hTERT Expression in Non-cancerous Bronchial Epithelia as a Possible Marker of Early Development of Squamous Cell Lung Cancer

Abstract

Although properly selected candidates for PDT with centrally located early-stage lung cancer have a good therapeutic outcome, some cases develop recurrence or multiple metachronous cancers shortly after successful PDT. We selected the patients with early stage lung cancer who were treated by PDT and followed for a long term after PDT. The preserved bronchial biopsy specimens taken from them were retrospectively examined for the expression of the telomerase protein i.n situ, by immunohistochemistry. While the patients who achieved long term CR after PDT showed no telomerase protein expression in non-cancerous epithelia, the patients who developed recurrence or multiple metachronous cancers showed positive telomerase protein expression in adjacent bronchial epithelia diagnosed as "normal epithelia" by H-E staining before cancer development. We propose that the detection of hTERT protein expression in non-cancerous bronchial epithelia in situ might become a possible indicator of a high-risk of developing lung cancer after PDT.