Pala Emel Ebru, Bayol Ümit, Özgüzer Alp, Küçük Ülkü, Akdeniz Çağlar Yıldız, Sezer Özlem
Clinic of Pathology, İzmir Tepecik Training and Research Hospital, İzmir, Turkey.
J Breast Health. 2015 Jan 1;11(1):10-16. doi: 10.5152/tjbh.2014.2103. eCollection 2015 Jan.
Human epidermal growth factor receptor 2 (HER2) oncoprotein is overexpressed in 15-25% of breast carcinomas and associated with poor outcome. Assessment of HER2 status accurately is important to select patients who will benefit from targeted therapy.
In this study immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) were used to determine the HER2 status in 308 breast carcinoma cases of which 129 were consultation. The major problems in determining HER2 status and the reasons of discordant results between methods were discussed.
HER2 expression was (-) in 124, (+) in 29, (++) in 92, (+++) in 63 cases. 25 of 76 cases consulted as (++) were evaluated as (++) and 15 of 35 cases consulted as (+++) were evaluated as (+++). HER2 amplification was found in 88 (28.6%) of 308 cases by FISH. 3 of 124 (-), 1 of 29 (+), 22 of 92 (++), 62 of 63 (+++) cases were amplified by FISH. The relation between HER2 expression and amplification was statistically significant (p<0.001). Centromere 17 (CEN 17) region amplification was noted in 11 cases of which 2 were (+++), 9 were (++). 6 of the 11 cases showed focal low level, 1 of them showed diffuse high level amplification.
The concordance rate between IHC (+++) cases and FISH was 95.4% for consultation cases, 100% for our cases. The final concordance rate for both case groups was 98.4%. The possible reasons of discrepancy were triple negativity, preanalytical and analytical procedures of consultation cases and trucut samples.
人表皮生长因子受体2（HER2）癌蛋白在15%-25%的乳腺癌中过度表达，并与不良预后相关。准确评估HER2状态对于选择能从靶向治疗中获益的患者很重要。
本研究采用免疫组织化学（IHC）和荧光原位杂交（FISH）检测308例乳腺癌病例的HER2状态，其中129例为会诊病例。讨论了确定HER2状态的主要问题以及不同方法结果不一致的原因。
124例HER2表达为（-），29例为（+），92例为（++），63例为（+++）。会诊病例中76例被诊断为（++）的病例中有25例评估为（++），35例被诊断为（+++）的病例中有15例评估为（+++）。FISH检测发现308例中有88例（28.6%）存在HER2扩增。124例（-）中的3例、29例（+）中的1例、92例（++）中的22例、63例（+++）中的62例通过FISH检测发现有扩增。HER2表达与扩增之间的关系具有统计学意义（p<0.001）。11例检测到17号染色体着丝粒（CEN 17）区域扩增，其中2例为（+++），9例为（++）。11例中的6例显示局灶性低水平扩增，1例显示弥漫性高水平扩增。
会诊病例中IHC（+++）病例与FISH的符合率为95.4%，我们的病例为100%。两个病例组的最终符合率为98.4%。差异的可能原因是三阴性、会诊病例和粗针穿刺样本的分析前和分析过程。
