Comparison of the effects of letrozole and cabergoline on vascular permeability, ovarian diameter, ovarian tissue VEGF levels, and blood PEDF levels, in a rat model of ovarian hyperstimulation syndrome

Two cases of polycystic ovary syndrome with onset of severe ovarian hyperstimulation syndrome following controlled ovarian stimulation with aromatase inhibitors for fertility preservation before breast cancer treatment

OBJECTIVE

The risks of ovarian hyperstimulation syndrome (OHSS) involve high estrogen (E₂) levels. We report two breast cancer patients with polycystic ovarian syndrome who underwent fertility preservation and had severe OHSS; their E₂ levels were lowered using aromatase inhibitors (AI).

CASE REPORTS

A 36-year-old woman underwent controlled ovarian stimulation (COS) with AI and cryopreserved 10 blastocysts. She was hospitalized with OHSS (E₂ = 139.1 pg/mL). She improved with infusion alone. A 31-year-old woman underwent COS with AI and cryopreserved 8 blastocysts. She was hospitalized for OHSS (E₂: 429 pg/mL). Her vascular endothelial growth factor (VEGF) levels were high (62 pg/mL) at 8 days after the procedure. She needed hospitalization for 9 days. The planned adjuvant therapy was delayed for a week in both cases.

CONCLUSION

Elevated VEGF levels should be considered as a risk factor of OHSS even if E₂ levels are low with AI treatment.

Letrozole for Female Infertility

Letrozole, an aromatase inhibitor that blocks estrogen synthesis by inhibiting the final step of the estrogen biosynthetic pathway, has been used in the applications of a wide range of infertility settings. It has been more than 20 years since the initial clinical trial of letrozole for ovulation induction. In light of the accumulating clinical and basic evidence, the efficacy and safety of letrozole have been identified. This mini review focuses on our current knowledge of the applications and mechanisms of letrozole for female infertility and various questions are put forward about how letrozole could be more effectively used.

Oxytocin and cabergoline alleviate ovarian hyperstimulation syndrome (OHSS) by suppressing vascular endothelial growth factor (VEGF) in an experimental model

PURPOSE

Ovarian hyperstimulation syndrome (OHSS) is a life-threatening complication of ovarian stimulation in reproductive medicine. Here, we aimed to investigate the role of oxytocin (OT) and cabergoline in the prevention and alleviation of the OHSS in an animal model.

METHODS

Thirty-five female immature Wistar rats were randomly assigned to five groups. The control group (n = 7) received saline only for five consecutive days. Remaining twenty-eight rats received 10 IU of pregnant mare serum gonadotropin (PMSG) followed by 30 IU of human chorionic gonadotropin (hCG) to induce OHSS. Group 2 (n = 7) was managed with no additional intervention after the induction of OHSS. Group 3 (n = 7) received 100 μg/kg cabergoline 2 h before the PMSG injection for four consecutive days and 2 h before the hCG injection on the fifth day. Group 4 (n = 7) and group 5 (n = 7) received 80 μg/kg and 160 μg/kg OT after induction of OHSS, respectively. Oxytocin was administered 2 h before the PMSG injection for four consecutive days and 2 h before the hCG injection on the fifth day. Body and ovary weight, vascular permeability (VP), VEGF expression in the ovaries, and levels of VEGF in the peritoneal fluids were examined in all animals.

RESULTS

Cabergoline and OT reduced body weight, ovary weight, and VP compared to that of the OHSS group (p < 0.05). VEGF expressions in ovaries and peritoneal VEGF levels were decreased in cabergoline and OT groups compared to that of the OHSS groups (p < 0.001 for cabergoline and OT-80 μg/kg; p < 0.00001 for OT-160 μg/kg). However, there was no statistically significant difference in these parameters between the OT and cabergoline groups.

CONCLUSION

Both OT and cabergoline were active in the alleviation of OHSS through suppression of VEGF and VP. Overall, we conclude that OT is effective for downregulation for VEGF and improvement in vascular permeability in OHSS.

Oocyte cryopreservation in the setting of a vascular endothelial growth factor (VEGF)-producing paraneoplastic syndrome: a case report and review of literature

BACKGROUND

Many reproductive aged women with new oncologic diagnoses choose to undergo emergency oocyte or embryo cryopreservation prior to initiating potentially gonadal toxic oncologic therapies. Ovarian hyperstimulation syndrome (OHSS) is a potential complication of these treatments and can be particularly dangerous in these patients due to their underlying medical illness and by delaying lifesaving oncology treatment. This case report details a multipronged approach to OHSS prevention in a patient with a paraneoplastic syndrome defined by overproduction of vascular endothelial growth factor (VEGF), which is also primarily responsible for OHSS.

CASE PRESENTATION

A 29 year old nulligravid woman was diagnosed with a rare multisystem paraneoplastic syndrome (Polyradiculoneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder and skin changes, known as POEMS) and presented for fertility preservation consultation prior to autologous stem cell transplant. She successfully underwent oocyte cryopreservation without complications due to aggressive OHSS prophylaxis with both a dopamine agonist and aromatase inhibitor during and after stimulation and a gonadotropin releasing hormone agonist (GnRH-A) for final oocyte maturation, without delay in her subsequent oncology treatment.

CONCLUSIONS

This is the first report of a patient with POEMS undergoing controlled ovarian hyperstimulation (COH). Oocyte cryopreservation was successful and without complications due to a combination of prophylactic measures against OHSS (cabergoline, letrozole and GnRH-A trigger) and close collaboration between reproductive endocrinology and oncology. This case demonstrates the use of combined measures in targeting VEGF overproduction and OHSS risk during COH.

Pigment Epithelium-Derived Factor Promotes the Growth and Migration of Human Esophageal Squamous Cell Carcinoma

Pigment epithelium-derived factor (PEDF) is an oncogene found in various types of cancers. However, how PEDF affects the development of human esophageal squamous cell carcinoma (ESCC) is unknown. This study investigates the role of PEDF in ESCC cell proliferation, migration, and cell cycle both in vitro and in vivo. The PEDF expression was examined in patient tumor samples and ESCC cell lines. Short hairpin RNA technology was used to inhibit the PEDF expression in ESCC EC9706 and KYSE150 cells. In vitro cell proliferation and migration assays were performed. The effects of PEDF on tumor growth and progression were examined in vivo in murine subcutaneous xenograft tumor models. It was found that PEDF was overexpressed in esophageal cancer cells and patient tumor tissues compared to normal control samples. PEDF enhanced cell cycle progression and inhibited cell apoptosis. Knock down of PEDF inhibited esophageal cell proliferation and migration in vitro. Moreover, Inhibition of PEDF significantly reduced tumor growth and tumor size in vivo. These results indicate that PEDF induce tumorigenesis in ESCC and can be a potential therapeutic target for cancer treatment.

The role of Letrozole (LE) in controlled ovarian stimulation (COS) in patients at high risk to develop ovarian hyper stimulation syndrome (OHSS). A prospective randomized controlled pilot study

BACKGROUND

Recently, it has been shown that PCOS patients with extremely high anti-Mullerian hormone (AMH) level are more likely to experience OHSS during IVF, compared to PCOS patients with lower AMH level. While recent data questioned the effect of Letrozole (LE) on the occurrence of OHSS in non-PCOS patients, it role in PCOS patients with very high AMH level was never investigated in a prospective manners. Hence, our main objective was to evaluate the clinical outcome of PCOS patients at very high risk for OHSS undergoing two different COS protocols (with or without LE).

METHODS

A prospective randomized controlled study (RCT) of 51 patients with specifically high levels of AMH undergoing one of two COS protocols. The control group (group A) consisted of 24 PCOS women who received low-dose gonadotropins using the multiple-dose GnRH-antagonist protocol, GnRH agonist-triggered and "freeze all". The study group (group B) consisted of 24 women with PCOS who received the same protocol combined with LE. High risk criteria for OHSS were: PCOS patients with low BMI, young age, and extremely high level of serum AMH (inclusion criteria for AMH > 50 pmol/L).

RESULTS

Cumulative live birth rates per retrieval were similar in both groups. While no single case of severe OHSS was observed in, in the study group (group B), the rate of moderate and mild OHSS was 5 times lower compared to the control group (P < 0.05).

CONCLUSION

In PCOS patients with extremely high AMH levels the LE co-administration to GnRH-Ant protocols results in reduced incidence of OHSS than conventional GnRH-Ant protocols. LE co-administration may prove to be highly effective in preventing OHSS, even in the women who are at high risk to these dangerous complications.

The effect of luteal GnRH antagonist on moderate and severe early ovarian hyperstimulation syndrome during in vitro fertilization treatment: a prospective cohort study

PURPOSE

Ovarian hyperstimulation syndrome (OHSS) is a serious complication of assisted reproductive technology (ART) treatment. However, there are limited data regarding the ability of the luteal GnRH antagonist cetrorelix to reduce the incidence of moderate and severe OHSS, and the mechanism remains unclear. Thus, we designed a study to assess the effectiveness of cetrorelix to prevent early moderate and severe OHSS in high-risk patients undergoing controlled ovarian stimulation for IVF/ICSI.

METHODS

In this prospective cohort study, 105 patients with high-risk OHSS undergoing cryopreservation of all embryos were divided into two groups according to their personal choice. The cetrorelix group (n = 65) received 0.25 mg of cetrorelix by subcutaneous injection daily, from days 3 to 5 post-oocyte retrieval (POR); the control group (n = 40) received no drug. The primary outcome measures were the incidence and severity of early moderate and severe OHSS. Secondary measures included serum estradiol levels, ovarian volume, ascites volume, hematocrit values, and WBC count on days 3, 6, and 9 POR. VEGF and EGR-1 levels were assessed, and binary logistic regression analysis was applied to predict associations between clinical variables and OHSS.

RESULTS

Ninety-six patients were examined. The incidence of moderate and severe OHSS was significantly lower in the cetrorelix group than in the control group (18.03% and 37.14%, respectively; P = 0.037). Serum estradiol (P = 0.013), white blood cell count (P = 0.031), ascites volume (P = 0.036), EGR-1 (P = 0.025), and VEGF levels (P = 0.015) were significantly higher in the control group on day 6 POR than on day 3 POR, while no increase was observed between day 3 POR and day 6 POR in the cetrorelix group, indicating a faster regression of OHSS symptoms. Cetrorelix intervention was associated with the incidence and severity of OHSS (OR 0.29, 95% CI 0.11-0.78, P = 0.014).

CONCLUSION

Cetrorelix effectively reduces the incidence of early moderate and severe OHSS in high-risk women and decreases serum VEGF levels.

What is the impact of short- and long-term supplementation of either cabergoline or clarithromycin on resolving rat ovarian hyperstimulation syndrome (OHSS) model?

This study aimed to evaluate the effects of coasting, cabergoline and clarithromycin in a rat ovarian hyperstimulation syndrome (OHSS) model. The 42 female Wistar rats were divided into seven groups: control, OHSS (was given 10 IU of pregnant mare serum gonadotropin for 4 consecutive days from day 22 and 30 IU hCG on the fifth day to induce OHSS ), coasting (hCG was applied on the 27th day after gonadotropin injections and the rats were decapitated on the 28th day), Cabergoline (100 mg/kg/d) and clarithromycin (100 mg/kg/d) were given (on the 26th day) with a short-term supplementation (on the 26th day) and long-term supplementation (from the 22nd to the 26th day) groups. The rats were decapitated on the 27th day. Cabergoline and clarithromycin significantly lowered VEGF-2 levels. Clarithromycin significantly reduced IL-1b and TNF-a and significantly increased IL-10 levels. Clarithromycin may be an effective drug for the treatment of OHSS. Impact statement What is already known on this subject? Ovarian hyper-stimulation syndrome (OHSS) is a self-limited disease, in which vascular endothelial growth factor (VEGF) plays the most important role and has a large clinical spectrum related with increased capillary permeability and fluid retention. Some treatment methods that block VEGF over-expression are used in treatment of OHSS. Clarithromycin is known to suppress the production of some pro-inflammatory molecules such as VEGF, IL-8, IL-1, IL-6 and TNF-a. In our study, we compared the efficacy of coasting, short- and long-term supplementation of clarithromycin and cabergoline on correcting OHSS parameters in an experimental study. What do the results of this study add? As a result of our study, we found that OHSS parameters improved better in early prophylactic treatment regimens. We have shown that clarithromycin may be a more effective treatment agent than coasting and cabergoline. What are the implications of these findings for clinical practice and/or further research? Although our study is important in that it is the first pilot study to show that clarithromycin is effective in the treatment of OHSS, there is a need for larger clinical trials.

A Retrospective Study of Letrozole Treatment Prior to Human Chorionic Gonadotropin in Women with Polycystic Ovary Syndrome Undergoing In Vitro Fertilization at Risk of Ovarian Hyperstimulation Syndrome

Background

Women with polycystic ovary syndrome (PCOS) undergoing in vitro fertilization (IVF) are given letrozole before a trigger injection of human chorionic gonadotropin (hCG) to lower estrogen (E₂) levels, but can experience ovarian hyperstimulation syndrome (OHSS). The aim of this study was to evaluate the effect of oral letrozole, prior to administration of hCG, on the outcome of IVF and development of OHSS.

Material/Methods

Retrospective clinical review included 181 cases of women with PCOS who underwent IVF cycles with intracytoplasmic sperm injection (ICSI) and embryo transfer (ET) (IVF/ICSI-ET). The day before the use of hCG, cases were divided into a letrozole-treated group (N=78) and a non-letrozole group (N=103). An oral dose of 2.5 mg qd of letrozole was given when the peak level of E₂ was ≥4000 pg/ml during ovarian stimulation and ceased before the day of egg retrieval.

Results

The letrozole-treated group had a significant increase in the number of retrieved oocytes, viable embryos, and fresh ET rate (P>0.05); peak levels of E₂, and E₂ levels on the day of the egg retrieval, were significantly higher, and the fertilization rate was significantly lower (P<0.001). No significant differences were found in the rates of pregnancy, abortion, or ectopic pregnancy between the two groups (P>0.05). The incidence OHSS was lower in the letrozole-treated group, but this difference did not reach statistical significance (P>0.05).

Conclusions

Women with PCOS who underwent IVF, oral treatment with letrozole a day prior to treatment with hCG lowered E₂ levels, but did not significantly reduce the incidence of OHSS.

The VEGF and PEDF levels in the follicular fluid of patients co- treated with LETROZOLE and gonadotropins during the stimulation cycle

BACKGROUND

Previous studies have shown that androgens, in addition to serving as precursors for ovarian estrogen synthesis, also have a fundamental role in primate ovarian follicular development by augmentation of FSH receptor expression on granulosa cells. Recent studies have shown that aromatase inhibitor, letrozole, improves ovarian response to FSH in normal and poor responder patients, possibly by increasing intraovarian androgen levels. Studies in mice also showed an effect of letrozole to increase pigment epithelium-derived factor (PEDF) and to lower vascular epithelial growth factor (VEGF), which might be expected to reduce the risk of ovarian hyperstimulation syndrome (OHSS) with stimulation. The aim of this study was to compare the VEGF and PEDF levels in the follicular fluids of normal responders treated with letrozole and gonadotropins during the ovarian stimulation with patients treated with gonadotropins only.

METHODS

A single center, prospective clinical trial. We collected follicular fluid from 26 patients, on a GnRH antagonist protocol, dual triggered with hCG and GnRH agonist. The patients in one group were co-treated with letrozole and gonadotropins during the ovarian stimulation and the patients in the other group were treated with gonadotropins only. VEGF, PEDF, estrogen, progesterone and testosterone levels were measured by ELISA kits.

RESULTS

The age of the patients, the total dose of gonadotropins and the number of oocytes were comparable between the two groups. In the follicular fluid, the estrogen levels (2209 nmol/l vs. 3280 nmol/l, p = 0.02) were significantly decreased, and the testosterone levels (246.5 nmol/l vs. 40.7 nmol/l, p < 0.001) were significantly increased in the letrozole group compared to the gonadotropin only group. The progesterone levels (21.4 μmol/l vs. 17.5 p = NS) were comparable between the two groups. The VEGF levels (2992 pg/ml vs. 1812 pg/ml p = 0.02) were significantly increased and the PEDF levels (9.7 ng/ml vs 17.3 ng/ml p < 0.001) were significantly decreased in the letrozole group.

CONCLUSIONS

Opposite to observations in the mouse, we found that VEGF levels were increased and PEDF levels were decreased in the follicular fluid in patients treated with letrozole during the stimulation cycles. Further investigation is required to determine if patients treated with letrozole during the IVF stimulation protocol are at increased risk for developing OHSS as a result of these findings.

Sequential E2 levels not ovarian maximal diameter estimates were correlated with outcome of cetrotide therapy for management of women at high-risk of ovarian hyperstimulation syndrome: a randomized controlled study

Background

Ovarian hyperstimulation syndrome (OHSS) is an important condition with considerable morbidity and a small risk of mortality and most commonly results as an iatrogenic condition following follicular stimulation of the ovaries. We aimed to evaluate safety and efficacy of 3-day cetrotide therapy started on day of oocyte retrieval (Day-0) in women at high-risk for development of ovarian hyperstimulation syndrome (OHSS) after GnRH agonist induction protocol.

Methods

Forty-eight women fulfilling inclusion criteria underwent ultrasound scanning for maximal ovarian diameter (MOD) estimation and ascites grading. Patients underwent embryo freezing, but the study group received 3-day Cetrotide sc injection (0.25 mg/day) started on Day-0. Serum E2, pain scores and MOD were checked daily. Hematocrite value (Ht%), total leucocytic count (TLC), gastrointestinal (GI) manifestations and ascites grading were re-evaluated on Day-3, 6 and 8.

Results

Sequential serum E2 levels decreased significantly in both groups with significantly lower levels in the study group. Sequential MOD estimates showed non-significant difference between the two groups and versus Day-0 estimates. On Day-2, pain scores showed progressive significant decrease compared to Day-0 scores in both groups with significantly lower scores in the study group. On Day-3; four control patients still had vomiting and by Day-6, 6 of the control patients still had GI manifestations with significant difference versus the study group. Compared to Day-0 estimates, Ht% and TLC were significantly lower on Day-3, 6 and 8 in the study group, but only on Day-8 in the control group. Day-3 and Day-8 ascites grading in both groups was significantly lower compared to respective Day-0 grading with significant difference in favor of the study group. Six patients required hospitalization, but without mortalities. Day-3 E2 levels in the study group showed positive significant correlation with clinical and other laboratory data and ascites grading, while the correlation was non-significant with MOD.

Conclusion

The 3-day cetrotide therapy starting after oocyte retrieval with embryo transfer freezing could be an appropriate management policy for women received GnHR-agonist induction protocol and were at high-risk for OHSS. Sequential E2 serum levels could predict outcome more perfectly than sequential MOD estimates.

Trial registration

Trial registration (clinicaltrial.gov registration) NCT02823080 (retrospective) Initial Release 21–6-2016 Last Release 3–1-2017 Unique Protocol ID: Benha U Secondary IDs: kmsalama.

Kisspeptin-10 inhibits OHSS by suppressing VEGF secretion

The aim of the present study was to elucidate the effects of kisspeptin-10 (Kp-10) on ovarian hyperstimulation syndrome (OHSS) and its related mechanism in OHSS rat models, human umbilical vein endothelial cells (HUVECs) and human luteinized granulosa cells. OHSS is a systemic disorder with high vascular permeability (VP) and ovarian enlargement. KISS1R (KISS1 receptor) is the specific receptor of kisspeptin. The kisspeptin/KISS1R system inhibits the expression of vascular endothelial growth factor (VEGF), which is the main regulator of VP. In our study, decreased expression of Kiss1r was observed in both ovaries and lung tissue of OHSS rats. Injection of exogenous Kp-10 inhibited the increase of VP and VEGF while promoting the expression of Kiss1r in both the ovarian and lung tissue of OHSS rats. Using HUVECs, we revealed that a high level of 17-β estradiol (E2), a feature of OHSS, suppressed the expression of KISS1R and increased VEGF and nitric oxide (NO) through estrogen receptors (ESR2). Furthermore, KISS1R mRNA also decreased in the luteinized human granulosa cells of high-risk OHSS patients, and was consistent with the results in rat models and HUVECs. In conclusion, Kp-10 prevents the increased VP of OHSS by the activation of KISS1R and the inhibition of VEGF.

Does daily co-administration of letrozole and gonadotropins during ovarian stimulation improve IVF outcome?

BACKGROUND

For the last year we have been treating normal responders with gonadotropins and letrozole during the whole stimulation in order to improve response to FSH by increasing the intrafollicular androgen concentration, and to reduce circulating estrogen concentrations. The aim of this study was to compare the IVF outcome of normal responders treated with letrozole and gonadotropins during ovarian stimulation with patients treated with gonadotropins only.

METHODS

A single centre retrospective cohort study of 174 patients (87 in each group).

RESULTS

The age of the patients was comparable between the groups. Estradiol levels were significantly higher in the control group (6760 pmol/L vs. 2420 pmol/L respectively, p < 0.01), and the number of follicles ≥15 mm at the trigger day was significantly lower in the control group (7.9 vs. 10, p = 0.02). The number of retrieved oocytes (10 vs. 14.5, p < 0.01), MII oocytes (7.9 vs. 11.2, p < 0.01) and blastocysts (2.7 vs. 4.0, p = 0.02) was significantly higher in the study group. We found no significant differences in the cumulative pregnancy outcome between the two groups (65.2% vs 58.3% p = NS).

CONCLUSIONS

We conclude that co-treatment with letrozole improves the IVF outcome in normal responders in terms of increased number of blastocysts obtained without increasing the pregnancy rate or the risk of OHSS.

Modification of the Tumor Microenvironment in KRAS or c-MYC-Induced Ovarian Cancer-Associated Peritonitis

The most common properties of oncogenes are cell proliferation and the prevention of apoptosis in malignant cells, which, as a consequence, induce tumor formation and dissemination. However, the effects of oncogenes on the tumor microenvironment (TME) have not yet been examined in detail. The accumulation of ascites accompanied by chronic inflammation and elevated concentrations of VEGF is a hallmark of the progression of ovarian cancer. We herein demonstrated the mechanisms by which oncogenes contribute to modulating the ovarian cancer microenvironment. c-MYC and KRAS were transduced into the mouse ovarian cancer cell line ID8. ID8, ID8-c-MYC, or ID8-KRAS cells were then injected into the peritoneal cavities of C57/BL6 mice and the production of ascites was assessed. ID8-c-MYC and ID8-KRAS both markedly accelerated ovarian cancer progression in vivo, whereas no significant differences were observed in proliferative activity in vitro. ID8-KRAS in particular induced the production of ascites, which accumulated between approximately two to three weeks after the injection, more rapidly than ID8 and ID8-c-MYC (between nine and ten weeks and between six and seven weeks, respectively). VEGF concentrations in ascites significantly increased in c-MYC-induced ovarian cancer, whereas the concentrations of inflammatory cytokines in ascites were significantly high in KRAS-induced ovarian cancer and were accompanied by an increased number of neutrophils in ascites. A cytokine array revealed that KRAS markedly induced the expression of granulocyte macrophage colony-stimulating factor (GM-CSF) in ID8 cells. These results suggest that oncogenes promote cancer progression by modulating the TME in favor of cancer progression.