RESUMEN
Pregnancy-associated breast cancer is the most common malignancy during pregnancy with an expected rise in incidence. The belief in the need for termination of pregnancy and that chemotherapy is contra-indicated during pregnancy is challenged by recent evidence. Patients can consider breast-conserving surgery and sentinel lymph node biopsy with acceptably low fetal risk from radiation exposure. A range of chemotherapeutics is possible in the second trimester in terms of drug class and frequency. Hormonal therapy and monoclonal antibody therapy are contra-indicated during pregnancy and lactation. Fetal outcome after in-utero exposure to chemotherapy appears similar to that in a non-pregnant population. Future pregnancy, in most situations, does not appear to be contra-indicated but a multidisciplinary and patient-centred approach is recommended. Fertility preservation techniques are also being developed with reported success and consequent pregnancies.