Association Between MGMT Promoter Methylation and Breast Cancer: a Meta-Analysis

Numerous studies have suggested that the promoter methylation status of O6-methylguanine-DNA methyltransferase (MGMT) is significantly associated with breast cancer. However, these studies have not demonstrated consistent results.

To obtain more accurate results for this possible association, we performed a meta-analysis-based study using the relevant data. A total of 14 articles were included in this meta-analysis.

Our study showed that the frequency of MGMT promoter methylation was significantly higher in patients with breast cancer than non-breast cancer subjects with an Odds Ratio (OR) of 4.47, a 95% Confidence Interval (CI) ranging between 1.95 - 10.25 and a P value of 0.0004. Moreover, MGMT methylation was significantly associated with the negative expression of the MGMT protein (OR = 4.65, 95%CI = 2.66 - 8.12, P < 0.00001), Oestrogen Receptor (ER)-negative tumours (OR = 1.79, 95%CI = 1.09 - 2.93, P = 0.02), postmenopausal status (OR =1.84, 95%CI = 1.18 - 2.87, P = 0.007) and histological grade III tumours (OR = 2.49, 95%CI = 1.53 - 4.07, P = 0.0003) in breast cancer patients. However, breast cancer was not significantly correlated with lymph node metastasis (OR = 1.19, 95%CI = 0.83 - 1.70, P = 0.35), Progesterone Receptor (PR) status (OR = 1.08, 95%CI = 0.58 - 2.00, P = 0.81), Human epidermal growth factor receptor - 2（HER-2/neu）status (OR = 1.01, 95%CI = 0.65 - 1.57, P = 0.97), P53 mutation (OR = 1.30, 95%CI = 0.76 - 2.21, P = 0.34) and age > 50 (OR = 1.07, 95%CI = 0.46 - 2.51, P = 0.88).

Our study suggests that MGMT promoter methylation may be an early biomarker for the diagnosis of breast cancer.