Objective To investigate K-ras gene exon 2 codon 12 and 13 mutations， and analyze the clinical significance in the Uyghur and Han patients with rectal cancer. Methods A total of 144 surgical specimens taken from patients with rectal cancer who were treated in this hospital from January 2010 to December 2011 were used in this study. DNA was picked up from the tumor tissues and amplificated by PCR then direct sequencing.Results The K-ras gene muta-tion rate was 22.22% （32/144）， which was 26.09% （12/46） and 20.41% （20/98） in the Uyghur and Han patients， respec-tively， the difference was not statically significant （P＞0.05）. The K-ras gene mutation was related to the depth of invasion（T1＋T2：25.0%， T3＋T4：75.0%， P=0.01）， which was not related to the nation， gender， location of tumor， differen-tiation degree， or lymph node metastasis （P＞0.05）. Conclusions K-ras gene mutation is a common event in the Uyghur and Han patients with rectal cancer， but the K-ras gene mutation rate is not significant difference between the Uyghur nationality and Han nationality， which is only related to depth of invasion.
ObjectiveTo investigate the clinical significancy of K-ras gene mutation in peripheral blood free DNA in patients with non-small cell lung cancer (NSCLC). MethodsA total of 242 patients pathologically diagnosed with NSCLC in the Third People's Hospital of Chengdu were recruited between January 2013 and August 2015. Both tumor tissues and peripheral blood free DNA were collected for detection of K-ras gene mutation by mutant-enriched liquidchip technology. The detection rate was compared between these two kinds of samples. ResultsIn tumor tissues, the K-ras gene mutation was detected in 12 cases with a positive rate of 4.96%. While in peripheral blood samples, the K-ras gene mutation was detected in 10 cases with a positive rate of 4.13%. The detection yield of K-ras gene mutation in peripheral blood had a good consistency with that of lung cancer tissues (Kappa value=0.81). ConclusionK-ras in peripheral blood plasma free DNA can be a surrogate marker for tumor tissues' K-ras gene mutation in screening patients with NSCLC.