RESUMEN
Background: Metastatic breast cancer diagnosis is the most common malignancy in pregnancy and the incidence of it has been increasing among the pregnant women due to advancing maternal age within the populations. However, there are limited data about the use of trastuzumab during pregnancy with conflicting results.Case history: A 37-year-old pregnant female patient was admitted to our hospital with the metastatic breast cancer diagnosis. An MRI study showed metastatic solid masses in all lobes and segments of the patient's liver. Patient was treated with weekly docetaxel and trastuzumab regimen from 22 to 34 weeks and labored electively at the 35th gestational week. Antenatal follow-up of the fetus showed all normal ranges without any complications. An abdominal MRI following the labor revealed complete clearance of liver metastasis.Conclusions: Use of trastuzumab during pregnancy is debated due to the limited number of cases reported in the literature. This article gives a summary of the existing data where the outcome was a complete remission in disease with normal fetal development during pregnancy.