Chemoproevention of Breast Cancer by Tamoxifen: Risks and Opportunities

• Published in: Critical reviews in toxicology Vol. 30; no. 5; p. 571
• Main Authors: Smith, Lewis L, Brown, Karen, Carthew, Philip, Lim, Chang-Kee, Martin, Elizabeth A, Styles, Jerry, White, Ian NH
• Format: Journal Article
• Language: English
• Published: 01.01.2000
• ISSN: 1040-8444

Tamoxifen, an anitestrogen used in the adjuvant therapy of breast cancer in women, has been shown to increase the risk of endometrial cancer by 2 to 5 times. In this study, rats, but not mice, which were given long-term administration of tamoxifen developed hepatocellular cancers. This occurs through a metabolic activation of the drug which results in DNA damage of tissues and eventually leads to gene mutations. The results of the studies on the rats do not predict carcinogenicity in human livers or organs, say the authors, but they point out that it does indicate potential problems is assessing future generations of estrogen receptor modulators.