Correlation of methylthioadenosine phosphorylase (MTAP) protein expression with <i>MTAP</i> and <i>CDKN2A</i> copy number in malignant pleural mesothelioma

Abstract

MTAP is frequently codeleted with CDKN2A in pleural mesothelioma. However, homozygous deletion of both genes occurs in a minority of tumours (5/40; 13%); CDKN2A deletion often co-occurs with heterozygous MTAP deletion or neutral MTAP copy number; and MTAP expression correlates inconsistently with heterozygous MTAP deletion. Correspondingly, MTAP immunohistochemistry is a highly specific but only moderately sensitive assay for CDKN2A deletion.