Tumor suppressor REC8 as a biomarker for gastric cancer

A method for reducing risk for gastric cancer in a subject, comprising the steps of:

• (a) treating DNA from a sample taken from the subject with an agent that differentially modifies methylated and unmethylated DNA, wherein the sample is a stomach mucosa sample or a plasma or serum sample;
• (b) determining the number of methylated CpGs in a genomic sequence, which is SEQ ID NO:5 or a fragment thereof comprising at least 5 CpGs;
• and
• (c) comparing the number of methylated CpGs from step (b) with the number of methylated CpGs in the genomic sequence from a non-cancer sample of the same type and processed through steps (a) and (b);
• (d) determining the subject, whose sample contains more methylated CpGs in the genomic sequence determined in step (b) compared to the number of methylated CpGs in the genomic sequence from the non-cancer sample of the same type and processed through steps (a) to (b), as having an increased risk for gastric cancer compared with a healthy subject not diagnosed with gastric cancer;
• and
• (e) subjecting the subject who is determined in step (d) as having an increased risk for gastric cancer to (i) reduction or elimination of consumption of foods preserved by drying, smoking, salting, or pickling;
• (ii) regular screening/examination by endoscopy;
• or (iii) testing for infection by Helicobacter pylori.