Department of Pathology, Zhongshan Hospital, Fudan University, Shanghai, China.
Department of Pathology, School of Basic Medical Sciences & Zhongshan Hospital, Fudan University, Shanghai, China.
Histopathology. 2017 Oct;71(4):570-579. doi: 10.1111/his.13257. Epub 2017 Jul 19.
HER2 is currently the only biomarker used to select eligible patients with advanced gastric cancer (GC) for targeted therapy. The aims of this study were to verify the value of dual-block HER2 assessment and to explore whether increasing the block number is more beneficial by carrying out a randomized prospective cohort study in which dual-block and all-block HER2 assessment were compared in resected specimens of GC.
Five hundred and forty-nine resected GC specimens were randomly enrolled into two cohorts: a dual-block group (n = 274) with two primary tumour blocks tested, and an all-block group (n = 275) with all primary tumour blocks tested. Immunohistochemical staining of HER2 was performed. For HER2-equivocal (2+) cases, fluorescence in-situ hybridization (FISH) was performed. As compared with single-block assessment, dual-block assessment increased the HER2 immunohistochemistry (IHC)-positive (3+) rate. The rate with dual-block assessment (11.3%) was significantly higher than that with block 1 assessment (8.8%) (P = 0.016) and block 2 assessment (9.1%) (P = 0.031). Similarly, all-block assessment demonstrated a higher HER2 3+ rate (12.4%) than single-block assessment (block 1, 6.5%; block 2, 6.2%; block 3, 7.2%; block 4, 8.7%) (P < 0.05). HER2 3+ rates of all-block and dual-block assessments showed no significant difference (P = 0.703). After IHC and FISH results had been combined, the HER2-positive rate with all-block assessment (13.5%) was slightly higher than that with dual-block assessment (12.0%), although the difference was not statistically significant (P = 0.62).
Dual-block immunohistochemical assessment is an effective, practical and economic approach that is suitable for the preliminary screening of HER2. We recommend that dual-block HER2 assessment be routinely performed on resected specimens of GC. All-block assessment can be a supplement to dual-block assessment if necessary.
HER2 目前是唯一用于选择晚期胃癌（GC）靶向治疗合格患者的生物标志物。本研究旨在通过进行随机前瞻性队列研究来验证双重阻断 HER2 评估的价值，并探讨增加阻断数量是否更有益，该研究比较了切除的 GC 标本中双重阻断和全阻断 HER2 评估。
将 549 例切除的 GC 标本随机纳入两个队列：双阻断组（n = 274），对 2 个原发性肿瘤块进行检测；全阻断组（n = 275），对所有原发性肿瘤块进行检测。对 HER2 进行免疫组织化学染色。对于 HER2 不确定（2+）病例，进行荧光原位杂交（FISH）。与单块评估相比，双阻断评估增加了 HER2 免疫组织化学（IHC）阳性（3+）率。双阻断评估的阳性率（11.3%）明显高于单块评估 1（8.8%）（P = 0.016）和单块评估 2（9.1%）（P = 0.031）。同样，全阻断评估的 HER2 3+率（12.4%）高于单块评估（块 1，6.5%；块 2，6.2%；块 3，7.2%；块 4，8.7%）（P < 0.05）。全阻断和双阻断评估的 HER2 3+率无显著差异（P = 0.703）。IHC 和 FISH 结果结合后，全阻断评估的 HER2 阳性率（13.5%）略高于双阻断评估（12.0%），但差异无统计学意义（P = 0.62）。
双阻断免疫组织化学评估是一种有效、实用和经济的方法，适用于 HER2 的初步筛选。我们建议常规对切除的 GC 标本进行双阻断 HER2 评估。如果需要，全阻断评估可以作为双阻断评估的补充。
