Effect of breast cancer prognostic factors on ovarian reserve and response in fertility preservation

RESEARCH QUESTION

Do breast cancer prognostic factors influence ovarian reserve and response to ovarian stimulation in the context of fertility preservation?

DESIGN

Observational, bicentric retrospective study of 352 women with breast cancer who underwent ovarian stimulation using a random start gonadotrophin releasing hormone antagonist protocol and vitrified oocytes between November 2015 and August 2022. Serum anti-Müllerian hormone (AMH) levels and antral follicle count (AFC) were measured. The number of oocytes recovered, maturation rate and follicular output rate (FORT) were analysed according to patients' characteristics and breast cancer prognostic factors.

RESULTS

Median age was 34 years (31.1-37.1). Median AFC and serum AMH level were 17 (12-26) follicles and 2 (1.2-3.4) ng/ml, respectively. After ovarian stimulation, 10.5 (6.0-16.0) oocytes were recovered, with eight (4-13) being mature. Mean oocyte maturation rate was 79% (62-92). Antral follicle count (>12) significantly affected the risk of recovering fewer than eight mature oocytes (P < 0.0001, multivariate analysis). Follicular responsiveness to FSH, assessed by the follicular output rate (FORT index) and number of oocytes recovered, were 31% (21-50) and 10.5% (6.0-16.0), respectively. FORT index and ovarian stimulation outcomes were not influenced by breast cancer prognostic factors.

CONCLUSION

Breast cancer prognostic factors do not influence ovarian reserve markers or response to ovarian stimulation in fertility preservation. Therefore, tumour grade, triple-negative status, HER2 overexpression and high Ki67 should not alter the fertility-preservation strategy when considering ovarian stimulation for oocyte vitrification.

New Insights on In Vitro Maturation of Oocytes for Fertility Preservation

In the last decade, the evolution of oncofertility has sparked a resurgence of interest in in vitro maturation (IVM) due to its suitability in certain oncological scenarios where controlled ovarian hyperstimulation may not be feasible. The retrieval of immature cumulus-oocyte complexes from small antral follicles, regardless of the menstrual cycle phase, presents a swift opportunity to vitrify mature oocytes or embryos post-IVM in urgent situations or when stimulation is not advisable. Harvesting immature cumulus-oocyte complexes and immature oocytes can be achieved transvaginally or directly in the laboratory from extracorporeal ovarian tissue. Although IVM has transitioned from an experimental status due to safety validations, it relies on the intricate process of oocyte maturation. Despite successful live births resulting from IVM in fertility preservation contexts, the comparatively lower developmental competence of in vitro matured oocytes highlights the necessity to enhance IVM culture systems. Recent advancements in IVM systems hold promise in bolstering oocyte competence post-IVM, thereby narrowing the gap between IVM and outcomes from ovarian stimulation. Additionally, for optimizing the chances of conception in cancer survivors, the combination of IVM and ovarian tissue cryopreservation stands as the favored choice when ovarian stimulation is unfeasible.

Ovarian stimulation response and fertility outcomes in patients with breast cancer across different stages, grades, and hormone receptor status for fertility preservation

BACKGROUND

This study aimed to explore the potential impact of stage, grade, and hormone receptor profile on ovarian stimulation response and fertility preservation outcomes.

METHODS

This retrospective cohort study evaluated data from breast cancer patients who underwent fertility preservation at a tertiary medical center between 2014 and 2022. The outcomes of women with low-stage cancer (stages I and II) were compared with those of women with high-stage disease (stages III and IV or lymph node metastasis). Similarly, we compared those with low-grade (grades 1 and 2) and high-grade (grade 3) malignancies. In addition, we compared different hormone statuses of breast cancer (1) estrogen receptor (ER) positive vs. ER-negative and (2) triple-negative breast cancer (TNBC) vs. non-TNBC. The primary outcome measured was the number of mature oocytes, while the secondary outcomes included the numbers of total oocytes retrieved, peak estradiol levels, and subsequent fertility preservation outcomes.

RESULTS

A total of 47 patients were included. Patients with high-grade tumors had a comparable number of mature oocytes (8 vs. 10, p = 0.08) compared to patients with low grade cancers. The stage-based analysis revealed a similar number of mature oocytes (8 vs. 10, p = 0.33) between high/low stage patients. In the hormone receptor-based analysis, no differences were seen in mature oocytes collected between the ER-positive/ER-negative group (9 vs. 9, p = 0.87) and the TNBC/non-TNBC group (11 vs. 9, p = 0.13). The utilization rate was 27.6% (13/47).

CONCLUSION

Our study showed similar ovarian stimulation response and fertility preservation outcomes among breast cancer patients with different prognostic factors.

Impact of oxygen tension during in vitro maturation: a sibling-oocyte prospective double-blinded study

OBJECTIVE

To determine whether oxygen (O2) tension (20% vs. 5%) has an impact on oocyte maturation rates and morphology during in vitro maturation (IVM).

DESIGN

A prospective, observational, monocentric, sibling-oocyte study.

SETTING

University Hospital.

PATIENTS

A total of 143 patients who underwent IVM for fertility preservation purposes from November 2016 to April 2021 were analyzed. Patients were included when ≥2 cumulus-oocyte complexes (COCs) were retrieved. The cohort of COCs obtained for each patient was randomly split into two groups: group 20% O2 and group 5% O2.

INTERVENTION

Cumulus-oocyte complexes were incubated for 48 hours either under 5% O2 or 20% O2. After 24 and 48 hours of culture, every oocyte was assessed for maturity and morphology, to estimate oocyte quality. Morphology was evaluated considering six parameters (shape, size, ooplasm, perivitelline space, zona pellucida, and polar body characteristics), giving a total oocyte score ranging from -6 to +6.

MAIN OUTCOME MEASURES

Maturation rates and total oocyte scores were compared using paired-sample analysis between group 20% O2 and group 5% O2.

RESULTS

Patient median age was 31.4 [28.1-35.2] years-old. The mean serum antimüllerian hormone levels and antral follicle count were 3.2 ± 2.3 ng/mL and 27.2 ± 16.0 follicles, respectively. A mean of 10.7 COCs per cycle were retrieved, leading to 6.1 ± 2.4 metaphase II oocytes vitrified (total maturation rate = 57.3%; 991 metaphase II oocytes/1,728 COCs). A total of 864 COCs were included in each group. Oocyte maturation rates were not different between the two groups (group 20% O2: 56.82% vs. group 5% O2: 57.87%, respectively). Regarding oocyte morphology, the mean total oocyte score was significantly higher in group 5% O2 compared with group 20% O2 (3.44 ± 1.26 vs. 3.16 ± 1.32, P=.014).

CONCLUSION

As culture under low O2 tension (5% O2) improves oocyte morphology IVM, our results suggest that culture under hypoxia should be standardized. Additional studies are warranted to assess the impact of O2 tension on oocyte maturation and the benefit of IVM under low O2 tension for embryo culture after utilization of frozen material.

Controlled ovarian hyperstimulation in breast cancer patients: Does oestrogen receptor status make a difference?

BACKGROUND

The presence of different breast cancer receptor status may impact ovarian stimulation outcomes.

AIM

To study the association between oestrogen receptor (ER) status in breast cancer patients and fertility preservation outcomes in a major tertiary referral centre.

MATERIALS AND METHODS

Women who underwent fertility preservation following the diagnosis of breast cancer from 2008 to 2018 were included in the study. Patient age, ovarian stimulation parameters and laboratory outcomes were recorded and compared between the ER positive and negative groups. The primary outcome was total number of oocytes frozen. Secondary outcomes included total number of oocytes collected, mature oocytes, and embryos frozen.

RESULTS

The women included in the study (n = 214) were analysed in the following groups based on their fertility preservation method: oocyte freezing (n = 131), embryo freezing (n = 70), and both embryo and oocyte freezing (n = 13). There was an increase in the mean (but not mature) number of oocytes frozen (12.4 and 9.2, P-value = 0.03) favouring the ER positive group, even though the women in this group were older (35.0 and 33.4, P-value of 0.03). There is no difference in the starting follicle-stimulating hormone dose, duration of stimulation, mature oocytes collected, and embryos frozen in both groups.

CONCLUSION

Patients with ER positive breast cancer may have more positive ovarian stimulation outcomes.