Department of Radiotherapy, Maulana Azad Medical College, New Delhi 110002, India.
Cancer Biomark. 2009;5(6):253-60. doi: 10.3233/CBM-2009-0110.
Cancer of posterior one-third of tongue is seen in 0.43% of total world population. Worldwide, cancer of tongue constitutes 5% of the total cancer incidence. Squamous cell cancer of head and neck is the most common cancer encountered in India. Oxidative stress is potentially harmful to cells and ROS are involved in multistage carcinogenesis, in initiation and promotion. Moreover, the extent of ROS-induced oxidative damage can be exacerbated by decreased efficiency of antioxidant defense mechanisms. The aim of this study was to assess the alterations in the circulating lipid peroxide, antioxidant components and the activities of defense enzymes in patients with cancer of posterior one-third of tongue, with respect to healthy controls in the Indian population.
60 patients with newly diagnosed, histologically proven cases of locally advanced squamous cell carcinoma (Stage III-IVa) of posterior one-third of tongue were recruited into the study. 60 healthy controls, without history or laboratory evidence of malignancy and inflammatory disorder, were also included in the study, after obtaining informed consent. Single blood samples were taken from patients, before start of therapy and controls. Lipid peroxides, conjugated dienes, reduced glutathione (GSH), vitamin C and E were estimated using standard methods. Glutathione peroxidase (GPx) and superoxide dismutase (SOD) were assayed using commercially available kits from Randox, UK.
The pre-treatment levels of plasma lipid peroxide and conjugated dienes were significantly elevated in patients with carcinoma of posterior one-third of tongue, as compared with controls (p=0.001). Significantly lowered levels of GSH, GPx, SOD and antioxidant vitamins were observed in cancer patients, when compared to control subjects (p=0.001). Pearson's correlation analysis showed a highly statistitically significant negative correlation between pro-oxidant and anti-oxidant levels in patients.
Increased levels of oxidative stress markers and decreased levels of antioxidants in carcinoma of posterior one-third of tongue suggest that oxidative stress markers play a significant role in the pathophysiology of tongue cancer. These findings may suggest possible use of antioxidant supplementation as prophylactic agents for prevention and treatment of tongue cancer. A larger patient cohort for therapeutic response after treatment with a longer follow-up period studies might yield more significant data on their probable use as predictors of chemoradiosensitivity of cancer of tongue.
舌后三分之一的癌症在全球总人口中占 0.43%。在世界范围内，舌癌占癌症总发病率的 5%。头颈部鳞状细胞癌是印度最常见的癌症。氧化应激对细胞是潜在有害的，ROS 参与多阶段致癌作用，包括启动和促进。此外，抗氧化防御机制效率降低会加剧 ROS 诱导的氧化损伤程度。本研究旨在评估舌后三分之一癌症患者与健康对照组相比，循环脂质过氧化物、抗氧化成分和防御酶活性的变化，以评估印度人群中舌癌的变化。
纳入 60 例新诊断为局部晚期舌后三分之一鳞状细胞癌（III-IVa 期）的患者。60 例无恶性肿瘤和炎症性疾病病史或实验室证据的健康对照者在知情同意后也纳入研究。在开始治疗前，从患者和对照者中抽取单一血样。采用标准方法测定脂质过氧化物、共轭二烯、还原型谷胱甘肽（GSH）、维生素 C 和 E。使用来自英国 Randox 的市售试剂盒测定谷胱甘肽过氧化物酶（GPx）和超氧化物歧化酶（SOD）。
与对照组相比，舌后三分之一癌患者治疗前血浆脂质过氧化物和共轭二烯水平显著升高（p=0.001）。与对照组相比，癌症患者的 GSH、GPx、SOD 和抗氧化维生素水平明显降低（p=0.001）。Pearson 相关分析显示，患者的促氧化剂和抗氧化剂水平之间存在高度统计学显著的负相关。
舌后三分之一癌中氧化应激标志物水平升高和抗氧化剂水平降低表明氧化应激标志物在舌癌的病理生理学中起重要作用。这些发现可能表明抗氧化剂补充可能作为预防和治疗舌癌的预防剂。更大的患者队列进行治疗后治疗反应的研究，并进行更长的随访期研究，可能会产生更多关于其作为舌癌化学放射敏感性预测因子的可能用途的更显著数据。
