Incision of AP sites in lung cancer patients: a pilot study.

DNA base excision repair (BER) removes frequent DNA lesions of either endogenous or exogenous origin. Some indications point to BER defects in lung cancer patients. We have investigated the ability of ten lung cancer patients to repair natural AP sites, the most frequent genetic lesion, using an in vitro assay in which peripheral blood lymphocytes (PBL) extracts incise randomly depurinated plasmid DNA. The median value of repair activity in patients was lower than that of matched controls but the difference did not reach significance. Unlike other BER enzymatic steps, marked defects in incision of AP sites may not be associated with lung carcinogenesis.