Whole body MRI for systemic staging of breast cancer in pregnant women

When breast cancer is diagnosed during pregnancy, treatment should be as close; as possible to what is used in non-pregnant patients. This requires accurate local and systemic staging: ultrasound (US) is used for local staging and allows adequate evaluation of the liver and pelvis, but chest and bones cannot be explored and imaging techniques involving exposure to ionizing radiation would be needed. However, since imaging techniques involving ionizing radiation and the use of radionuclides should be limited, whole body magnetic resonance imaging (WB-MRI) without administration of contrast agent represents a very interesting alternative, but limited data is available. In this paper we describe the obstetrical and oncological outcome of 14 patients in whom breast cancer was diagnosed during the second or third trimester of pregnancy and that were staged using WB-MRI. Median age of the patient at diagnosis was 35 years (range 20-36), median gestational age at MRI was 30 weeks (range 13-32) and median age at delivery was 38 weeks (range 32-38). At birth, one new-born presented respiratory distress syndrome and one jaundice. We conclude that diffusion-weighted MRI is feasible accurate and safe for the mother and for the foetus. It may represent the staging technique of choice in pregnant women diagnosed with breast cancer after the first trimester of pregnancy.