Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Tata Memorial Centre (TMC), Kharghar, Navi-Mumbai-410 208, India.
J Clin Biochem Nutr. 2007 Mar;40(2):82-91. doi: 10.3164/jcbn.40.82.
Cancer chemoprevention is fast becoming a lucrative approach for controlling cancer. Carcinogenesis being a complex multi-step, multi-factorial process, a number of chemopreventive interventions can be employed. These strategies are generally directed against two broad events of carcinogenesis viz., initiation and promotion/progression. Anti-initiation interventions principally involve inhibition of carcinogen activation, scavenging of free radicals and reactive carcinogen metabolites along with enhanced detoxification of carcinogens by modulating cellular metabolism. Anti-promotion strategies involve attenuation of enhanced cellular proliferation along with induction of cellular apoptosis and differentiation. Dietary agents or herbal anti-oxidants due to low toxicity and relative safety are promising chemopreventive agents. These agents after emerging successful through a series of in vitro and in vivo assays enter clinical trials. Many dietary compounds have emerged as promising chemopreventive agents in empirical experiments. However, in clinical trials these compounds have met with limited success. This emphasizes the need for further detailed research on the mechanisms of observed chemoprevention and choice, dose, duration and bioavailability of chemopreventive agent used. Complex issues such as choice and nutritional status of target population, genetic variation, gene-environment interactions and relevance of biomarkers analyzed also warrant further research and analyses.
癌症化学预防正迅速成为控制癌症的一种有利可图的方法。癌症发生是一个复杂的多步骤、多因素的过程，可以采用多种化学预防干预措施。这些策略通常针对癌症发生的两个广泛事件，即启动和促进/进展。抗启动干预主要涉及抑制致癌物的激活、清除自由基和反应性致癌代谢物，以及通过调节细胞代谢增强致癌物的解毒。抗促进策略涉及减弱增强的细胞增殖，同时诱导细胞凋亡和分化。由于毒性低和相对安全性，膳食剂或草药抗氧化剂是有前途的化学预防剂。这些药物在一系列体外和体内试验中成功后，进入临床试验。许多膳食化合物在经验性实验中已成为有前途的化学预防剂。然而，在临床试验中，这些化合物的效果有限。这强调了需要进一步详细研究观察到的化学预防的机制以及化学预防剂的选择、剂量、持续时间和生物利用度。还需要进一步研究和分析复杂问题，如目标人群的选择和营养状况、遗传变异、基因-环境相互作用以及分析的生物标志物的相关性。
