Emerging Therapeutic Options for Breast Cancer Chemotherapy During Pregnancy

Background: Breast cancer is the commonest solid tumor observed during pregnancy. Anthracycline-based chemotherapy is feasible during the 2nd and 3rd trimesters of pregnancy, but few data are available on recent and highly active drugs taxanes, vinorelbine and anti-HER-2 agents in this setting.

Patients And Methods: We carried out a comprehensive review of reports documenting the use of taxanes, vinorelbine, trastuzumab and lapatinib during pregnancy in the English literature, in order to evaluate their safety profile in pregnant patients.

Results: Twenty-four pregnancies are described, in which no grade 3-4 maternal toxicity nor malformation in the offspring was reported. Whereas only one report studied the pharmacokinetics of paclitaxel (Taxol) during pregnancy, several preclinical reports indicate that the placental P-glycoprotein could prevent the transplacental transfer of taxanes and vinorelbine. The use of trastuzumab was associated with the occurrence of anhydramnios in three of six cases.

Conclusion: The administration of recent drugs taxanes and vinorelbine seems feasible during the 2nd and 3rd trimesters of pregnancy, with a favorable toxicity profile. In contrast, anti-HER-2 agents may obscure the normal development of the fetal kidney, and should be avoided during pregnancy.