OBJECTIVETo confirm the effect of combined detection of K-ras gene mutation and CA 19-9 level in plasma in the diagnosis of pancreatic carcinoma.

METHODSIn 33 patients without pancreatic carcinoma and 15 patients with pancreatic carcinoma, the value of K-ras mutation and CA 19-9 level were examined by enriched polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) and radioimmunoassay respectively. The data were analysed with chi(2) test, Fisher's exact test and Kruekal-wall's test. All patients were confirmed pathologically.

RESULTSEleven of the 15 patients with pancreatic carcinoma and 2 of 10 patients with chronic pancreatitis were found K-ras mutation. CA 19-9 level in patients with pancreatic cancer was significantly higher than that in those with benign disease but with a low specificity. The sensitivity, specificity of combined detection of K-ras gene mutation and CA 19-9 level in the plasma of patients with pancreatic cancer were 66.67% and 97%. There was a significant difference between patients with pancreatic cancer and those without pancreatic cancer. Pathological examination showed atypical hyperplasia in one patient with chronic pancreatitis who had K-ras mutation and higher CA 19-9 level.

CONCLUSIONSCombined detection of K-ras gene mutation and CA 19-9 can be used for adjuvant diagnosis of pancreatic cancer. It is more specific than detection of single K-ras gene mutation or CA 19-9 level in the plasma. The method is complementary to single detection of K-ras gene mutation or CA 19-9 level because it decreases the rate of false-positive diagnosis.