A highly sensitive method for K-ras mutation detection is useful in diagnosis of gastrointestinal cancer

Detection of molecular features such as K-ras mutations has been used to ev aluate potential tumour markers in a wide variety of clinical samples. Here we have applied a recently developed highly sensitive method for detection of K-ras codon IZ mutations to colorectal and pancreatic cancer diagnosis. We analysed 67 faecal samples from patients undergoing diagnostic colonosc opy under suspicion of colorectal cancer. PCR products were obtained in 62 of 67 (93%) faecal samples. Mutations were detected in exfoliated cells in 6 of 22 (27%) of the adenomas and in 6 of 11 (55%) of adenocarcinomas. No f alse positives were observed. Agreement between faecal samples and correspo nding tissues was 100% for adenocarcinomas and 65% for adenomas. Mutations were also analysed in 61 pancreatic fine-needle aspirates. Mutations were d etected in 36 of 45 (80%) of the pancreatic aspirates diagnosed as pancreat ic cancer without false positives. Our findings suggest that, when colorect al cancer is suspected, detection of K-ros codon IZ mutations in faecal sam ples using this new method is specific for colorectal tumours, Additionally , this technique is a good alternative for evaluation of pancreatic masses. (C) 2000 Wiley-Liss, Inc.