背景:色素上皮衍生因子(PEDF)是一种分泌蛋白,可强烈抑制血管生成并直接抑制癌细胞增殖。已经在多种类型的人类肿瘤中观察到PEDF的差异表达。然而,目前尚不清楚PEDF表达如何与癌症进展相关,以及PEDF是否可以作为癌症患者的预后标志物.
方法:我们对14种发病率最高的实体肿瘤中PEDF表达的研究进行了全面搜索。使用系统方法筛选合格的研究并提取数据。进行荟萃分析以研究PEDF表达是否与TNM分期相关。肿瘤大小,淋巴结浸润,远端转移和肿瘤病理分级以泛癌的方式进行。用数字重建的患者生存数据绘制Kaplan-Meier曲线,以研究PEDF表达对癌症患者预后的影响。
结果:共选择了9项研究,回顾和分析。Meta分析提示PEDF蛋白表达降低与TNM分期升高相关(OR=2.13,95%CI:1.61-2.81),肿瘤大小较大(OR=1.42,95%CI:1.1-1.84),淋巴结浸润可能性较大(OR=1.68,95%CI:1.26~2.22),病理分级较高(OR=1.6,95%CI:1.2~2.13)。PEDF表达与肿瘤远端转移无相关性,性别或年龄。此外,肿瘤组织中PEDF蛋白水平低与总生存期短相关(P<0.05)。
结论:PEDF蛋白在癌症中的低表达与更晚期的癌症进展和显著较差的生存期显著相关。具有各种PEDF表达的患者之间的差异临床结果提示其预后价值。
BACKGROUND: Pigment epithelium derived factor (PEDF) is a secreted protein that strongly suppresses angiogenesis and directly inhibits cancer cells proliferation. The differential expression of PEDF has been observed in multiple types of human tumors. However, it is unclear as to how PEDF expression is associated with cancer progression and if PEDF could serve as a prognostic marker for cancer patients.
METHODS: We performed a comprehensive search for the studies on PEDF expression in 14 top-ranked types of solid tumor cancer with the highest incidence. A systemic approach was used to screen for qualified studies and to extract data. Meta-analysis was performed to investigate if PEDF expression is associated with the TNM staging, tumor size, lymph node invasion, distal metastasis and pathological grade of tumor in a pan-cancer manner. A Kaplan-Meier curve was plotted with the digitally-reconstituted patient survival data to
study the effect of PEDF expression on the prognosis of cancer patients.
RESULTS: A total of nine studies were selected, reviewed and analyzed. Meta-analysis suggested that decreased PEDF protein expression was associated with higher TNM staging (OR = 2.13, 95% CI: 1.61-2.81), larger tumor size (OR = 1.42, 95% CI: 1.1-1.84), larger possibility of lymph node invasion (OR = 1.68, 95% CI: 1.26-2.22) and higher pathological grade (OR = 1.6, 95% CI: 1.2-2.13). No correlation was found between PEDF expression and tumor distal metastasis, gender or age. In addition, low PEDF protein level in tumor tissue is correlated with shorter overall survival (P < 0.05).
CONCLUSIONS: Low PEDF protein expression in cancer is significantly associated with more advanced cancer progression and significantly poorer survival. The differential clinical outcome among patients with various PEDF expression suggests its prognostic value.