Tamoxifen as systemic treatment of advanced breast cancer during pregnancy--case report and literature review.

BACKGROUND: When patients with metastatic breast cancer become pregnant, management is complicated by the potential harms of drug treatment to the fetus and by the potential effects of the pregnancy on the cancer. Chemotherapy is considered optimal systemic anti-cancer therapy from the second trimester, while tamoxifen has been considered inappropriate due to concerns over possible teratogenesis and lack of efficacy. CASE: We report a patient who became pregnant concurrent with the identification of metastatic breast cancer and who elected to continue her pregnancy with tamoxifen as sole systemic anti-cancer therapy. The pregnancy was difficult, but a normal child was delivered and the mother responded to subsequent hormone manipulation. The putative teratogenic effects of tamoxifen and the mechanisms underlying tamoxifen resistance in this setting are discussed.
CONCLUSIONS: The use of tamoxifen in pregnancy is complex, but is not necessarily associated with fetal harm and may be considered a therapeutic option in selected cases. Copyright 2001 Academic Press.