Abstract

Whilst primary breast cancer affects 1 in 3000 pregnancies, metastatic breast cancer during pregnancy is extremely rare, with only a few cases being highlighted in the literature. Bone is the most common site of recurrence. This incidence is likely to increase as more women choose to delay child bearing.

This case describes a 42 year-old primigravida diagnosed with primary invasive ductal carcinoma in 2004. Her initial treatment included wide local excision with adjuvant radiotherapy and hormonal modulation. She underwent embryo cytopreservation prior to radiotherapy. In 2009 therapy was discontinued as she was considered disease free. In March 2010, following successful IVF treatment, she conceived monochorionic-diamniotic twins. Her pregnancy proceeded uneventfully until 13 weeks gestation, when she sustained a pathological fracture of her left femur. MRI imaging subsequently revealed multiple metastatic bone lesions.

After extensive discussion and counseling, the patient decided to continue with the pregnancy whilst commencing chemotherapy. Weekly epirubicin was started, together with pharmacological thromboproprophylaxis. Serial fetal growth scans showed good growth velocity with no twin-to-twin transfusion. Following severe pneumonia at 34 weeks gestation, delivery by caesarean section was expedited. All did well, and 14 months later mum remains in remission.

Metastatic breast cancer identified in pregnancy is a challenging situation with ethical considerations. Management strategies should be discussed within a multidisciplinary setting. The evidence base for safe chemotherapy use, outside the first trimester, is growing, and this case adds to the literature. Prognosis has improved with modern therapies, with a survival benefit seemingly uncompromised by pregnancy.