Detection On Aberrant Methylation Of P16 Gene In The Serum Of Colorectal Cancer Patients

Objective:To explore if there is any difference on aberrant methylationstatus of p16 gene between in the serum and in the tissue of colorectal cancer, andto study the association of the aberrant methylation status of p16 gene with someclinical factors, including tumor size, histologic types, degree of differentiation,Dukeχs stage, lymph node metastasis and family history. Materials﹠Methods: The peripheral blood of 65 cases of colorectal cancerpatients was withdrawn(32 cases of donors as controls),32 cases of cancer and32 paraneoplastic tissues were collected(29 cases of benign disease tissues ascontrols),each sample was detected by methylation-specific PCR (MSP). Results: The aberrant methylation rate of p16 gene in colorectal cancerserum was 61.29%(19/31), and that in donors′ serum was 3.13%(1/32). Therewas significant difference between them (p<0.05). The aberrant methylation rateof p16 gene in benign disease tissues was 3.45%(1/29), and that in colorectalcancer tissues was 56.25%(18/32). There was significant difference between them(p<0.05). The aberrant methylation rate of p16 gene in paraneoplastic tissues was29.41%(5/17), and the rate was significantly (p<0.05) lower than that incolorectal cancer tissues. There is no significant difference between in serum andin the tissue of colorectal cancer (p>0.05). Among 65 cases of colorectal cancerserum, the aberrant methylation rate of tumor size ≤3cm was 80%(4/5), and that>3cm was 60%(36/60). No significant difference was found between them. Sowere the groups of other clinical factors such as histologic types, degree ofdifferentiation, Dukeχs stage, lymph node metastasis and family history(P﹥0.05). Conclusion: There was no difference on the aberrant methylation status ofp16 gene between in serum and in the tissue of colorectal cancer, it is suggestedthat the serum, instead of cancer tissue, could be used to detect the aberrantmethylation of p16 gene. No correlation was found between p16 genemethylation and some of the clinical factors, including tumor size, histologictypes, degree of differentiation, Dukeχs stage, lymph node metastasis and familyhistory.