/neu gen durumunun FİSH analizi ile değerlendirilmesi gerektiğine işaret etmektedir.

İnvaziv duktal karsinomalarda immünohistokimya ve floresan in situ hibridizasyonu ile HER-2/neu gen analizi

Aim: To determine the concordance rates between results from immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) assays for the HER-2/neu gene in cases of invasive ductal carcinoma. IHC and FISH are 2 of the most frequently used methods to determine HER-2/neu gene status in invasive breast carcinomas. Materials and methods: The present study includes 59 female patients with invasive ductal carcinoma. The mean age was 57.8 years. Axillary lymph node status could be evaluated in 30 patients with axillary dissection. HER-2/neu gene overexpression and amplification were analyzed in primary tumor tissues by IHC and FISH assays, respectively. The evaluation of the IHC assay was performed using a score of 0, 1+, 2+, or 3+, while a HER-2/neu-to-CEP17 ratio greater than 2 was accepted as positive for HER-2/neu gene amplification. Results: The overall rate of HER-2/neu gene amplification was 28.8% (17 cases) among all members of the study group, while this rate was 48% (12 cases) in the group with axillary lymph node metastasis. The rate of HER-2/neu overexpression (score of 3+) was 11.9% (7 cases). HER-2/neu gene amplification was associated with tumor grade (P < 0.05). There was a significant relationship between the results of the IHC and FISH assays (P < 0.001). All of the cases with a score of 3+ were FISH-positive, while 97% of cases with a score of 0 and 44% of cases with a score of 1+ were FISH-negative. HER-2/neu gene amplifi cation was determined in 80% of the cases with a score of 2+. Among cases with positive lymph node status, the concordance rates were 100% in cases with scores of 0, 2+, and 3+, while this rate was found to be 29% in cases with a score of 1+. Conclusion: Our found rate (11.9%) of HER-2/neu overexpression was lower than the rates reported in the literature, while our HER-2/neu gene amplification rate (28.8%) was compatible with the reported rates. HER-2/neu gene amplification was associated with tumor grade. Although high rates of concordance between HER-2/neu gene overexpression and amplification in cases with scores of 2+ and 3+ were obtained, the discordance rate in cases with a score of 1+ was higher than those of other studies. The discordance rate in cases with a score of 1+ and positive lymph node status was higher than that of the total study group. According to our results, a score of 1+ indicated less conclusive immunostaining for the HER-2/neu gene, and cases with scores of 1+ in the metastatic group had a higher rate of HER- 2/neu gene amplifi cation than that of the total study group. Our results show that FISH analysis for HER-2/neu gene status should be performed in cases with an immunostaining score of 1+, especially in those cases with positive axillary lymph node results.

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