Use of in vitro fertilization programs to preserve reproductive material in patients with breast cancer

Objective: This study aimed to refine methodologies for implementing assisted reproductive technologies (ART), specifically in vitro fertilization (IVF), to preserve reproductive material in patients diagnosed with breast cancer. A comparative analysis of various ovarian stimulation protocols was conducted along with an evaluation of the impact of incorporating aromatase inhibitors (AIs) or selective estrogen receptor modulators (SERMs) on folliculogenesis and oocyte yield.

Materials and methods: This study included 471 female patients, of whom 346 underwent IVF cycles for oocyte or embryo cryopreservation. Prior to initiating treatment, a comprehensive review of medical records provided by oncologists was conducted, detailing the oncological diagnosis, disease stage, and results of diagnostic imaging (CT, MRI, and PET-CT), as well as morphological and immunohistochemical analyses. Additionally, each patient received a consultation with an oncologist-mammologist on the day of enrollment, which included an evaluation of the patient’s reproductive health, ovarian reserve, and overall gynecological status. The data were integrated to develop a personalized treatment protocol.

Results: The mean age of patients seeking fertility preservation was 29.5 (6.8) years, with the majority (221/346 (63.9%)) being under 35 years of age. All patients exhibited preserved ovarian reserve at the time of enrollment. Of the 346 breast cancer patients, 133 (38.4%) initiated ovarian stimulation during the follicular phase using a conventional protocol, whereas 213 (61.6%) commenced stimulation in the luteal phase using a random-start protocol. This study demonstrated that treatment efficacy, as measured by the number of retrieved oocytes and mature oocytes, depended on the patient’s ovarian reserve and was independent of the menstrual cycle phase at which stimulation was initiated. The administration of letrozole at doses of 2.5 mg and 5 mg yielded comparable outcomes in oocyte retrieval; however, the 5 mg dose was associated with significantly lower preovulatory estradiol levels. In contrast, the inclusion of tamoxifen in gonadotropin-based stimulation protocols resulted in suboptimal outcomes, with a trend toward reduced oocyte yield and quality.

Conclusion: The implementation of IVF protocols in patients with breast cancer should be guided by a multidisciplinary approach that incorporates both oncological and reproductive parameters. The number of oocytes retrieved is primarily determined by the ovarian reserve and is unaffected by the timing of stimulation initiation during the menstrual cycle. Aromatase inhibitors are the preferred pharmacological agents for ovarian stimulation in this patient population, whereas the use of tamoxifen is associated with inferior outcomes, including higher preovulatory estradiol levels and reduced oocyte quantity and quality.