PURPOSE: Temozolomide (TEM) based therapy has been reported being effective in the treatment of metastatic neuroendocrine neoplasms (NEN), with response rates ranging from 30 to 70%. Among patients affected by advanced glioblastoma or melanoma and treated with TEM, loss of tumoral O6-methylguanine DNA methyltransferase (MGMT) is correlated with improved survival. In NEN patients, the role of MGMT deficiency in predicting clinical outcomes of TEM treatment is still under debate.
METHODS: In this study we evaluated 95 patients with advanced NENs undergoing treatment with TEM-based therapy. MGMT promoter methylation status was evaluated with two techniques: methylation specific-polymerase chain reaction or pyrosequencing.
RESULTS: Treatment with TEM-based therapy was associated with an overall response rate of 27.4% according to RECIST criteria (51.8% of patients with and 17.7% without MGMT promoter methylation). Response to therapy, progression free survival and overall survival was correlated to MGMT status at univariate and multivariate analysis. Methylation of MGMT promoter could be a strong predictive factor of objective response and an important prognostic factor of a longer PFS and OS.
CONCLUSION: According to our results, MGMT methylation status, evaluated with methylation specific-polymerase chain reaction or pyrosequencing, should have an important role in patients with metastatic NENs, in order to guide therapeutic options. These results need further confirmation with prospective studies.
- Aged, 80 and over
- DNA Methylation
- DNA Modification Methylases/genetics
- DNA Repair Enzymes/genetics
- Lung Neoplasms/drug therapy
- Middle Aged
- Neuroendocrine Tumors/drug therapy
- Pancreatic Neoplasms/drug therapy
- Promoter Regions, Genetic
- Retrospective Studies
- Survival Rate
- Temozolomide/therapeutic use
- Treatment Outcome
- Tumor Suppressor Proteins/genetics
- Young Adult