复发性胸腺瘤PD-L1和p53表达的临床意义

Clinical significance of PD-L1 and p53 expression in recurrent thymoma

目的:分析复发性胸腺瘤PD-L1和p53的表达及与世界卫生组织(WHO)分型的关系。方法:回顾性分析2008年1月至2015年12月于浙江大学医学院附属第二医院行胸腺瘤完整切除术并行组织病理学检查的患者资料,对电话随访有效的患者标本行免疫组织化学标记物PD-L1和p53检测。对复发组和未复发组的WHO分型及免疫组织化学标记物PD-L1和p53的检测结果差异进行统计学分析。结果:纳入20例复发性胸腺瘤(男性13例,女性7例)和61例未复发胸腺瘤(男性27例,女性34例),两组间在WHO分型构成方面差异有统计学意义(P=0.001)。81例胸腺瘤总体复发率为24.69%。各WHO分型复发率中,A型复发率最低(0),C型复发率最高(57.14%),不同分型间复发率差异有统计学意义(P=0.017)。复发组PD-L1表达分值和p53的表达等级分别较未复发组更高(P=0.02和P=0.019)。在所有标本中,PD-L1分值和WHO分型呈显著正相关(r=0.358,P=0.001);PD-L1分值和p53等级呈显著正相关(r=0.317,P=0.004)。结论:WHO分型、PD-L1和p53的表达对预测胸腺瘤复发的不良行为具有重要的临床价值。

Objective:To explore the expression of PD-L1 and p53 in recurrent thymoma and its relationship to the World Health Organization(WHO)classification of thymoma.Methods:We reviewed the histopathological records of patients with a complete thymoma resection between January 2008 and December 2015 at the Second Affiliated Hospital of Zhejiang University School of Medicine.Immunohistochemical staining for PD-L1 and p53 markers was performed on specimens from patients with valid telephone follow-up.WHO classifications and immunohistochemical expression of PD-L1 and p53 in the recurrent and non-recurrent groups were statistically analyzed.Results:Twenty patients of recurrent thymoma(13 males and 7 females)and 61 patients of non-recurrent thymoma(27 males and 34 females)were enrolled.There was a statistically significant difference in the WHO classifications and variants between the recurrent and the non-recurrent groups(P=0.001).The total recurrence rate in 81 cases was 24.7%.Among the WHO classifications,the recurrence rate of type A was the lowest(0%),and the recurrence rate of type C was the highest(57.1%).The differences in the recurrence rate among WHO subtypes were statistically significant(P=0.017).The PD-L1 and p53 expression scores were statistically significantly higher in the recurrent group than those in the non-recurrent group(P=0.02 and 0.019,respectively).In all specimens,there was a significant positive correlation between the PD-L1 expression score and WHO classification(R=0.358,P=0.001);the PD-L1 expression score was shown to significantly positively correlate with p53 expression grade(R=0.317,P=0.004).Conclusions:WHO classification as well as PD-L1 and p53 expression in thymoma could play important roles in predicting harmful recurrent behavior.