The value of serum RASSF10 hypermethylation as a diagnostic and prognostic tool for gastric cancer.

The tumor-suppressing role of Ras-association domain family 10 (RASSF10) has been described in several types of cancers. Here, we evaluated the potential use of the hypermethylation status of the RASSF10 promoter in serum as a new diagnostic and prognostic tool in gastric cancer (GC). We used bisulfite sequencing polymerase chain reaction to examine RASSF10 methylation levels in serum and/or tumor samples from 82 GC, 45 chronic atrophic gastritis (CAG), and 50 healthy control patients. In the serum of GC patients, the median level of RASSF10 methylation was higher at 47.84 % than those in the serum of CAG and healthy control patients at 11.89 and 11.35 %, respectively. The median level of RASSF10 methylation in GC tumor tissue was similarly high at 62.70 %. Furthermore, RASSF10 methylation levels were highly correlated between paired serum and tumor samples from GC patients. We performed receiver-operating characteristic curve analyses to verify that serum RASSF10 methylation levels could effectively distinguish GC from control patients. Moreover, multivariate analyses showed that high serum RASSF10 methylation levels in GC patients were associated with large tumors, lymph node metastasis, and high carcinoembryonic antigen (CEA) levels. Survival analyses showed that GC patients with high serum RASSF10 methylation levels had shorter overall and disease-free survival after D2 lymphadenectomy than those with low levels. High serum RASSF10 methylation levels were also an independent predictor of tumor recurrence and GC patient survival. In conclusion, serum RASSF10 promoter methylation levels can serve as a valuable indicator for the diagnosis and prognosis of GC in the clinic.