The purpose was to validate the use of RUNX3 as a potential biomarker for detection of cancer in serum samples and to determine its sensitivity alone and in combination with p16, RASSF1A and CDH1 using methylation-specific polymerase chain reaction (MSP). We examined the promoter methylation status of RUNX3, p16, RASSF1A and CDH1 by MSP using the serum of 70 metastatic breast, non-small cell lung, gastric, pancreatic, colorectal or hepatocellular carcinomas. The DNA from 10 healthy serum controls was used to determine the specificity of methylation. According to our results, promoter hyper-methylation of RUNX3 was detected in the serum of 44 patients comprising breast 9/19 (47%), non-small cell lung 11/20 (55%), gastric 4/4 (100%), pancreatic 2/2 (100%), colorectal 11/17 (65%) and liver 7/8 (88%) carcinomas. Comparative figures for the other genes were as follows: p16 -

A significant discrepancy exists between an initial high interest in testing and actual low uptake. Health programs that address cost issues and education to correct misperceptions may improve genetic information utilization.

Cancer genetics is now an established oncology subspecialty with the primary prevention role of identifying high-risk individuals through genetic information for enrolment into screening and preventive programmes. Integrated into major Western centres since the late 1990s, such a programme has been established in Singapore since 2001. Our programme has evaluated 367 index patients comprising mainly breast and colorectal cancer cases. Cancer patients were receptive to genetic counselling, but cost posed a major barrier to genetic testing. However, when the cost barrier was removed through government subsidy plans, more than half of high-risk patients still declined testing. The major barriers were reluctance to involve family members, perception that the information would not change management, and fears of negative feelings. Confirmed mutation carriers were compliant to screening and receptive to prophylactic surgery. Uptake of predictive testing among cancer-free family members has been low, possibly arising from the stigma associated with cancer in our Asian culture. These potential barriers are being addressed through government subsidy plans, continuing education to increase awareness, and being culturally sensitive when dealing with the Asian family.

Lynch syndrome is an autosomal dominant disorder due to mutations in DNA mismatch repair genes, causing young onset colorectal cancer and extra-colonic cancers such as endometrial and stomach cancers. We genotyped MLH1 and MSH2 in patients suspected to have Lynch syndrome and correlated patient clinical characteristics and family history with deleterious mutations. Eighty-five unrelated patients participated. Comprehensive sequencing was performed for MLH1 and MSH2, including all coding regions, splice-site junctions and promoter regions. Of the 29 different mutations found, 11 were deleterious, of which 10 were in MLH1 and 1 in MSH2. Three recurring MLH1 deleterious mutations were found in two unrelated Chinese patients each, and haplotype analysis suggested common ancestral origin for the recurring mutations and possible founder effect. Families with clinical diagnosis of HNPCC (i.e. family history which fulfills the Amsterdam I/II criteria) was the strongest predictor for finding a deleterious mutation, and stomach cancer was the most commonly reported extra-colonic cancer in families found with a deleterious MLH1 or MSH2 mutation. The observation of recurring deleterious MLH1 mutations in our study suggests possible founder effect and may have implications on genetic testing in Asia.