Background: The methylation of microtubule-associated protein tau (MAPT ) was first described in patients with Alzheimer’s disease. In this study, we aim to determine if MAPT  promoter CpG island is hypermethylated and whether this signature could work as a prognostic marker for patients with stage II colorectal cancer (CRC).
Methods: MAPT  methylation level and CpG island methylator phenotype (CIMP) status were examined. The prognostic value of MAPT  methylation was analyzed using Cox regression analysis.
Results: Amongst stage II CRC patients (n=107), hypermethylation of MAPT  promoter CpG island was seen in 23.4% of them. MAPT  methylation was much more frequent in patients with age ≥60 compared to age <60 (P <0.001). MAPT  were preferentially methylated among proximal colon tumors or CIMP high tumors (both P <0.001). Five-year overall survival (OS) rates were 57.1% and 79.4% for patients with and without MAPT  hypermethylation, respectively, HR=2.33 (95% CI, 1.19–4.57; P =0.014). MAPT  hypermethylation remained an important prognostic variable for OS in multivariate analysis with a HR of 2.29 (95% CI, 1.01–5.18; P =0.047).
Conclusion: Our findings suggest that MAPT  is frequently methylated and hypermethylation is associated with worse prognosis in patients with stage II CRC.
Keywords: colorectal cancer, methylation, MAPT , prognosis