MTAP和p16免疫组化染色联合应用于预测胶质瘤CDKN2A基因纯合性缺失OA

Objective To investigate the sensitivity and specificity of the combined application of MTAP and p16 immunohistochemical(IHC)staining for predicting homozygous deletion(HD)of the CDKN2A gene in glioma.Methods Pathological tissue specimens from 54 patients with primary gliomas who underwent surgical resection were collected.HE staining and fluorescence in situ hybridization(FISH)for the CDKN2A gene were performed.The ex-pression patterns of p16 and MTAP protein were analyzed by IHC analysis,and their relationship with CDKN2A HD was evaluated.Results Among 54 glioma samples,the sensitivity,specificity,accuracy,and misdiagnosis rate of p16 IHC staining for predicting CDKN2A HD were 100％,65.3％,68.5％,and 31.5％,respectively,with a missed diagnosis rate of 0;the sensitivity,specificity,accuracy,and misdiagnosis rate of MTAP IHC staining for predicting CDKN2A HD were 100％,87.8％,88.9％,and 11.1％,respectively,with a missed diagnosis rate of 0.The com-bined use of p16 and MTAP IHC achieved 100％sensitivity,and 0 missed diagnosis rate,98.0％specificity,98.1％accuracy,and only a 1.9％false-positive rate in predicting CDKN2A HD.Conclusion Single p16 or MTAP immuno-histochemistry for determining homozygous deletion of CDKN2A gene has high sensitivity,but poor specificity and a certain misjudgment rate(higher misjudgment rate for p16 than MTAP).Their combined application significantly im-proves specificity,which is valuable for screening and partially replacing genomic testing.However,further FISH or NGS testing may be necessary for double negative gliomas with low-grade histology.