YO1 - Locally Advanced Breast Cancer Outcome During Second Trimester of Pregnancy

Case summary

A gravid 33-year-old female was diagnosed with locally advanced Invasive breast carcinoma, left; ER 10% positive, PR negative, HER-2 3+ at 22 weeks age of gestation (AOG). After a multidisciplinary meeting was held, the patient decided to continue with her pregnancy while receiving oncologic intervention until fetal viability which was determined to be at 29 weeks age of gestation to ensure availability and functional nursery facility. She received her 1st cycle of neoadjuvant cycle at 22 weeks AOG with standard dose of 5-FU, Doxorubicin and Cyclophosphamide. The 2nd cycle of chemotherapy was given without 5FU was administered at 25 weeks AOG. She successfully delivered via cesarean section to a preterm male, APGAR 9.9 at 29 weeks AOG.
2 weeks post-partum, 1st cycle of neoadjuvant Trastuzumab, Pertuzumab and Docetaxel were initiated. Anti her-2 drugs were not considered during the course of pregnancy due to risk of oligo or anhydramnios. However, after 3 cycles of anti Her-2 therapy and Docetaxel, disease progressed to contralateral right breast with increasing size of left breast mass as seen in PET CT and breast MRI. This was accompanied with left breast pain. She then underwent bilateral modified radical mastectomy. Genomic profiling was requested along for guidance of subsequent systemic options.
Thereafter she received T-DM1, Ado-Trastuzumab Emtansin concurrent with radiation therapy to the bilateral chest wall and reigonal lymph nodes. After three cyles of T-DM1 interim evaluation with PET CT scan revealed intracranial and calvarial metastases where she underwent stereotactic radiosurgery (SRS). At this time, result of molecular profile reported EGFR and ERBB2 amplification, Microsatellite stable. She then received Afatinib 20 mg tablet once daily in addition to T-DM1. However due to grade 1 diarrhea, grade 2 thrombocytopenia and grade 3 acneiform rashes, Afatinib was reduced to 20 mg once daily three times a week. She was able to complete 12 cycles of T-DM1 and 33 fractions of radiation therapy. She is likewise tolerating well the adjusted dosing of Afatinib without recurrence of adverse events. Patient is due for interim assessment 2-3 weeks after completion of T-DM1. Meanwhile, the baby remained to be healthy up to present.

Clinical trial identification

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