PURPOSE The aim of this study was to evaluate the clinicopathological significance and prognostic role of programmed death-1 ligand 2 (PD-L2) expression in colorectal cancer according to intratumoral components. METHODS We used immunohistochemical analysis to investigate the impact of PD-L2 expression on clinicopathological characteristics and survival in 264 human colorectal cancer tissues. We also evaluated the correlation between PD-L2 expression and PD-L1 expression. RESULTS PD-L2 was expressed in 17.4% of the tumors (T-PD-L2) and in 19.3% of the immune cells (I-PD-L2) of the 264 CRC tissues. I-PD-L2 expression was significantly correlated with favorable tumor behaviors, including lower pathologic tumor stage, less lymph node metastasis, less distant metastasis, and lower pathologic tumor node metastasis stage. There was no significant correlation between I-PD-L2 expression and T-PD-L2 expression (P = 0.091). However, I-PD-L2 expression was correlated with PD-L1 expression in the immune cells (P < 0.001). There was also a significant correlation between high Immunoscore and I-PD-L2, but not T-PD-L2 (P < 0.001 and P = 0.190, respectively). The prognosis was better for patients who expressed I-PD-L2 than for patients who did not. In patients who expressed I-PD-L2, there was a significant difference in the survival rate between subgroups according to the presence or absence of T-PD-L2 expression. CONCLUSIONS Our results suggest that I-PD-L2 expression is significantly correlated with favorable tumor behaviors and better survival rates. There is also a significant correlation between PD-L2 expression and PD-L1 expression in immune cells.

中文翻译：

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结直肠癌中程序性死亡1配体2表达的临床病理学意义和预后意义。

目的 本研究的目的是根据肿瘤内成分评估程序性死亡 1 配体 2 (PD-L2) 在结直肠癌中表达的临床病理学意义和预后作用。方法 我们使用免疫组织化学分析来研究 PD-L2 表达对 264 例人类结直肠癌组织的临床病理特征和存活率的影响。我们还评估了 PD-L2 表达和 PD-L1 表达之间的相关性。结果 PD-L2 在 264 个 CRC 组织的 17.4% 的肿瘤 (T-PD-L2) 和 19.3% 的免疫细胞 (I-PD-L2) 中表达。I-PD-L2表达与有利的肿瘤行为显着相关，包括较低的病理肿瘤分期、较少的淋巴结转移、较少的远处转移和较低的病理肿瘤淋巴结转移阶段。I-PD-L2表达与T-PD-L2表达之间无显着相关性（P = 0.091）。然而，I-PD-L2 表达与免疫细胞中的 PD-L1 表达相关（P < 0.001）。高免疫评分与 I-PD-L2 之间也存在显着相关性，但与 T-PD-L2 无关（分别为 P < 0.001 和 P = 0.190）。表达 I-PD-L2 的患者的预后好于不表达的患者。在表达 I-PD-L2 的患者中，根据 T-PD-L2 表达的存在与否，亚组之间的存活率存在显着差异。结论 我们的结果表明，I-PD-L2 表达与有利的肿瘤行为和更好的存活率显着相关。免疫细胞中PD-L2表达与PD-L1表达之间也存在显着相关性。