Kai Keita, Yoda Yukie, Kawaguchi Atsushi, Minesaki Akimichi, Iwasaki Hironori, Aishima Shinichi, Noshiro Hirokazu
Department of Pathology, Saga University Hospital, Saga 849-8501, Japan.
Department of Surgery, Saga University Faculty of Medicine, Saga 849-8501, Japan.
World J Clin Cases. 2019 Feb 26;7(4):419-430. doi: 10.12998/wjcc.v7.i4.419.
The needs for human epidermal growth factor receptor 2 (HER-2) and/or programmed death-ligand 1 (PD-L1) evaluations in gastric cancer are dramatically increasing. Although the importance of standardization of sample fixation has been widely recognized, most of the evidence regarding the fixation duration or type of fixing solution are based on breast cancer.
To investigate the real effects of fixation conditions on HER-2 testing or PD-L1 testing for gastric cancer using gastrectomy specimens.
Thirty-two patients who underwent gastrectomy for gastric cancer were enrolled. Their resected specimens were each divided into four pieces and fixed in four strictly controlled different durations (6 h, 24 h, and 48 h, and 1 wk) by 10% formalin ( = 22) or 10% neutral buffered formalin (NBF) ( = 10). Immunohistochemistry (IHC) of HER-2 and PD-1 was performed, and a pathology examination was conducted. In the HER-2-immunoreactive cases, all four specimens were subjected to dual-color in situ hybridization (DISH). Five cases were assessed as HER-2-positive by IHC and DISH. We used the cut-off values of 1%, 10%, and 50% to assess the IHC findings of PD-L1.
No significant difference was observed in comparisons between the shorter fixation period groups (6 h, 24 h, and 48 h) and the prolonged fixation period (1 wk) group in the HER-2 and PD-L1 analyses. Although no significant difference was observed between 10% formalin and 10% NBF within 1 wk of fixation, the superiority of 10% NBF was confirmed in a long-term (> 3 mo) fixation in both the HER-2 and PD-L1 analyses.
In this small-numbered pilot study, prolonged fixation within 1 wk showed no inferiority in HER-2 or PD-L1 testing. However, a large-numbered prospective study is needed to obtain conclusive results.
胃癌中对人表皮生长因子受体2（HER - 2）和/或程序性死亡配体1（PD - L1）评估的需求正在急剧增加。尽管样本固定标准化的重要性已得到广泛认可，但大多数关于固定时间或固定液类型的证据均基于乳腺癌。
使用胃癌切除标本研究固定条件对胃癌HER - 2检测或PD - L1检测的实际影响。
纳入32例行胃癌胃切除术的患者。将他们切除的标本均分成四块，分别用10%福尔马林（n = 22）或10%中性缓冲福尔马林（NBF）（n = 10）在四个严格控制的不同时间（6小时、24小时、48小时和1周）进行固定。对HER - 2和PD - L1进行免疫组织化学（IHC）检测，并进行病理检查。在HER - 2免疫反应性病例中，对所有四个标本进行双色原位杂交（DISH）。5例经IHC和DISH评估为HER - 2阳性。我们使用1%、10%和50%的临界值来评估PD - L1的IHC结果。
在HER - 2和PD - L1分析中，较短固定期组（6小时、24小时和48小时）与延长固定期组（1周）之间的比较未观察到显著差异。虽然在固定1周内10%福尔马林和10% NBF之间未观察到显著差异，但在HER - 2和PD - L1分析中，长期（> 3个月）固定时10% NBF的优势得到证实。
在这项小样本的初步研究中，1周内延长固定在HER - 2或PD - L1检测中未显示劣势。然而，需要进行大样本的前瞻性研究以获得确凿结果。
