Molecular detection of p16 promoter methylation in the serum of recurrent colorectal cancer patients.

We previously proved that p16 promoter methylation present in the tumors of colorectal cancer patients can be detected in the serum of those same patients using methylation-specific PCR (MSP). To seek the possibility that this technique could be applied to the monitoring of cancer recurrence, we examined the p16 methylation using MSP. We detected tumor DNA in the serum of 31 of 45 (69%) patients with recurrent colorectal cancer. No methylation was found in serum DNA of 50 patients with colorectal cancers whose corresponding tumor DNA had no methylation in p16 promoter. These results suggested that MSP might be a sensitive and useful method to detect recurrent colorectal cancer in serum.