Role of MGMT as biomarker in colorectal cancer.

Abstract

O(6)-methylguanine DNA methyltransferase (MGMT) gene promoter methylation plays an important role in colorectal carcinogenesis, occurring in about 30%-40% of metastatic colorectal cancer. Its prognostic role has not been defined yet, but loss of expression of MGMT, which is secondary to gene promoter methylation, results in an interesting high response to alkylating agents such as dacarbazine and temozolomide. In a phase 2 study on heavily pre-treated patients with MGMT methylated metastatic colorectal cancer, temozolomide achieved about 30% of disease control rate. Activating mutations of RAS or BRAF genes as well as mismatch repair deficiency may represent mechanisms of resistance to alkylating agents, but a dose-dense schedule of temozolomide may potentially restore sensitivity in RAS-mutant patients. Further development of temozolomide in MGMT methylated colorectal cancer includes investigation of synergic combinations with other agents such as fluoropyrimidines and research for additional biomarkers, in order to better define the role of temozolomide in the treatment of individual patients.

• Authors: Alessandro Inno, Giuseppe Fanetti, Maria Di Bartolomeo, Stefania Gori, Claudia Maggi, Massimo Cirillo, Roberto Iacovelli, Federico Nichetti, Antonia Martinetti, Filippo de Braud, Ilaria Bossi, Filippo Pietrantonio
• Journal: World journal of clinical cases (World J Clin Cases) Vol. 2 Issue 12 Pg. 835-9 (Dec 16 2014) ISSN: 2307-8960 [Print] United States
• PMID: 25516857 (Publication Type: Journal Article, Review)