Liu Y, Wang J F, Li X W, Bu P, Bai W, Li L M
Department of Pathology, Shanxi Medical University, Taiyuan 030001, China.
Zhonghua Bing Li Xue Za Zhi. 2018 Aug 8;47(8):597-602. doi: 10.3760/cma.j.issn.0529-5807.2018.08.006.
To investigate the relationship of PD-L1 protein expression and gene amplification in gastric cancer and their correlation with clinicopathologic factors. The cohort included 247 gastric cancer specimens with follow-up data and clinicopathologic data obtained from Shanxi Cancer Hospital in 2011. PD-L1 expression was detected by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). PD-L1 protein was expressed in 25.9% (64/247) of the tumor cells and 26.7% (66/247) of the tumor infiltrating immune cells (IC). There was a correlation between the two (<0.01). The expression of PD-L1 in tumor cells correlated with the degree of differentiation and tumor diameter(<0.05). The PD-L1 expression in IC correlated with vascular tumor thrombi(<0.05). The amplification rate of PD-L1 gene detected by FISH was 19.0% (47/247), and was associated with age, large/small curvature of the stomach, tumor location, tumor diameter, and lymph node metastasis(<0.05). The positive coincidence rate of the two methods was 25.0% (16/64), negative coincidence rate was 83.0% (152/183), and total coincidence rate was 68.0% (168/247), suggesting that the coincidence of IHC and FISH was poor (=0.157). There was a negative correlation between PD-L1 protein expression on tumor cells and prognosis in gastric cancer. There was no significant correlation between PD-L1 protein expression on IC and PD-L1 gene amplification with prognosis. Vascular tumor thrombi, tumor diameter, depth of invasion, and lymph node metastasis were all poor prognostic factors of gastric cancer(<0.05). Multivariate Cox regression analysis showed that PD-L1 protein expression, depth of invasion and lymph node metastasis were all independent prognostic risk factors for gastric cancer. Concordance between PD-L1 protein expression and gene amplification is poor. PD-L1 protein expression may signify poor prognosis. There is no significant correlation between PD-L1 gene amplification and prognosis of patients with gastric cancer.
探讨胃癌中PD-L1蛋白表达与基因扩增的关系及其与临床病理因素的相关性。该队列包括2011年从山西省肿瘤医院获取的247例具有随访数据和临床病理数据的胃癌标本。通过免疫组织化学（IHC）和荧光原位杂交（FISH）检测PD-L1表达。25.9%（64/247）的肿瘤细胞和26.7%（66/247）的肿瘤浸润免疫细胞（IC）表达PD-L1蛋白。两者之间存在相关性（<0.01）。肿瘤细胞中PD-L1的表达与分化程度和肿瘤直径相关（<0.05）。IC中PD-L1的表达与血管肿瘤血栓相关（<0.05）。FISH检测的PD-L1基因扩增率为19.0%（47/247），且与年龄、胃大/小弯、肿瘤位置、肿瘤直径和淋巴结转移相关（<0.05）。两种方法的阳性符合率为25.0%（16/64），阴性符合率为83.0%（152/183），总符合率为68.0%（168/247），提示IHC和FISH的符合度较差（=0.157）。肿瘤细胞上的PD-L1蛋白表达与胃癌预后呈负相关。IC上的PD-L1蛋白表达与PD-L1基因扩增和预后之间无显著相关性。血管肿瘤血栓、肿瘤直径、浸润深度和淋巴结转移均为胃癌的不良预后因素（<0.05）。多因素Cox回归分析显示，PD-L1蛋白表达、浸润深度和淋巴结转移均为胃癌独立的预后危险因素。PD-L1蛋白表达与基因扩增之间的一致性较差。PD-L1蛋白表达可能预示预后不良。PD-L1基因扩增与胃癌患者预后无显著相关性。
