DNA repair capacity correlates with standardized uptake values from ¹⁸F-fluorodeoxyglucose positron emission tomography/CT in patients with advanced non–small-cell lung cancer

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 (SUV_max) on¹⁸F-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 reactivation assay with SUV_max and their associations with overall survival (OS) time by hazards ratios calculated with a Cox proportional hazards regression model. Results: SUV_max 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, ΔSUV_max of primary tumor was not significantly associated with DRC (r = 0.005, P = 0.968). SUV_max of regional lymph nodes at diagnosis (r = −0.307, P = 0.0008) and after (chemo)radiation treatment (r = −0.329, P = 0.034) and SUV_max 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 SUV_max before treatment but not with ΔSUV_max after (chemo)radiation.