METHODS: A total of 3806 participants with primary GCs have been enrolled from 8 hospitals in China. Two primary tumor blocks were selected and recorded as block 1 and block 2 after histological evaluation. An HER2 (4B5) rabbit monoclonal antibody was used for the immunohistochemistry (IHC) analysis.
RESULTS: In total patients, HER2 IHC positive (3+) rate with dual block assessment (9.4%) was higher than that with single block assessment (block 1: 7.8%, block 2: 7.8%) (P < 0.001). Compared with single-block assessment, dual-block assessment increased the positive rate by approximate 20%. Similarly, HER2 equivocal (2+) rate was increased in dual block assessment (25.8%), which was higher than that in single block assessment (block 1: 20.3%, block 2: 20.9%) (P < 0.001). Conversely, dual block assessment demonstrated a lower HER2 negative (0/1+) rate (64.8%) than single block assessment (block1: 71.9%, block 2: 71.3%) (P < 0.001). These findings were also confirmed in individual hospitals.
CONCLUSIONS: Dual block HER2 assessment effectively increased HER2 IHC positive rate in resected specimens of GC. We recommended dual block HER2 assessment be promoted in routine clinical practice in GC.
BACKGROUND: ClinicalTrials.gov, NCT02843412 . Registered 1 July 2016 - Retrospectively registered.
方法:共有来自中国8家医院的3806名初级GCs参与者被纳入研究。选择两个原发性肿瘤块,并在组织学评估后记录为块1和块2。HER2(4B5)兔单克隆抗体用于免疫组织化学(IHC)分析。
结果:在所有患者中,双重区块评估的HER2IHC阳性(3+)率(9.4%)高于单块评估(区块1:7.8%,第2组:7.8%)(P<0.001)。与单块评估相比,双块评估将阳性率提高了约20%。同样,HER2模棱两可(2+)率在双重阻滞评估中增加(25.8%),高于单块评估(块1:20.3%,第2组:20.9%)(P<0.001)。相反,双重阻滞评估显示HER2阴性(0/1+)率(64.8%)低于单一阻滞评估(block1:71.9%,第2组:71.3%)(P<0.001)。这些发现也在个别医院得到证实。
结论:双重阻断HER2评估可有效提高GC切除标本中HER2IHC阳性率。我们建议在GC的常规临床实践中推广双重阻断HER2评估。
背景:ClinicalTrials.gov,NCT02843412。2016年7月1日注册-回顾性注册。