ALTERATION IN LENGTH OF TELOMERIC REPEATS IN LUNG-CANCER

We investigated the relationship between telomere length and various c haracteristics of tumor cells in 46 lung cancer specimens (40 primary lesions and six metastatic lesions). Three variant patterns of telomer e length were observed in 16 cases (34.8%): reduction in 13 cases, elo ngation in two cases, and convergence in one case. These variant patte rns were frequently observed in small cell carcinomas, in metastatic l esions, and in cases which possesed the S-type allele of the L-myc gen e. All three cases with telomere elongation or convergence were associ ated with a poor prognosis. This is compatible with the previous repor t suggesting that telomerase activity may be an indicator of immortali ty in vitro. In adenocarcinoma, telomere reduction or elongation was a lso observed in the early stages with a low percentage of cells in the S-phase, while in cases with other histologic types, these changes we re observed only in late stage, in metastatic lesions, or in cancerous tissues with a high percentage of cells in the S-phase. Although the reduction of telomere length in these tissues may be a result-of many cell divisions, it may represent another stage of carcinogenesis in ea rly-stage adenocarcinoma.