Vorherr H
Semin Perinatol. 1979 Jul;3(3):299-311.
In the past, numerous efforts have been made to define risk and protective factors of breast cancer. Among these, pregnancy and lactation have been extensively discussed in connection with breast cancer. Unfortunately, many of the reports on the protective effects of pregnancy and lactation are equivocal; caution needs to be exercised when interpreting the results of a single publication. Development of breast cancer is often preceded by the occurrence of preneoplastic mammary lesions, which may be the result of long-term exposure to estrogens and prolactin. Since endogenous estrogen levels regulate pituitary prolactin secretion to some extent, it has been postulated that a hormonal imbalance exists in early mammary carcinogenesis. Exogenous estrogens directly increase pituitary prolactin secretion. During gestation, greatly increased levels of endogenous sex steroids efficiently stimulate pituitary prolactin secretion; during lactation, the stimulus of suckling is responsible for hyperprolactinemia. However, most studies did not reveal a cause-effect relationship between prolactin levels and enhanced risk of breast cancer. At present, the role of pregnancy and lactation in the development and prognosis of breast cancer is not determined.
过去，人们为确定乳腺癌的风险因素和保护因素付出了诸多努力。其中，妊娠和哺乳与乳腺癌的关系已得到广泛讨论。遗憾的是，许多关于妊娠和哺乳保护作用的报告并不明确；在解读单一出版物的结果时需谨慎。乳腺癌的发生通常先于癌前乳腺病变，这可能是长期暴露于雌激素和催乳素的结果。由于内源性雌激素水平在一定程度上调节垂体催乳素分泌，因此推测在早期乳腺癌发生过程中存在激素失衡。外源性雌激素直接增加垂体催乳素分泌。在妊娠期，内源性性类固醇水平大幅升高可有效刺激垂体催乳素分泌；在哺乳期，哺乳刺激是高催乳素血症的原因。然而，大多数研究并未揭示催乳素水平与乳腺癌风险增加之间的因果关系。目前，妊娠和哺乳在乳腺癌发生发展及预后中的作用尚未确定。
