Detection by denaturant gradient gel electrophoresis of tumor-specific mutations in biopsies and relative bronchoalveolar lavage fluid from resectable non-small cell lung cancer

A PCR-denaturant gradient gel electrophoresis (DGGE) method was developed for the detection of p53 and K-ras mutations in primary operable tumors and paired BAL samples of non-small cell lung cancer. Among 36 patients, 9 showed p53 exon V mutations in biopsies and in three paired bronchoalveolar lavage (BAL) specimens with a 33% concordance; Five patients presented p53 exon VI mutations in biopsies and in two paired BALs with a 40% concordance. No mutations were found in p53 exon VII either in biopsies or in paired BAL samples with 100% concordance. Exon VIII mutations were found in six primary tumors and in two BALs with a 33% concordance. Of 36 patients, we detected 7 (19.4%) with K-ras exon I mutations on tumor samples, DGGE analysis of DNA from BAL samples revealed three mutations distributed on K-ras exon I with a 42% overall concordance with respect to tumor tissue. Molecular screening by DGGE of p53-amplified DNA from BAL had cumulative 46.6% sensitivity, 100% specificity, and 77.7% accuracy. DCGE K-ras detection showed 43% sensitivity, 100% specificity; and 88.8% test accuracy. and at relatively low cost but limited by low sensitivity in detecting the presence of neoplastic cells in patients with resectable non-small cell lung cancer.