Endocrine Abstracts

Introduction: Breast cancer is the second most common neoplasm in women. Hormonal replacement therapy and combined hormonal contraception are established extrinsic hormonal risk factors for breast cancer. Therefore, the increase in the prevalence of infertility and the use of assisted conception techniques have raised questions regarding the potential risk of hormone-dependent neoplasms. We report the case of a woman diagnosed with bilateral metastasized breast cancer soon after ovarian stimulation.

Case report: A 42-year-old woman with a 3-month history of worsening mechanical back pain visited the medical clinic with a dorso-lumbar CT scan report showing multiple vertebral lytic lesions (D3, D6, D10, L1, L2, L3, and L4) and two vertebral compression fractures (D6 and L5). She suffered from infertility and had just finished the third cycle of ovarian stimulation for oocyte collection. Before treatment, she underwent bilateral mammography and breast ultrasound, classified as BI-RADS 3, with no further follow-up. The patient had no family history of cancer. She was admitted for diagnostic assessment, which revealed stage IV bilateral breast cancer with multiple bone metastases (vertebrae, sternum, ribs, and the right femur). In the right breast, mass biopsy showed luminal A like/Her2 2+ FISH negative cT1 cN1 (metastases in the right axillary lymph nodes). In the left breast, mass biopsy showed luminal B like/Her2 2+ FISH positive cT1mf cN0. Vertebral biopsy of L5 revealed metastasis of the left breast cancer. Next-generation sequencing for the diagnosis of hereditary breast and ovarian cancer syndrome was unremarkable. She was referred to the oncology clinic and started on docetaxel, pertuzumab, trastuzumab, zoledronate, and radiotherapy. Follow-up showed stable disease nine months after the initiation of cancer treatment.

Conclusions: Current evidence indicates that ovarian stimulation does not appear to increase the risk of breast cancer. However, treatment with gonadotropins and estradiol is contraindicated in patients with this clinical entity. Thus, in this case report, ovarian stimulation may have enhanced the aggressive behavior of breast cancer, which was most likely present at the beginning of the infertility treatment. Hence, we raise the possibility of a distinct screening for breast cancer before, during, and after ovarian stimulation, whose consequences are still unpredictable regarding the risk and natural history of breast cancer.