Exposure to cigarette smoking (CS) is a major risk factor for the development of lung cancer. CS is known to cause oxidative DNA damage and mutation of tumor-related genes, and these factors are involved in carcinogenesis. 8-Hydroxydeoxyguanosine (8-OHdG) is considered to be a reliable biomarker for oxidative DNA damage. Increased levels of 8-OHdG are associated with a number of pathological conditions, including cancer. There are no reports on the expression of 8-OHdG by immunohistochemistry in non-small cell lung cancer (NSCLC). We investigated the expression of 8-OHdG and p53 in 203 NSCLC tissues using immunohistochemistry and correlated it with clinicopathological features including smoking. The expression of 8-OHdG was observed in 83.3% of NSCLC. It was significantly correlated with a low T category, negative lymph node status, never-smoker, and longer overall survival (p < .05) by univariate analysis. But multivariate analysis revealed that 8-OHdG was not an independent prognostic factor for overall survival in NSCLC patients. The aberrant expression of p53 significantly correlated with smoking, male, squamous cell carcinoma, and Ki-67 positivity (p < .05). The expression of 8-OHdG was associated with good prognostic factors. It was positively correlated with never-smokers in NSCLC, suggesting that oxidative damage of DNA cannot be explained by smoking alone and may depend on complex control mechanisms.

Joon Young Song, M.D., Kyung Hwa Kim, M.D., Ja Hong Kuh, M.D., Tae Youn Kim, M.D., and Jong Hun Kim, M.D.. Korean J Thorac Cardiovasc Surg 2018;51:415-8. https://doi.org/10.5090/kjtcs.2018.51.6.415

Mi Kyung Lee, M.D., Joon Young Song, M.D., Tae Youn Kim, M.D., Jong Hun Kim, M.D., Jong Bum Choi, M.D., Ja Hong Kuh, M.D.. Korean J Thorac Cardiovasc Surg 2016;49:485-8. https://doi.org/10.5090/kjtcs.2016.49.6.485

Ja Hong Kuh, M.D., Joon Young Song, M.D., Tae Youn Kim, M.D., Jong Hun Kim, M.D., Jong Bum Choi, M.D.. Korean J Thorac Cardiovasc Surg 2017;50:171-6. https://doi.org/10.5090/kjtcs.2017.50.3.171