Mitochondrial DNA mutation correlates with stage progression and prognosis in non‐small cell lung cancer

The optimal management of patients with non-small cell lung cancer (NSCLC) depends onthe accuracy of appropriate staging strategies. Thebest approach for clinical staging, especially theevaluation of lymph node metastasis, continuesto confound clinicians. A specific, less-invasivemethod to support preoperative stage evaluation isrequired. Recently, Fliss et al. [2000] reported a highfrequency of mitochondria DNA (mtDNA) mutationin NSCLC. MtDNA is preferentially modified bymany carcinogens and is repaired less efficientlycompared with that of nuclear DNA [Khrapko et al.,1997]. We speculated an association between mtDNAmutation and NSCLC exists and, therefore, se-quenced the mtDNA of tumor cells from NSCLCpatients.This study was reviewed and approved by theKagoshima University Faculty of Medicine Committeeon Human Research.We prospectively investigated 202 NSCLC patients(adenocarcinoma, 106; squamous cell carcinoma,86; bronchoalveolar carcinoma, 4; large cell carcino-ma, 6), including 119 men and 83 women whosemean age was 63.2