Stage 0 ER-positive DCIS: mastectomy without adjuvant therapy, followed by successful pregnancy

What happened, in summary

This patient began infertility treatment in 2009 at age 44. Because her partner was 9 years older and sperm availability was limited, cryopreserved sperm was used for intracytoplasmic sperm injection. Over 6 years, she underwent 21 oocyte retrieval cycles and 7 frozen-thawed embryo transfer cycles, using an oocyte and embryo banking strategy to build enough embryos for repeated attempts. In September 2012, at age 47, she was diagnosed with ductal carcinoma in situ of the left breast. On October 31, 2012, she had a left subcutaneous mastectomy, sentinel lymph node biopsy, and immediate reconstruction. Pathology showed a 12-mm DCIS lesion that was ER-positive, PgR-positive, HER2-negative, nuclear grade 2, and comedo type, with negative margins and no lymph node involvement. After surgery, she did not receive chemotherapy, radiotherapy, tamoxifen, or an aromatase inhibitor. That treatment plan allowed her to resume assisted reproductive treatment without the delays that adjuvant therapy might have created. After cancer surgery, she had 6 unsuccessful frozen embryo transfers. In February 2015, 2 embryos cryopreserved in 2010, when she was 45, were thawed and transferred in a hormone-replacement cycle. Her serum hCG was 446.6 mIU/mL, confirming pregnancy. The pregnancy was uneventful despite advanced maternal age and first pregnancy, and the case included close obstetric monitoring because of those risk factors and prior breast cancer treatment history. She was monitored for complications such as gestational hypertension and diabetes, but none developed. At 38 weeks and 5 days, she delivered a healthy male infant by elective cesarean section.