COMPARISON OF ONCOGENE MUTATION DETECTION AND TELOMERASE ACTIVITY FORTHE MOLECULAR STAGING OF NONSMALL CELL LUNG-CANCER

Novel oncogene mutation detection techniques have demonstrated that st andard histopathological examination may fail to detect clinically sig nificant metastatic cancer cells. Recently, telomerase activity has be en detected in most immortal cell lines and human tumors, potentially providing a novel diagnostic marker. We compared standard histopatholo gical examination with the telomeric repeat amplification protocol ass ay and either a p53 plaque hybridization or a K-ras mutation ligation assay in the lymph nodes of 12 patents with surgically resectable non- small cell lung cancer. Telomerase activity was detected in 10 of 10 ( 100%) evaluable tumors. Eight of 9 (89%) histopathologically positive lymph nodes were telomerase positive, and 26 of 48 (54%) histopatholog ically negative lymph nodes were telomerase positive. In comparison, o ligonucleotide plaque hybridization detected metastases in all 3 histo pathologically positive nodes and in 3 of 27 histopathologically negat ive nodes. Similarly, the K-ras mutation ligation assay detected metas tases in all 6 histopathologically positive lymph nodes examined and i n 1 of 21 histopathologically negative lymph nodes.