Treatment of pregnancy-associated breast cancer

In primary breast cancer three therapeutic components-cytotoxic, endocrine and targeted antibody therapy-have led to a significant reduction in breast cancer mortality. In pregnancy associated breast cancer the right therapeutic choice is still under discussion while incidence is increasing. With an incidence of 1/3,000 to 1/10,000 pregnancies, pregnancy-associated breast cancer is the most common solid tumor in pregnancy after cervical carcinoma.

This article reviews the evidence base for the use of various treatment modalities in patients with pregnancy-associated breast cancer.

Medline review, searching for articles including years 2000 through 2008 was performed. Search was conducted for the terms "pregnancy" and "breast cancer". Cross references up to the second level were taken into account if of interest for this review.

Loco-regional therapy of pregnancy-associated breast cancer follows the general guidelines for breast cancer therapy in principle. Radiation of the breast and/or chest wall is usually not performed during pregnancy. Chemotherapy is indicated for the majority of patients with pregnancy-associated breast cancer. After the first trimester, anthracycline-based chemotherapy is regarded as the treatment standard in pregnancy. Folate antagonists such as methotrexate are strictly contraindicated as they are the main cause of fetal malformations. Adjuvant endocrine therapy with anti-estrogens during pregnancy is contraindicated. Data on targeted biological treatment, particularly for HER2/neu positive tumors during pregnancy are scarce and this treatment should be postponed until after delivery.

This article summarizes the special features of the diagnosis and primary therapy of pregnancy-associated breast cancer with particular emphasis on cytotoxic therapy.