Objective: The DNA repair capacity (DRC) of tumor cells is an important contributor to resistance to radiation and platinum-based drugs. Because DRC may be affected by tumor cell metabolism, we measured DRC in lymphocytes from patients with non-small-cell lung cancer (NSCLC) and compared the findings with the maximum standardized uptake value (SUVmax) on 18 F-fluorodeoxyglucose positron emission tomography (FDG PET) after (chemo)radiation therapy. Methods: This study included 151 patients with stage IA-IV NSCLC who had FDG PET at a single institution and donated blood samples before chemotherapy. We assessed the correlation of DRC, measured in peripheral T lymphocytes by a host-cell reac-tivation assay with SUVmax and their associations with overall survival (OS) time by hazards ratios calculated with a Cox pro-portional hazards regression model. Results: SUVmax of the primary tumor at diagnosis was inversely associated with lymphocyte DRC (r＝－0.175, P＝0.032), particularly among patients with advanced disease (r ＝ －0.218, P ＝ 0.015). However, △SUVmax of primary tumor was not significantly associated with DRC (r＝0.005, P＝0.968). SUVmax of regional lymph nodes at diagnosis (r＝－0.307, P＝0.0008) and after (chemo)radiation treatment (r＝－0.329, P＝0.034) and SUVmax of the primary tumor after (chemo)radiation treatment (r＝－0.253, P＝0.045) were also inversely associated with OS time. Conclusion: DRC was inversely associated with primary tumor SUVmax before treatment but not with △SUVmax after (chemo)radiation.

Objective: The DNA repair capacity (DRC) of tumor cells is an important contributor to resistance to radiation and platinum-based drugs. Because DRC may be affected by tumor cell metabolism, we measured DRC in lymphocytes from patients with non-small-cell lung cancer (NSCLC) and compared the findings with the maximum standardized uptake value (SUVmax) on 18 F-fluorodeoxyglucose positron emission tomography (FDG PET) after (chemo)radiation therapy. Methods: This study included 151 patients with stage IA-IV NSCLC who had FDG PET at a single institution and donated blood samples before chemotherapy. We assessed the correlation of DRC, measured in peripheral T lymphocytes by a host-cell reac-tivation assay with SUVmax and their associations with overall survival (OS) time by hazards ratios calculated with a Cox pro-portional hazards regression model. Results: SUVmax of the primary tumor at diagnosis was inversely associated with lymphocyte DRC (r＝－0.175, P＝0.032), particularly among patients with advanced disease (r ＝ －0.218, P ＝ 0.015). However, △SUVmax of primary tumor was not significantly associated with DRC (r＝0.005, P＝0.968). SUVmax of regional lymph nodes at diagnosis (r＝－0.307, P＝0.0008) and after (chemo)radiation treatment (r＝－0.329, P＝0.034) and SUVmax of the primary tumor after (chemo)radiation treatment (r＝－0.253, P＝0.045) were also inversely associated with OS time. Conclusion: DRC was inversely associated with primary tumor SUVmax before treatment but not with △SUVmax after (chemo)radiation.