Case report: Response to everolimus in a patient with platinum resistant, high grade serous ovarian carcinoma with biallelic TSC2 inactivation.

Background: Patients with platinum-resistant recurrent high grade serous ovarian carcinoma have poor outcomes and limited treatment options. Case presentation: We present a case of a 48-year-old woman with platinum-resistant high grade serous ovarian carcinoma harboring the pathogenic TSC2 R611Q variant with concomitant single copy loss of TSC2 (suggesting biallelic TSC2 inactivation) identified in targeted tumor sequencing. The patient was treated with the mTOR inhibitor everolimus, with an excellent response by imaging and a marked decrease in CA125; she remained on everolimus for 19 months until she developed progressive disease. Conclusions: While mTOR inhibition is frequently used in tumors associated with tuberous sclerosis complex (TSC), such as lymphangioleiomyomatosis and malignant perivascular epithelioid cell tumors, this is the first case of a patient with ovarian cancer harboring TSC1/2 mutations who responded to mTOR inhibition. This case highlights the utility of targeted DNA sequencing in the management of ovarian carcinoma and demonstrates the value of tumor-agnostic targeted therapies.

Preparation of UiO-66 loaded Letrozole nano-drug delivery system: enhanced anticancer and apoptosis activity.

The use of drug delivery systems in targeting and achieving the targeting of drugs in treating diseases, especially cancer, has attracted the attention of researchers. Letrozole is one of the drugs for the treatment of breast cancer. In this study, the organic-metallic pharmaceutical porous nanostructure based on zirconium UiO-66 loaded letrozole was synthesized. Its cytotoxicity and effect on apoptosis and migration against breast cancer cell line were investigated. In this experimental study, the UiO-66 nanoparticle-loaded letrozole was synthesized using zirconium chloride (ZrCl4), dimethylformamide (DMF), and HCl. Its characteristics were determined by scanning electron microscopy, and its average size was determined by the DLS method. Also, the rate of letrozole drug release from the nanoparticle was investigated in 24, 48, and 72 h. In addition, its cytotoxicity effects were investigated using the MTT colorimetric method at concentrations of 3.125-100 µg/ml against the breast cancer cell line (MCF-7) in the periods of 48 and 72 h. Also, the expression level of apoptotic genes Bax and Bcl2 was investigated by the Real-Time PCR method. Also, the amount of cell migration was done by the migration assay method. The results showed that UiO-66 bound to letrozole had a spherical morphology and an average size of 9.2 ± 160.1. Also, the letrozole drug was loaded by 62.21 ± 1.80% in UiO-66 nanoparticles and had a slower release pattern than free letrozole in the drug release test, so within 72 h, 99.99% of free letrozole was released in If in UiO-66 containing letrozole, 57.55% of the drug has been released. Also, the cytotoxicity results showed that UiO-66 bound to letrozole has more significant cytotoxic effects than free letrozole (p < 0.05). Also, the results of Bax and Bcl2 gene expression showed that the treatment of MCF-7 cells with UiO-66 nanoparticles attached to letrozole increased the expression of Bax and Bcl2 genes compared to the reference gene Beta-actin in MCF-7 cell line, respectively. (p < 0.05) increased by 3.71 ± 0.42 and (p < 0.01) decreased by 0.636 ± 0.034 (p < 0.05). Cell migration results showed that the concentration of 50 µg/ml of UiO-66 bound to letrozole decreased the migration of MCF-7 cells. Generally, the results of this study showed that UiO-66 loaded letrozole can be used as a suitable drug carrier for cellular purposes, as it has increased the effects of cytotoxicity and the rate of apoptosis in breast cancer cell line (MCF-7), so it can be used with more studies used nanocarriers as a drug delivery system.

Quantification of the aromatase inhibitor letrozole and its carbinol metabolite in mouse plasma by UHPLC-MS/MS.

A liquid chromatography - electrospray ionization-mass spectrometry (LC-ESI-MS) method was developed for the quantification of letrozole, a third-generation aromatase inhibitor, and its main carbinol metabolite (CM) in support of murine pharmacokinetic studies. Using polarity switching, simultaneous ESI-MS measurement of letrozole and CM was achieved in positive and negative mode, respectively. The assay procedure involved a one-step protein precipitation and extraction of all analytes from mouse plasma requiring only 5 µL of sample. Separation was optimized on an Accucore aQ column with gradient elution at a flow rate of 0.4 mL/min in 5 min. Two calibration curves per day over four consecutive measurement days showed satisfactory linear responses (r2 > 0.99) over concentration ranges of 5-1000 ng/mL and 20-2000 ng/mL for letrozole and CM, respectively. No matrix effect was found, and the mean extraction recoveries were 103-108 % for letrozole and 99.8-107 % for CM. Precision and accuracy within a single run and over four consecutive measurement days were verified to be within acceptable limits. Application of the developed method to preclinical pharmacokinetic studies in mice receiving oral letrozole at a dose 1 or 10 mg/kg revealed that the systemic exposure to letrozole was dose-, formulation-, and strain-dependent. These findings may inform the future design of preclinical studies aimed at refining the pharmacological profile of this clinically important drug.

Sodium oligomannate's amelioration of reproductive and metabolic phenotypes in a letrozole-induced PCOS-like mouse model depends on the gut microbiome.

It has been well-established that there is a connection between polycystic ovary syndrome (PCOS) pathology and gut microbiome dysbiosis. A marine-derived oligosaccharide, GV-971, has been reported to alter gut microbiota and alleviate Aß amyloidosis. In this study, the effects of GV-971 on PCOS-like mice were explored. Mice were randomly assigned into four groups: control, letrozole, letrozole + GV-971, control + GV-971. Glucose metabolism in PCOS-like mice was ameliorated by GV-971, while the reproductive endocrine disorder of PCOS-like mice was partially reversed. The messenger ribonucleic acid levels of steroidogenic enzymes in ovaries of PCOS-like mice were improved. GV-971 restored the fertility of PCOS-like mice and significantly increase the number of litters. Furthermore, GV-971 treatment effectively mitigated abnormal bile acid metabolism. Notably, after GV-971 intervention, gut microbiota alpha-diversity was considerably raised and the relative abundance of Firmicutes was reduced. In conclusion, the hyperinsulinemia and hyperandrogenemia of PCOS-like mice were alleviated by GV-971 intervention, which was associated with mitigating bile acid metabolism and modulating gut microbiota.

Tumor lysis syndrome following letrozole for locally advanced breast cancer: a case report.

BACKGROUND: Letrozole, an aromatase inhibitor, is used to treat breast cancer in postmenopausal women. Tumor lysis syndrome (TLS) is a complication that can trigger multiple organ failure caused by the release of intracellular nucleic acids, phosphate, and potassium into the blood due to rapid tumor cell disintegration induced by drug therapy. TLS is uncommon in solid tumors and occurs primarily in patients receiving chemotherapy. Herein, we report a rare occurrence of TLS that developed in a patient with locally advanced breast cancer following treatment with letrozole. CASE PRESENTATION: An 80-year-old woman with increased bleeding from a fist-sized left-sided breast mass presented to our hospital. Histological examination led to a diagnosis of invasive ductal carcinoma of the luminal type. The patient refused chemotherapy and was administered hormonal therapy with letrozole. Seven days after letrozole initiation, she complained of anorexia and diarrhea. Blood test results revealed elevated blood urea nitrogen (BUN) and creatinine (Cr) levels, and she was admitted to our hospital for intravenous infusions. On the second day after admission, marked elevations of LDH, BUN, Cr, potassium, calcium, and uric acid levels were observed. Furthermore, metabolic acidosis and prolonged coagulation capacity were observed. We suspected TLS and discontinued letrozole, and the patient was treated with hydration, febuxostat, and maintenance hemodialysis. On the third day after admission, her respiratory status worsened because of acute respiratory distress syndrome associated with hypercytokinemia, and she was intubated. On the fourth day after admission, her general condition did not improve, and she died. CONCLUSIONS: Although TLS typically occurs after chemotherapy initiation, the findings from the present case confirm that this syndrome can also occur after hormonal therapy initiation and should be treated with caution.

Superior suppression of serum estrogens during neoadjuvant breast cancer treatment with letrozole compared to exemestane.

PURPOSE: The aromatase inhibitor letrozole and the aromatase inactivator exemestane are two of the most pivotal cancer drugs used for endocrine treatment of ER-positive breast cancer in all phases of the disease. Although both drugs inhibit CYP19 (aromatase) and have been used for decades, a direct head-to-head, intra-patient-cross-over comparison of their ability to decrease estrogen synthesis in vivo is still lacking. METHODS: Postmenopausal breast cancer patients suitable for neoadjuvant endocrine therapy were randomized to receive either letrozole (2.5 mg o.d.) or exemestane (25 mg o.d.) for an initial treatment period, followed by a second treatment period on the alternative drug (intra-patient cross-over study design). Serum levels of estrone (E1), estradiol (E2), letrozole, exemestane, and 17-hydroxyexemestane were quantified simultaneously using a novel, ultrasensitive LC-MS/MS method established in our laboratory. RESULTS: Complete sets of serum samples (baseline and during treatment with letrozole or exemestane) were available from 79 patients, including 40 patients starting with letrozole (cohort 1) and 39 with exemestane (cohort 2). Mean serum estrone and estradiol levels in cohort 1 were 174 pmol/L and 46.4 pmol/L at baseline, respectively. Treatment with letrozole suppressed serum E1 and E2 to a mean value of 0.2 pmol/L and 0.4 pmol/L (P < 0.001). After the cross-over to exemestane, mean serum levels of E1 and E2 increased to 1.4 pmol/L and 0.7 pmol/L, respectively. In cohort 2, baseline mean serum levels of E1 and E2 were 159 and 32.5 pmol/L, respectively. Treatment with exemestane decreased these values to 1.8 pmol/L for E1 and 0.6 pmol/L for E2 (P < 0.001). Following cross-over to letrozole, mean serum levels of E1 and E2 were significantly further reduced to 0.1 pmol/L and 0.4 pmol/L, respectively. Serum drug levels were monitored in all patients throughout the entire treatment and confirmed adherence to the protocol and drug concentrations within the therapeutic range for all patients. Additionally, Ki-67 values decreased significantly during treatment with both aromatase inhibitors, showing a trend toward a stronger suppression in obese women. CONCLUSION: To the best of our knowledge, we present here for the first time a comprehensive and direct head-to-head, intra-patient-cross-over comparison of the aromatase inhibitor letrozole and the aromatase inactivator exemestane concerning their ability to suppress serum estrogen levels in vivo. All in all, our results clearly demonstrate that letrozole therapy results in a more profound suppression of serum E1 and E2 levels compared to exemestane.

Mitigation of letrozole induced polycystic ovarian syndrome associated inflammatory response and endocrinal dysfunction by Vitex negundo seeds.

BACKGROUND: Polycystic ovary syndrome (PCOS) is a complex endocrine disorder in women that necessitates effective and safe treatment alternatives. This study aimed to evaluate the therapeutic efficacy of Vitex negundo seed in a letrozole-induced PCOS rat model. RESULTS: Findings of the present study demonstrated that administration of hydro-ethanolic extract of Vitex negundo (VNE) effectively restored endocrino-metabolic imbalances associated with PCOS, along with correction of antioxidant enzymes level, proinflammatory cytokines, and apoptotic bio-markers. LC-MS analysis confirmed the presence of cinnamic acid, plumbagin and nigundin B as the prominent phytochemicals in VNE. The observed beneficial effects could be attributed to the active compounds in Vitex negundo extract, which exhibited hypoglycemic, hypolipidemic, and catabolic effects on body weight. Additionally, the extract contributed to hormonal balance regulation by modulating the steroidogenic enzymes, specifically by tuning gonadotropins level and correcting the LH:FSH ratio, through the modulation of ERα signalling and downregulation of NR3C4 expression. The antioxidant properties of phytochemicals in Vitex negundo seed were apparent through the correction of SOD and catalase activity. While it's anti-inflammatory and antiapoptotic action were associated with the regulation of mRNA expression of TNF-α, IL-6, BAX, Bcl2. Molecular docking study further indicated the molecular interaction of above mentioned active phytocompounds of VNE with ERα, NR3C4 and with TNFα that plays a critical mechanistic gateway to the regulation of hormone signalling as well as synchronizing the inflammation cascade. Furthermore, the histomorphological improvement of the ovaries supported the ameliorative action of Vitex negundo extract in the letrozole-induced PCOS model. CONCLUSIONS: This study indicates the potential of Vitex negundo seed as a multifaceted therapeutic option for PCOS. VNE offers a holistic strategy for PCOS with antiandrogenic, anti-inflammatory, and antioxidant properties, driven by its major compounds like cinnamic acid, plumbagine, and nigundin B.

Acantholytic Dyskeratosis Consistent With Grover's Disease After Letrozole Therapy.

We present a rare case of Grover's disease (GD) associated with letrozole therapy in a 66-year-old female with stage IV breast cancer. GD is a dermatological condition characterized by papulovesicular lesions typically found on the chest and trunk. While GD is linked to chemotherapeutic agents, its association with letrozole is not well documented. The patient presented with a pruritic rash on her neck, right arm, and trunk, initially misdiagnosed as contact dermatitis. Despite treatment with triamcinolone acetonide, the rash persisted. A subsequent punch biopsy confirmed acantholytic dyskeratosis consistent with GD. Discontinuation of letrozole and treatment with augmented betamethasone dipropionate resulted in significant improvement within four weeks. This case underscores the importance of considering drug-induced dermatological conditions in patients undergoing chemotherapy. While hypersensitivity drug eruptions typically present as morbilliform-patterned cutaneous eruptions, GD should be considered, especially in older patients with multiple medications. The incidence of GD following letrozole therapy is not well studied, making this case a valuable addition to the limited literature. In summary, recognizing and managing drug-induced skin conditions in cancer patients are crucial. This report contributes to our understanding of the potential association between letrozole and GD, emphasizing the need for further research in this area.

Effects of Letrozole Treatment and Vitamin C Supplementation on Morphology, Endoplasmic Reticulum Stress, Programmed Cell Death, and Oxidative Stress in the Small Intestine of Adult Male Rats.

Estrogens are hormones that play an important role in the digestive tract, including in men. Letrozole is an inhibitor of cytochrome P450 aromatase, an enzyme converting androgens to estrogens. The use of letrozole may cause oxidative stress and endoplasmic reticulum stress in the cells. Factors modulating cellular stress may include vitamin C. The purpose of this study was to examine whether letrozole and/or vitamin C supplementation can affect the morphology of the small intestine, the parameters of endoplasmic reticulum stress, programmed cell death markers, and oxidative damage. Three-month-old male rats were divided into four groups and treated with the following: (I) CTRL-water; (II) CTRL+C-L-ascorbic acid; (III) LET-letrozole; and (IV) LET+C-letrozole + L-ascorbic acid. The morphometrical measurements included epithelial thickness, crypt and lumen area, crypt perimeter, nuclei number in the crypt, and the cell size of crypts. The expression levels of PERK, caspase-3, and catalase were determined. Significant differences in the morphometrical measurements and immunoexpression were observed. This may indicate that chronic treatment with letrozole can affect morphology and induce ER stress, oxidative stress, and programmed cell death in the epithelial cells of the small intestine of adult male rats. Vitamin C supplementation exerts an effect on some parameters of the molecular processes.

Relapsing eosinophilic pneumonia in a patient with recurrent breast cancer receiving abemaciclib plus endocrine therapy.

This report presents the case of a 42-year-old Japanese woman with recurrent hormone receptor-positive breast cancer who developed eosinophilic pneumonia (EP) during treatment with abemaciclib combined with endocrine therapy. Seven years after a radical surgery and definite diagnosis of Stage I breast cancer, her cancer recurred with metastases to multiple organs. Initially treated with abemaciclib plus letrozole and goserelin for 3 months, she developed EP, which improved after the discontinuation of anti-cancer treatment and the administration of prednisolone. However, EP occurred again upon the reintroduction of endocrine therapy (i.e., letrozole and goserelin). It improved gradually with the suspension of endocrine therapy and the re-administration of prednisolone. This case underscores the need for further research into the prevention and management of EP in patients receiving abemaciclib with endocrine therapy for advanced breast cancer.

Evaluation of the Impact of Letrozole in Combination with the GnRH Antagonist Ovarian Stimulation Protocol in Patients Expected to Have a Poor Ovarian Response (POSEIDON Groups 3 and 4).

Background and Objectives: The objective of this study was to evaluate the impact of adjuvant letrozole administration during ovarian stimulation using the gonadotropin-releasing hormone (GnRH) antagonist protocol on treatment outcomes in women categorized into POSEIDON groups 3 and 4. Materials and Methods: This retrospective cohort study analyzed data from patients classified into POSEIDON groups 3 and 4 who underwent fresh embryo transfer subsequent to intracytoplasmic sperm injection following a GnRH antagonist stimulation protocol between January 2017 and December 2021. Patients were divided into two groups: the GnRH-LZ group, who received letrozole at a dosage of 5 mg/day for five consecutive days, and the GnRH-ant group, who did not receive adjuvant letrozole. The primary outcome measure of the study was a comparative analysis of live birth rates between the two groups. Results: A total of 449 patients were deemed suitable for final analysis and were allocated into two groups: 281 patients in the GnRH-ant group and 168 patients in the GnRH-LZ group. Live birth rates were found to be comparable in both groups (11% vs. 9%, p = 0.497). Letrozole administration significantly reduced the total amount of gonadotropins required (2606.2 ± 1284.5 vs. 3097.8 ± 1073.3, p < 0.001), the duration of ovarian stimulation (11.2 ± 3.9 vs. 10.2 ± 3, p = 0.005), and the serum peak estradiol concentration (901.4 ± 599.6 vs. 463.8 ± 312.3, p < 0.001). Conclusions: Adjuvant letrozole administration did not demonstrate a significant impact on live birth rates among women categorized into POSEIDON groups 3 and 4. However, this approach may offer potential cost reductions by diminishing the necessity for exogenous gonadotropins and shortening the duration of ovarian stimulation.

Aromatase Inhibitors and Plasma Lipid Changes in Postmenopausal Women with Breast Cancer: A Systematic Review and Meta-Analysis.

Background: Women are typically diagnosed with estrogen receptor-positive breast cancer around the postmenopausal period when declining estrogen levels initiate changes in lipid profiles. Aromatase inhibitors (AI) are used to prevent the progression of cancer; however, a further reduction in estrogen levels may have detrimental effects on lipid levels, which was our working hypothesis. Methods: Our meta-analysis was conducted on the lipid profiles of postmenopausal breast cancer patients at baseline and at different treatment time points. Results: We identified 15 studies, including 1708 patients. Studies using anastrozole (ANA), exemestane (EXE), letrozole (LET), and tamoxifen (TMX) were involved. Subgroup analyses revealed that 3- and 12-month administrations of LET and EXE lead to negative changes in lipid profiles that tend to alter the lipid profile undesirably, unlike ANA and TMX. Conclusions: Our results suggest that, despite statistically significant results, EXE and LET may not be sufficient to cause severe dyslipidemia in patients without cardiovascular comorbidities according to the AHA/ACC Guideline on the Management of Blood Cholesterol. However, the results may raise the question of monitoring the effects of AIs in patients, especially those with pre-existing cardiovascular risk factors such as dyslipidemia.

Neonatal Aromatase Inhibition Blocked Defeminization of AVPV Kiss1 Neurons and LH Surge-Generating System in Male Rats.

The neuroendocrine system that controls the preovulatory surge of gonadotropin-releasing hormone (GnRH)/luteinizing hormone (LH), which triggers ovulation in female mammals, is sexually differentiated in rodents. A transient increase in circulating testosterone levels in male rats within a few hours of birth is primarily responsible for the defeminization of anteroventral periventricular nucleus (AVPV) kisspeptin neurons, which are critical regulators of the GnRH/LH surge. The present study aimed to determine whether neonatal estradiol-17ß (E2) converted from testosterone by aromatase primarily causes the defeminization of AVPV kisspeptin neurons and the surge of GnRH/LH in male rodents. The results of the present study showed that the neonatal administration of letrozole (LET), a nonsteroidal aromatase inhibitor, within 2 hours of birth rescued AVPV Kiss1 expression and the LH surge in adult male rats, while the neonatal administration of testosterone propionate (TP) irreversibly attenuated AVPV Kiss1 expression and the LH surge in adult female rats. Furthermore, the neonatal LET-treated Kiss1-Cre-activated tdTomato reporter males exhibited a comparable number of AVPV Kiss1-Cre-activated tdTomato-expressing cells to that of vehicle-treated female rats, while neonatal TP-treated females showed fewer AVPV Kiss1-Cre-activated tdTomato-expressing cells than vehicle-treated females. Moreover, neonatal TP administration significantly decreased the number of arcuate Kiss1-expressing and Kiss1-Cre-activated tdTomato-positive cells and suppressed LH pulses in adult gonadectomized female rats; however, neonatal LET administration failed to affect them. These results suggest that E2 converted from neonatal testosterone is primarily responsible for the defeminization of AVPV kisspeptin neurons and the subsequent GnRH/LH surge generation in male rats.

Sulforaphane's role in Redefining autophagic Responses in depression associated with polycystic ovarian syndrome: Unveiling the SIRT1/AMPK/LKB1 pathway connection.

Polycystic ovarian syndrome (PCOS) has been associated with depression and suicidal ideations in females. Studies have highlighted the role of autophagic deficiency in depression pathogenesis. Sulforaphane (SFN) is a natural product that improved autophagic deficiency and showed antidepressant activity in depressed patients. Herein, the study aimed to evaluate the impact of using SFN on depression-associated with PCOS via hippocampal energy sensors and cellular bioenergetics. PCOS was induced by administering letrozole (1 mg/kg, p. o.) for 21 days, followed by SFN treatment (0.5 mg/kg, i. p.) for one week. Two days before euthanasia, PCOS rats showed anhedonic behavior in the sucrose preference test and increased immobility time in the forced swimming test. Depressed rats showed a reduction in nuclear SIRT1 and an elevated cytoplasmic one. This was associated with a reduction in phosphorylation of energy sensors, liver kinase B1 (LKB1), and adenosine monophosphate kinase (AMPK), along with an imbalance of autophagic markers such as Beclin-1, microtubule-associated protein I/II light chain 3, autophagy enzyme 7 and selective autophagy receptor P62. Additionally, Nrf2 and KEAP1 levels were decreased. These abnormalities were alleviated by SFN treatment, as evidenced by the nuclear translocation of SIRT1 and the repression of downstream proteins, including FOXO1, NF-κB, and TNF-α production. These changes were reflected in improved behavioral performance in the sucrose preference test (SPT) and forced swimming test (FST). The antidepressant effects of SFN were counteracted by an autophagic inhibitor, 3-methyladenine. Eventually, SFN, as a nutraceutical, has a promising antidepressant effect via restoring autophagic-related depression in the PCOS rat model.

Letrozole induced a polycystic ovary syndrome model in zebrafish by interfering with the hypothalamic-pituitary-gonadal axis.

Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disease in women of childbearing age, with an incidence of 5-10%. This study compared the traits of zebrafish with three diagnostic criteria for human PCOS, and the diagnostic criteria for zebrafish PCOS were proposed: decreased fecundity, elevated testosterone (T) or 11-ketotestosterone (11-KT) levels and increased cortical-alveolar oocyte (CO) ratio, enhancing the zebrafish PCOS model's accuracy. According to the mammalian PCOS classification, the type of zebrafsh PCOS is divided into four phenotypes (A, B, C and D), but the four phenotypes of zebrafish PCOS are not fully covered in the existing studies (A and D). In this study, we successfully induced phenotype B zebrafish PCOS model using the aromatase inhibitor, letrozole (LET). That is, wild-type female zebrafish were exposed to 1000 µg/L LET for 30 days. Reproductive tests showed decreased fecundity in female zebrafish exposed to LET (Control: 132.63, 146.00, 173.00; LET: 29.20, 90.00, 82.71). Hormone analysis showed that female zebrafish exposed to LET had significantly lower 17ß-estradiol/testosterone (E2/T) ratios, indicating elevated T levels. Meanwhile, levels of 11-KT in the ovaries exposed to LET were significantly up-regulated (Control: 0.0076 pg/µg; LET: 0.0138 pg/µg). Pathological sections of the ovary showed fewer CO in the LET-exposed group (Control: 16.27%; LET: 8.38%). In summary, the zebrafish PCOS model summarized and studied in this study provide a reliable and economical tool for the screening of therapeutic drugs, as well as for the etiology research and treatment strategies of PCOS.

Effect of follicle size on pregnancy outcomes in patients undergoing first letrozole-intrauterine insemination.

BACKGROUND: Letrozole has been proven to be an effective method for inducing ovulation. However, little attention has been paid to whether the lead follicle size will affect the success rate of intrauterine insemination (IUI) with ovulation induction with alone letrozole. Therefore, we hope to investigate the effect of dominant follicle size on pregnancy outcomes on human chorionic gonadotropin (hCG) day of the first letrozole-IUI. METHODS: A retrospective cohort study design was employed. We included patients with anovulation or unexplained infertility undergoing first IUI treatment with letrozole for ovarian stimulation. According to the dominant follicle size measured on the day of hCG trigger, patients were divided into six groups (≤ 18 mm, 18.1-19.0 mm, 19.1-20.0 mm, 20.1-21.0 mm, 21.1-22.0 mm, > 22 mm). Logistic models were used for estimating the odds ratios (ORs) with their 95% confidence interval (CIs) for achieving a clinical pregnancy or a live birth. A restricted cubic spline was drawn to explore the nonlinear relationship between follicle size and IUI outcomes. RESULTS: A total of 763 patients underwent first letrozole-IUI cycles in our study. Fisher exact test showed significant differences among the six follicle-size groups in the rates of pregnancy, clinical pregnancy and live birth (P < 0.05 in each group). After adjusting the potential confounding factors, compared with the follicles ≤ 18 mm in diameter group, 19.1-20.0 mm, 20.1-21.0 mm groups were 2.3 or 2.56 times more likely to get live birth [adjusted OR = 2.34, 95%CI (1.25-4.39); adjusted OR = 2.56, 95% CI (1.30-5.06)]. A restricted cubic spline showed an inverted U-shaped relationship between the size of dominant follicles and pregnancy rate, clinical pregnancy rate, and live birth rate, and the optimal follicle size range on the day of hCG trigger was 19.1-21.0 mm. When the E2 level on the day of hCG trigger was low than 200 pg/mL, the clinical pregnancy rates of 19.1-20.0 mm, 20.1-21.0 mm groups were still the highest. CONCLUSIONS: The optimal dominant follicle size was between 19.1 and 21.0 mm in hCG-triggered letrozole-IUI cycles. Either too large or too small follicles may lead to a decrease in pregnancy rate. Using follicle size as a predicator of pregnancy outcomes is more meaningful when estrogen on the day of hCG trigger is less than 200 pg/ml.

Novel Metal-Organic Framework Nanoparticle for Letrozole Delivery: A New Advancement in Breast Cancer Treatment.

Water-stable metal-organic frameworks based on UIO-66@NH2 were synthesized to transport Letrozole into breast cancer cells. The UIO-66@NH2 nanoparticles had a spherical shape and triangular base pyramid morphology, with a size range of 100-200 nm. Fourier transform infrared spectroscopy confirmed the efficient adsorption of Letrozole on UIO-66@NH2. The drug release profile showed a gradual, pH-dependent release of Letrozole from the nanoparticles, with a significant increase in acidic environments, indicating the adaptable release potential of UIO-66@NH2@Let in the breast cancer microenvironment. The size and entrapment efficiency were more stable at 4 °C than at 25 °C. To evaluate the cytotoxic effects of UIO-66@NH2@Let, MTT assay, gene expression analysis, flow cytometry, reactive oxygen species generation, migration assay, and DAPI staining were performed. Moreover, according to IC50 results, the incorporation of Letrozole into UIO-66@NH2 significantly improved its anticancer activity. The results also showed that the developed formulations induced apoptosis through both intrinsic and extrinsic pathways and inhibited cancer progression. The efficacy of the formulations in inducing apoptosis was validated by DAPI staining microscopy and flow cytometry analysis. Therefore, the Letrozole-loaded UIO-66@NH2 MOFs developed in this study can be considered as a unique and sophisticated anticancer delivery nanosystem with promising in vitro anticancer properties.

A pilot trial of neoadjuvant pyrotinib plus trastuzumab, dalpiciclib, and letrozole for triple-positive breast cancer.

Triple-positive breast cancer (TPBC) poorly responds to current standard neoadjuvant therapy (trastuzumab plus pertuzumab and chemotherapy). Our previous MUKDEN 01 study showed a promising total pathological complete response (tpCR) rate of 30.4% with neoadjuvant pyrotinib (pan-human epidermal growth factor receptor tyrosine kinase inhibitor) plus dalpiciclib (cyclin-dependent kinase 4/6 inhibitor) and letrozole, but the efficacy remains suboptimal. This pilot study (NCT05228951) explored adding trastuzumab to this triplet neoadjuvant regimen in patients with stage II-III TPBC. The primary endpoint was tpCR (ypT0/is, ypN0) rate. Between February 2022 and June 2022, 12 patients were enrolled, and seven (58%; 95% confidence interval [CI], 27.7%-84.8%) patients achieved tpCR. The rate of residual cancer burden (RCB) 0-I was 75% (95% CI, 46.8%-91.1%). The objective response rate (ORR) was 92% (95% CI, 64.6%-98.5%). Mean Ki-67 level was significantly reduced from 45.0% (95% CI, 19.5%-70.5%) at baseline to 17.2% (95% CI, 0.7%-33.7%) after neoadjuvant therapy (p = 0.03). The most common grade 3 adverse events were diarrhea (four [33%]) and decreased neutrophil count (three [25%]). No grade 4 adverse events or treatment-related deaths occurred. This four-drug neoadjuvant regimen shows promising pathological response with an acceptable safety profile in patients with TPBC. A randomized controlled trial (NCT05638594) of this regimen is being conducted.

Gonadotropin upregulates intraovarian calpains-1 and -2 during ovarian follicular recruitment in the SD rat model.

Calpain role has been shown in the cumulus cell-oocyte complexes and, corpus luteum. We investigated the association of calpains-1 and -2 in ovarian folliculogenesis using the Sprague-Dawley (SD) rat model and steroidogenesis in the human granulosa cells (hGCs). We induced PCOS in 42-day-old SD rats by letrozole oral gavage for 21 days. Premature ovarian failure (POF) was induced in 21-day-old SD rats by 4-vinylcyclohexene diepoxide (VCD). Ovulation and ovarian hyperstimulatory (OHS) syndrome were induced by pregnant mare gonadotropin (PMSG) + human chorionic gonadotropin (hCG) treatments in 21 days SD rats, respectively. Steroidogenesis is stimulated in human granulosa cells (hGCs) by forskolin and the response of 17-beta-estradiol (E2) on calpains expression was checked in hGCs. The protein expression by immunoblotting and activity by biochemical assay of calpains-1 and -2 showed an oscillating pattern in the ovarian cycle. PMSG-induced follicular recruitment showed upregulation of calpains-1 and -2, but with no change during ovarian function cessation (POF). Upregulated calpain-2 expression and calpain activity was found in the hCG +PMSG-induced ovulation. Letrozole-induced PCOS showed downregulation of calpain-1, but upregulation of calpain-2. PMSG+hCG-induced OHS led to the upregulation of calpain-1. Letrozole and metformin separately increased the expression level of calpains-1 and -2 in the hGCs during luteinization. In conclusion, the expression levels of calpains -1 and -2 are increased with ovarian follicular recruitment by PMSG and calpain-1 is decreased in the PCOS condition, and letrozole and metformin upregulate the expression of calpains-1 and -2 during luteinization in the hGCs possibly via E2 action.

Letrozole cotreatment progestin-primed ovarian stimulation in women undergoing controlled ovarian stimulation for in vitro fertilization.

AIM: To investigate the impact of letrozole cotreatment progestin-primed ovarian stimulation (PPOS) (Le PPOS) in controlled ovarian stimulation (COS) and the pregnancy outcomes in frozen-thawed embryo transfer cycles. METHODS: This retrospective cohort study included women who underwent in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI). A total of 2575 cycles were included (1675 in the Le PPOS group and 900 in the PPOS group). The primary outcome was the clinical pregnancy rates. The secondary outcome was the live birth rates. RESULTS: In this study, propensity score matching (PSM) was performed to create a perfect match of 379 patients in each group. After matching, the numbers of oocytes retrieved, mature oocytes, fertilization, and clinical pregnancy rates were more favorable in the Le PPOS group than in the PPOS group (all p < 0.05). The multivariable analysis showed that the clinical pregnancy rate was higher in the Le PPOS than in the PPOS group (odds ratio = 1.46, 95% confidence interval: 1.05-2.04, p = 0.024) after adjusting for potentially confounding factors (age, anti-Müllerian hormone levels, antral follicular count, the type of embryo transferred, number of transferred embryos, body mass index, and follicular stimulating hormone and estradiol levels on starting day). CONCLUSIONS: This retrospective study with a limited sample size suggests that the Le PPOS protocol might be an alternative to the PPOS protocol in women undergoing COS and could lead to better pregnancy outcomes. The results should be confirmed using a formal randomized controlled trial.