Bennett L Michelle, Davis Barbara J
Genetics of Cancer Group, Biology and Biotechnology Research Program, Lawrence Livermore National Laboratory, Livermore, California 94551, USA.
Environ Mol Mutagen. 2002;39(2-3):150-7. doi: 10.1002/em.10068.
Results from chemical carcinogenesis studies in rodents are useful to identify substances in our environment that may contribute to cancer development. The National Toxicology Program (NTP) was established in 1978 to coordinate research and testing of potential human carcinogens and to publish the Report on Carcinogens, which lists human carcinogens. The results for over 500 chemicals tested in the NTP 2-year bioassays have been published in Technical Reports and include data for chemical, agent, or complex mixture exposures. The bioassays have identified 42 chemicals that induce tumors in the rodent mammary gland. The physical and chemical characteristics of the carcinogens vary, but epoxides (including chemicals metabolized to epoxides) and nitro-containing compounds are well represented. The 9th Report on Carcinogens, issued in 2000, lists 21 of the 42 chemicals as human carcinogens including benzene, ethylene oxide, 1,3-butadiene, isoprene, chloroprene, C.I. basic red 9, and C.I. acid red 114. Ethylene oxide was associated with increased breast cancer risk in an epidemiologic study, whereas other listed chemicals, for which human data are available, display different target organ specificity. Bioassays other than those conducted by the NTP also provide information about rodent mammary gland carcinogens. Several carcinogen exposures are associated with breast tumor induction in both humans and rodents including radiation, diethylstilbestrol, and estrogens. These studies demonstrate that route, timing and frequency of exposure, and genetic factors contribute to the overall susceptibility to breast cancer development. More information is needed on the effects of chemicals to which humans are exposed and the manner by which they influence breast cancer risks.
啮齿动物化学致癌研究的结果有助于识别我们环境中可能导致癌症发生的物质。国家毒理学计划（NTP）成立于1978年，旨在协调对潜在人类致癌物的研究和测试，并发布《致癌物报告》，该报告列出了人类致癌物。在NTP的两年生物测定中测试的500多种化学物质的结果已发表在技术报告中，包括化学物质、制剂或复杂混合物暴露的数据。生物测定已确定42种化学物质可诱发啮齿动物乳腺肿瘤。致癌物的物理和化学特性各不相同，但环氧化物（包括代谢为环氧化物的化学物质）和含氮化合物占比很大。2000年发布的第9版《致癌物报告》将42种化学物质中的21种列为人类致癌物，包括苯、环氧乙烷、1,3 - 丁二烯、异戊二烯、氯丁二烯、碱性红9和酸性红114。在一项流行病学研究中，环氧乙烷与乳腺癌风险增加有关，而其他有人类数据的所列化学物质则表现出不同的靶器官特异性。除NTP进行的生物测定外，其他生物测定也提供了有关啮齿动物乳腺致癌物的信息。包括辐射、己烯雌酚和雌激素在内的几种致癌物暴露与人类和啮齿动物的乳腺肿瘤诱发有关。这些研究表明，暴露途径、时间和频率以及遗传因素会影响乳腺癌发生的总体易感性。需要更多关于人类接触的化学物质的影响及其影响乳腺癌风险方式的信息。
