A case of delivery of healthy infant in breast cancer patient incidentally treated with goserelin acetate and tamoxifen during pregnancy

In September 2000, a 32-year-old woman presented to our hospital with a right breast mass. In September 2000, she underwent pectoral muscle-preserving mastectomy for the treatment of right breast cancer. Pathologyy results revealed a mucinous carcinoma 27 × 20 × 18 mm in size accompanied by an extensive intraductal component. The tumor was staged as T2 N1M0 stage IIB and found to be estrogen receptor-positive, and 6 cycles of postoperative adjuvant chemotherapy consisting of 5-fluorouracil, epirubicin, and cyclophosphamide were carried out. Goserelin acetate plus tamoxifen was prescribed from April 2001 to March 2005. Since the patient received tamoxifen from April 2005 and eumenorrhea started in June 2006, goserelin acetate plus tamoxifen was started in August 2006. The patient was determined to be 25 weeks pregnant by abdominal ultrasonography in February 2007. This meant that she had been taking goserelin acetate plus tamoxifen for 6 months without realizing she was pregnant. She gave birth to a girl by cesarean section in May 2007. No abnormalities, including anomaly of the genitalia, were seen, and the subsequent growth of the infant was also satisfactory. We here report this case and a brief review of the literature.