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死亡统计表明目前癌瘤是儿童主要死因之一.儿童癌瘤日趋常见,普遍认为癌瘤在体内形成需数年至数十年的潜伏期,提示癌瘤有可能在生命的早期或在母体子宫内就已发生.许多化学致癌物也是致畸物,可通过胎盘屏障引起胚胎死亡或/和使胎儿发生畸形和肿瘤.动物实验表明,胎儿组织对多数致癌物的生物学效应比成年动物强.因此,经胎盘致癌这个问题不仅在实验肿瘤学和肿瘤防治领域,而且在优生学、孕期卫生以及在药物、食品添加物和环境污染物安全性评价方面已引起广泛重视.
Death statistics show that cancer is one of the major causes of death in children.Chronic cancer is increasingly common, it is generally believed that cancer in the body to form a latent period of several years to decades, suggesting that cancer may be early in life or in the mother’s womb Has occurred.Many chemical carcinogens are also teratogenic agents that can cause embryonic death and / or deformities and tumors in the fetus through the placental barrier.Experimental studies have shown that the biological effects of fetal tissue on most carcinogens are greater than in adult animals. , The problem of carcinogenesis through the placenta not only in the field of experimental oncology and cancer prevention and control, but also in eugenics, health during pregnancy, as well as in the safety evaluation of drugs, food additives and environmental pollutants has attracted widespread attention.