DETECTION OF MUTANT K-RAS IN DISSECTED PARAAORTIC LYMPH-NODES OF PATIENTS WITH PANCREATIC ADENOCARCINOMA

In this study, we attempted to detect K-ras point mutations by means o f two-stage polymerase chain reaction/ restriction fragment length pol ymorphism (PCR/RFLP) to diagnose micrometastases in paraaortic lymph n odes of patients with pancreatic adenocarcinoma. Main carcinoma tissue s and corresponding lymph nodes in the paraaortic region were obtained from 15 patients who underwent extended radical surgery including the wide dissection of lymph nodes and who were diagnosed as lymph node n egative by routine histological examination. DNA was extracted from th e tissue specimens, and PCR/RFLP analysis was used to detect K-ras onc ogene mutations at codon 12. Thirteen of the primary tumors were found to have K-ras mutations. In eight of the 13 cases, 42 of the 101 lymp h nodes showed K-ras point mutations in the paraaortic lymph nodes. Th ese results suggested that PCR/ RFLP analysis is potentially highly se nsitive for the detection of micrometastases in lymph nodes and that i t may be useful in reaching an accurate assessment of the lymphatic di ssemination of pancreatic adenocarcinoma at the molecular level.