ABSTRACT
Objective:To investigate the relationship between primary resection and KRAS gene mutation in the mild symptomatic patients with stage Ⅳ colorectal cancer,and to clarify its significance of prognosis.Methods:The clinical data of 46 mild symptomatic patients with stage Ⅳ colorectal cancer 2010 to December 2010 were collected.All the patients received primary resection.The KRAS gene mutation in the patients was detected by direct sequencing and the patients were followed up for 5 years.The influence of primary resection and KRAS gene mutation in prognosis of the patients with stage Ⅳ colorectal cancer was analyzed, and the clinical pathological features which might influence the prognosis were analyzed by survival analysis.Results:In 46 patients with colorectal cancer, KRAS gene mutation was found in 20 cases, the mutation rate was 43.4%, and most mutation was found at Codon 12. The KRAS mutation had relationship with the tumor site and multiple metastasis (P0.05).The median survival time of right colon cancer patients was 34.2 months, the median survival time of left colon cancer patients was 58.3 months, and there was sigificant difference (P<0.05).The cancer metastases including liver, lung and multiple metastasis were closely related to the poor prognosis of the colorectal cancer patients(P<0.05).The median survival time of the patients with stage Ⅳ colorectal cancer was 39.6 months after operation.Conclusion:After primary resection of the mild symptomatic patients with stage Ⅳ colorectal cancer,the median survival time of the patients with colorectal cancer in left colon site and right colon site were prolonged.Right colon cancer has more poorer prognosis than left colon cancer.KRAS gene mutation is associated with the tumor site and the multiple metastasis.The location of metastasis affect the prognosis.
ABSTRACT
Objective The purpose of this study was to investigate the feasibility of short tandem repeat(STR) genotyping of cell free DNA in plasma for individual identification and paternity testing. Methods EDTA-Na2 DNA anti-coagulant blood samples were collected from 36 unrelated healthy volunteers,and both DNA in leukocytes and cell free DNA in plasma were extracted respectively using phenol-chloroform method. Target DNA in blood cells and plasma were amplified using regular STR typing and fluorescent multiplex STR assay separately,accordingly,the PCR products were analyzed by polyacrylamide gel electrophoresis and capillary electrophoresis. Results Using either normal PCR-STR or fluorescent multiplex STR assay,the consistent STR genotyping results were detected with similar efficiency for cell DNA and plasma DNA samples from the same individual. Conclusion Cell free DNA in plasma samples can be used as useful biological samples for STR genotyping,which can be applied to individual identification and paternity testing in forensic practice.