Background: Tumor-infiltrating natural killer (NK) cells (TINKs) are crucial immune cells in tumor defense, and might be related to tumor prognosis. However, the results were discrepant among different studies. The present meta-analysis was performed to comprehensively assess the prognostic value of NK cell markers in solid tumor tissues.

Methods: PubMed, Web of Science, and EMBASE were searched to identify original researches reporting the prognostic significance of TINKs in solid tumors. NK cell markers CD56, CD57, NKp30, and NKp46 were included in the analysis. The hazard ratios (HRs) and 95% confidence intervals (CIs) of pooled overall survival (OS), disease-free survival (DFS), metastasis-free survival (MFS), progression-free survival (PFS), and recurrence-free survival (RFS) were calculated by STATA software 14.0 to assess the prognostic significance.

Results : Of the 56 included studies, there were 18 studies on CD56, 31 studies on CD57, 1 study on NKp30, and 7 studies on NKp46. High levels of CD56, CD57, NKp30, and NKp46 were significantly correlated with better OS of patients with solid malignancies (HR = 0.473, 95%CI: 0.315–0.710, p < 0.001; HR = 0.484, 95%CI: 0.380–0.616, p < 0.001; HR = 0.34, 95%CI: 0.14–0.80, p = 0.014; HR = 0.622, 95%CI: 0.470–0.821, p < 0.001, respectively). Our results also revealed that CD56, CD57, and NKp46 could act as independent prognostic predictors for favorable OS (HR = 0.372, 95%CI: 0.261–0.531, p < 0.001; HR = 0.525, 95%CI: 0.346–0.797, p = 0.003; HR = 0.559, 95%CI: 0.385–0.812, p = 0.002, respectively).

Conclusions : Our results indicated that high levels of NK cell markers in solid tumor tissues could predict favorable prognosis for solid tumor patients.

背景：肿瘤浸润性自然杀伤细胞（NK）是肿瘤防御中至关重要的免疫细胞，可能与肿瘤的预后有关。但是，不同的研究结果不一致。进行本荟萃分析以全面评估实体瘤组织中NK细胞标志物的预后价值。

方法：搜索PubMed，Web of Science和EMBASE以确定报道TINK在实体瘤中的预后意义的原始研究。NK细胞标记CD56，CD57，NKp30和NKp46包括在分析中。合并总生存期（OS），无病生存期（DFS），无转移生存期（MFS），无进展生存期（PFS）和无复发的风险比（HRs）和95％置信区间（CIs）通过STATA软件14.0计算生存率（RFS）以评估预后的意义。

结果：在纳入的56项研究中，有18项针对CD56的研究，31项针对CD57的研究，1项针对NKp30的研究和7项针对NKp46的研究。高水平的CD56，CD57，NKp30和NKp46与实体恶性肿瘤患者的OS更好相关（HR = 0.473，95％CI：0.315–0.710，p<0.001; HR = 0.484，95％CI：0.380–0.616，p<0.001; HR = 0.34，95％CI：0.14-0.80，p= 0.014; HR = 0.622，95％CI：0.470–0.821，p分别<0.001）。我们的研究结果还表明，CD56，CD57和NKp46可以作为有利于OS的独立预后指标（HR = 0.372，95％CI：0.261-0.531，p<0.001; HR = 0.525，95％CI：0.346–0.797，p= 0.003; HR = 0.559，95％CI：0.385–0.812，p 分别为0.002）。

结论： 我们的结果表明，实体瘤组织中高水平的NK细胞标志物可以预测实体瘤患者的预后。