Although still limited by sensitivity, molecular diagnostic strategies can detect the presence of neoplastic cells in the proximal airway of patients with surgically resectable NSCLC.

The p53 gene was sequenced in 100 primary human lung cancers by using direct dideoxynucleotide cycle sequencing and compared with sequence analysis by using the p53 GeneChip assay. Differences in sequence analysis between the two techniques were further evaluated to determine the accuracy and limitations of each method. p53 mutations were either detected by using both techniques or, if only detected by one technique, were confirmed by using mutation-specific oligonucleotide hybridization. Dideoxynucleotide sequencing of the conserved regions of the p53 gene (exons 5-9) detected 76% of the mutations within this region of the gene. The GeneChip p53 assay detected 81% of all (exons 2-11) mutations, including 80% of the mutations within the conserved regions of the gene. The GeneChip assay detected 46 of 52 missense mutations (88%), but 0 of 5 frameshift mutations. The specificity of direct sequencing and of the p53 GeneChip assay at detecting p53 mutations were 100% and 98%, respectively. The GeneChip p53 assay is a rapid and reasonably accurate approach for detecting p53 mutations; however, neither direct sequencing nor the p53 GeneChip are infallible at p53 mutation detection.

This study further supports the role of BLA as an effective treatment option for patients with ACTH-dependent Cushing's syndrome.

We surveyed the occurrence of novel alleles at microsatellite sequences in non‐small cell lung cancers (NSCLC) using 61 tetranucleotide repeat markers. The presence of at least one new allele, consistent with microsatellite instability (MSI), was observed in 26 of 61 (43%) markers involving 30 of 47 (64%) NSCLC. Twelve of the 26 markers detected new alleles in 2 or more tumors and 11 of these 12 markers contained an AAAG repeat sequence. Using this panel of 12 markers, MSI was detected in 24 of 47 (51%) NSCLC and 10 of 18 (56%) head and neck cancers but was only observed in 8 of 38 (21%) bladder cancers and 3 of 25 (12%) kidney cancers. Our results suggested that about 50% of respiratory tract cancers exhibited microsatellite instability predominantly at AAAG sequences. This distinct type of instability was termed EMAST for elevated microsatellite alterations at selected tetranucleotide repeats. The identification of markers with EMAST should have potential application for the molecular detection of respiratory tract cancers. © 2001 Wiley‐Liss, Inc.