Is a Novel Prognostic Methylation Marker in Patients with Oral Squamous Carcinomas: Associations with and Methylation Status.

Staging and pathological grading systems are convenient, but imperfect predictors of recurrence of head and neck squamous cell carcinoma. Therefore, to identify potential alternative prognostic markers, we investigated the methylation status of the promoter of Sal-like protein 2 (). mRNA expression was absent in 8/9 (88.9%) University of Michigan squamous cell carcinoma cell lines, whereas two nonmalignant cell lines had stable expression. The normalized methylation value of in cancer cell lines was significantly higher than in normal cell lines. methylation found in 74 of 233 (31.8%) tumor specimens was correlated with the methylation status of both and . methylation was not associated with any difference in disease-free survival (DFS). Therefore, the presence of methylation was statistically correlated with a decrease in DFS in patients with oral cancer (log-rank test,  = 0.032). Furthermore, it was associated with disease recurrence in 36.2% of oral cancer cases, with an odds ratio of 2.922 (95% confidence interval = 1.198-7.130;  = 0.018) by multivariate Cox proportional hazard regression analysis. This study suggests that cytosine-phosphate- guanosine (CpG) hypermethylation is a likely mechanism of inactivation and supports the hypothesis that could serve as an important clinical risk assessment.