The serum estradiol/oocyte ratio in patients with breast cancer undergoing ovarian stimulation with letrozole and gonadotropins

Random start ovarian stimulation before gonadotoxic therapies in women with cancer: a systematic review and meta-analysis

The aim of this systematic review and meta-analysis was to quantify the effect of random start ovarian stimulation (RSOS) compared with conventional start ovarian stimulation (CSOS) in cancer patients before gonadotoxic treatment. The final analytical cohort encompassed 688 RSOS and 1076 CSOS cycles of cancer patients before gonadotoxic treatment. Eleven studies were identified by database searches of MEDLINE, Cochrane Library and cited references. The primary outcomes of interest were the number of oocytes and mature oocytes collected, the number of embryos cryopreserved and the metaphase II (MII)-antral follicle count (AFC) ratio. The studies were rated from medium to high quality (from 6 to 9) according to the Newcastle-Ottawa Quality Assessment Scale. The two protocols resulted in similar numbers of oocytes collected, MII oocytes, embryos available for cryopreservation and comparable MII-AFC and fertilization rates. The duration of ovarian stimulation was longer (standardized mean difference [SMD] 0.35, 95% CI 0.09 to 0.61; P = 0.009) and gonadotrophin consumption was higher (SMD 0.23, 95% CI 0.06 to 0.40; P = 0.009) in RSOS compared with CSOS. This systematic review and meta-analysis show that the duration of stimulation is longer, and the total gonadotrophin consumption is higher in cancer patients undergoing RSOS compared with those undergoing CSOS, with no significant effect on mature oocyte yield.

Impact of BRCA mutations and hormone receptor status on reproductive potential in breast cancer patients undergoing fertility preservation

OBJECTIVE

To identify whether the BRCA mutations and hormone receptor status affect the ovarian reserve and ovarian stimulation outcomes in breast cancer patients undergoing fertility preservation.

METHODS

A total of 117 women diagnosed with breast cancer who were referred to the fertility preservation clinics at Seoul National University Bundang Hospital and Seoul National University Hospital between September 2012 and July 2019 undergone ovarian stimulation for oocyte retrieval. Basal characteristics including age, BMI, basal AMH, basal FSH, and fertility preservation outcomes such as the number of retrieved oocytes and mature oocytes were compared retrospectively.

RESULTS

BRCA1 mutation was noted in 25 women, and BRCA2 mutation was observed in 35 women. Positive estrogen receptor status was noted in 87 women, and positive progesterone receptor status was noted in 69 women. HER2 was positive in 55 women, and 19 women were diagnosed with triple-negative breast cancers. The number of total oocytes retrieved was lower in patients with BRCA mutation (8.3 ± 5.4 vs. 15.3 ± 8.7, p = .002). The number of mature oocytes retrieved was also lower in BRCA carriers (4.7 ± 4.2 vs. 8.7 ± 7.9, p = .025). Triple-negative breast cancer (TNBC) patients were younger than non-TNBC patients (30.3 ± 4.8 vs. 33.9 ± 5.0, p = .007). The rate of mature oocyte rate was higher in TNBC patients (68.6%±20.6 vs. 52.5%±29.7, p = .037).

CONCLUSIONS

Our study demonstrated that BRCA carriers with breast cancer had comparable ovarian reserve to non-carriers but the response to ovarian stimulation was lower. We also observed that oocyte maturity was higher in TNBC patients, however age might be a confounding factor of this result.

Fertility preservation for women with breast cancer before chemotherapy: a systematic review and meta-analysis

The preservation of fertility in women of childbearing age with breast cancer is challenging since the time for ovarian stimulation is restricted and only a limited amount of oocytes can be retrieved before gonadotoxic therapies. The aim of this meta-analysis is to evaluate the fertility preservation outcomes after ovarian stimulation with various protocols in women with breast cancer. PubMed, Embase, and the Cochrane Library were searched. Studies comparing the outcomes of women with breast cancer receiving random-start ovarian stimulation or conventional protocol; single or double ovarian stimulation cycles; and coadministration of aromatase inhibitors or tamoxifen were included. Twenty-two studies were included. Random-start ovarian stimulation resulted in a comparable number of retrieved oocytes to the conventional protocol. Two ovarian stimulation cycles had significantly higher numbers of total retrieved oocytes than one cycle (mean difference: 7.91, 95% CI: 3.42-12.4). Coadministration of letrozole and tamoxifen showed similar results of retrieved oocytes to those without. A significantly lower peak serum estradiol level was observed in letrozole-based groups than in letrozole-free groups. In conclusion, our study indicated that implementing random-start protocols to shorten the duration of waiting for ovarian stimulation, applying two ovarian stimulation cycles, and coadministering letrozole can lead to more desirable outcomes.

Ovarian stimulation for fertility preservation in women with cancer: A systematic review and meta-analysis comparing random and conventional starts

OBJECTIVE

In female cancer patients anticipating chemotherapy or radiation, oocyte retrieval for fertility should be performed as efficiently as possible to avoid postponing cancer treatments. Our objective was to compare clinical outcomes among female cancer patients who underwent a conventional early follicular phase-start ovarian stimulation cycle and those who underwent a random-start ovarian stimulation cycle.

EVIDENCE REVIEW

A systematic review of the literature was performed in accordance with PRISMA guidelines. Medline, Embase.com, Scopus, Cochrane Library, and Clinicaltrials.gov databases were searched to identify all original research published in English through July 2020 on the topic of female cancer patients undergoing ovarian stimulation with a random or conventional start. Studies lacking a comparison group or including women who had already undergone chemotherapy at the time of ovarian stimulation were excluded. The primary author assessed all identified article titles and abstracts, and two independent reviewers assessed full-text articles and extracted data. A meta-analysis with a random-effects model was used to calculate weighted mean differences (WMDs) for outcomes of interest. The primary outcome was the number of mature (meiosis II) oocytes retrieved. Secondary outcomes included duration of stimulation, total dose of gonadotropins, total number of oocytes retrieved, fertilization rate, and number of embryos or zygotes cryopreserved.

RESULTS

A total of 446 articles were screened, and 9 full-text articles (all retrospective cohort or prospective observational) were included for review. Additionally, pooled primary retrospective data from two institutions were included. In total, data from 10 studies including 1653 women were reviewed. Five studies reported the number of embryos cryopreserved, and four reported fertilization rates. Random-start cycles were slightly longer (WMD 0.57 days, 95 % confidence interval [CI] 0.0-1.14 days) and used more total gonadotropins (WMD 248.8 international units, 95 % CI 57.24-440.40) than conventional-start cycles. However, there were no differences in number of mature oocytes retrieved (WMD 0.41 oocytes, 95 % CI -0.84-1.66), number of total oocytes retrieved (WMD 0.90 oocytes, 95 % CI -0.21-2.02), fertilization rates (WMD -0.12, 95 % CI -1.22-0.98), or number of embryos cryopreserved (WMD 0.12 embryos, 95 %CI -0.98-1.22) between random-start and conventional-start cycles. All outcomes except for the parameter "total oocytes retrieved" yielded an I² of over 50 %, indicating substantial heterogeneity between studies.

CONCLUSION(S)

Although random-start cycles may entail a longer duration of stimulation and use more total gonadotropins than conventional-start cycles, the absolute differences are small and likely do not significantly affect treatment costs. The similar numbers of mature oocytes retrieved, fertilization rates, and number of embryos cryopreserved in the two start-types suggest that they do not differ in any clinically important ways. Given that random-start cycles can be initiated quickly, they may help facilitate fertility preservation for cancer patients.

Controlled ovarian hyperstimulation for fertility preservation in women with breast cancer: Practical issues

In Korean women, a westernized lifestyle is associated with an increased risk of breast cancer. Fertility preservation has become an increasingly important issue for women with breast cancer, in accordance with substantial improvements in survival rate after cancer treatment. The methods of controlled ovarian hyperstimulation (COH) for fertility preservation in breast cancer patients have been modified to include aromatase inhibitors to reduce the potential harm associated with increased estradiol levels. Random-start COH and dual ovarian stimulation are feasible options to reduce the total duration of fertility preservation treatment and to efficiently collect oocytes or embryos. Using a gonadotropin-releasing hormone agonist as a trigger may improve cycle outcomes in breast cancer patients undergoing COH for fertility preservation. In young breast cancer patients with BRCA mutations, especially BRCA1 mutations, the possibility of diminished ovarian reserve may be considered, although further studies are necessary. Herein, we review the current literature on the practical issues surrounding COH for fertility preservation in women with breast cancer.

Aromatase Inhibitors for Ovarian Stimulation in Patients with Breast Cancer

BACKGROUND

Breast cancer is the most common malignancy diagnosed in women, and its treatment has a high probability of loss of fertility. Oocyte vitrification is the most commonly used technique to preserve fertility before starting oncological treatment. Aromatase inhibitors induce hypoestrogenemia while promoting the release of gonadotropins and constitute an alternative drug for ovarian stimulation in patients with breast cancer.

OBJECTIVE

In this mini-review, we update and describe the current status of aromatase inhibitor use in controlled ovarian stimulation for oocyte vitrification in patients with breast cancer.

RESULTS

Aromatase inhibitors are commonly used in combination with gonadotropins for ovarian stimulation in patients with breast cancer who preserve their fertility through oocyte vitrification. They achieve similar ovarian responses as conventional ovarian stimulation protocols in regards to the number of oocytes, and no additional complications after their use have been reported. Furthermore, aromatase inhibitors seem to be safe not only for offspring, as no more congenital defects occur in newborns from pregnancies achieved after their use, but also for the patients, as no more malignancy recurrence or increased mortality was found in cohort studies.

CONCLUSION

Aromatase inhibitors are elective drugs for ovarian stimulation in patients with breast cancer who decide to preserve their fertility through oocyte vitrification.