Huber M H, Hong W K
Department of Thoracic/Head & Neck Medical Oncology, University of Texas M.D. Anderson Cancer Center, Houston.
Curr Probl Cancer. 1994 Mar-Apr;18(2):81-140. doi: 10.1016/0147-0272(94)90009-4.
Head and neck cancer remains a common cause of mortality and morbidity in the United States and throughout the world. In spite of advances in the management of patients with advanced disease, overall survival in this group remains poor. Furthermore, although cancer mortality is lower in patients with early-stage disease, treatment results in significant morbidity, and these patients also face the risk of developing a second primary tumor. Chemoprevention is an innovative approach to decrease overall cancer morbidity and mortality using substances that are capable of preventing cancer progression. Head and neck cancer is an excellent model for chemoprevention, as its biology is consistent with the two concepts important for the development of chemoprevention strategies: field cancerization and multistep carcinogenesis. Several classes of compounds have been evaluated in chemoprevention trials. The most frequently studied agents, the retinoids, were found frequently to induce remissions in patients with oral leukoplakia. Furthermore, retinoids prevented progression to malignancy in one randomized maintenance study. Other agents, including beta-carotene and vitamin E, have been found also to have activity in the management of oral leukoplakia. However, the clinical role of chemopreventive agents in reducing cancer mortality remains to be defined. Two studies, one in head and neck cancer and one in lung cancer, have shown the ability of retinoids to prevent the development of second primary tumors. Current large randomized trials are defining the effectiveness of these agents in reducing the mortality of aerodigestive tract tumors in individuals at high risk.
头颈癌在美国乃至全世界仍然是导致死亡和发病的常见原因。尽管晚期疾病患者的治疗取得了进展，但该群体的总体生存率仍然很低。此外，尽管早期疾病患者的癌症死亡率较低，但治疗会导致显著的发病率，而且这些患者还面临发生第二原发性肿瘤的风险。化学预防是一种创新方法，使用能够预防癌症进展的物质来降低总体癌症发病率和死亡率。头颈癌是化学预防的一个极佳模型，因为其生物学特性与化学预防策略发展的两个重要概念一致：场癌化和多步骤致癌作用。几类化合物已在化学预防试验中进行了评估。研究最频繁的药物——维甲酸类药物，经常被发现可诱导口腔白斑患者病情缓解。此外，在一项随机维持研究中，维甲酸类药物可预防病情进展为恶性肿瘤。其他药物，包括β-胡萝卜素和维生素E，也已被发现对口腔白斑的治疗有作用。然而，化学预防药物在降低癌症死亡率方面的临床作用仍有待确定。两项研究，一项针对头颈癌，一项针对肺癌，已表明维甲酸类药物能够预防第二原发性肿瘤的发生。目前正在进行的大型随机试验正在确定这些药物在降低高危个体气消化道肿瘤死亡率方面的有效性。
