DNA repair: A potential marker for cancer susceptibility
DNA REPAIR in the etiology of cancer has been implicated in a rare genetic disease, xeroderma pigmentosum. Deficient repair and an extraordinarily high incidence of sunlight-induced skin cancers are coupled in xeroderma pigmentosum patients, which led to the pursuit of DNA repair capacity as a biomarker of cancer susceptibility. Recently a new assay (host cell reactivation [HCR] or chloramphenicol acetyltransferase [CAT] assay) was developed to measure the overall DNA repair capacity in human lymphocytes. Compared to unscheduled DNA synthesis, which has been used in some clinical investigations, the CAT assay is considered more objective, quantitative, and applicable to population studies. Findings suggest that the paradigm of deficient DNA repair vs skin cancer seen in xeroderma pigmentosum is applicable to the general population, suggesting that DNA repair capacity may serve as a useful biomarker for cancer susceptibility.