The role of Letrozole in IVF treatment: new remedy or old mirage?

Aromatase inhibitors, particularly letrozole, are now established as first-line ovulation induction agents, offering an effective ovarian stimulation strategy to enhance outcomes of intrauterine insemination. In recent years, they have also emerged as potentially valuable adjuvants to gonadotropin ovarian stimulation for IVF, particularly in fertility preservation in women with estrogen-responsive cancers. Their primary mechanism of action is to reduce circulating estrogen levels by inhibiting androgen aromatization. Recent studies have provided evidence that this property may confer therapeutic advantages in other patients undergoing IVF. In this article, evidence supporting the role of adjuvant letrozole in poor responders, as a moderator of OHSS symptoms, and an agent for improving the luteal phase after ovarian stimulation is reviewed. The use of letrozole for endometrial preparation in the frozen-thawed embryo transfer cycle is also considered.

Effects of letrozole on rat placental development.

We examined the morphological effects of letrozole on placental development in pregnant rats. Letrozole was orally administered at a repeat dose to pregnant rats at 0 mg/kg (control group) and 0.04 mg/kg (letrozole group) from gestation day (GD) 6 to GD 20. In the letrozole group, fetal mortality and placental weight increased from GD 15 onwards and GD 13 onwards, respectively. Fetal weights increased on GDs 15 and 17 but decreased on GD 21. Histopathologically, letrozole treatment induced multiple cysts lined with undifferentiated syncytiotrophoblasts in the trophoblastic septa on GD 13. These cysts then develop into dilated maternal sinusoids with congestive hyperemia, resulting in an enlarged placenta. In the metrial gland, there was a dilated lumen of the spiral artery and interstitial edema throughout the experimental period, resulting in thickened metrial gland. These changes are considered to be due to maternal blood circulation stagnation in the metrial gland, which is associated with dilated maternal sinusoids in the labyrinth zone. Thus, although letrozole induces an enlarged placenta due to congestive hyperemia of the labyrinth zone and transient increases in fetal weight, these placentas are thought to decline in function as the pregnancy progresses, leading to intrauterine growth restriction at the end of pregnancy.

Novel Targeted Agents in Advanced and Recurrent Low-Grade Serous Ovarian Cancer: A Silver Lining in the Therapy of a Chemoresistant Disease?

Low-grade serous ovarian carcinoma (LGSOC) is a rare subtype of epithelial ovarian cancer, characterized by a unique molecular background and specific clinical behavior. A growing body of molecular data underscores LGSOC as a distinct disease entity; however, clinical evidence on the optimal treatment regimens for LGSOC remains limited due to the low incidence of the disease. Consequently, treatment recommendations for LGSOC are still often derived from findings on the more common high-grade serous ovarian carcinoma (HGSOC) and typically focus on radical cytoreductive surgery and platinum-based chemotherapy. Since LGSOCs typically exhibit only limited responsiveness to platinum-based chemotherapy, the clinical management of advanced and recurrent LGSOCs remains a significant therapeutic challenge and often results in limited treatment options and suboptimal outcomes. Recent advances in molecular profiling and the identification of new, promising targets, such as the mitogen-activated protein kinase (MAPK) pathway, offer hope for improving both the prognosis and health-related quality of life in affected patients. Given the high unmet clinical need to establish new therapeutic standards beyond cytotoxic chemotherapy, this review aims to summarize the most promising molecular targets and emerging targeted agents.

Impact of letrozole co-treatment in an antagonist protocol for IVF/ICSI: a retrospective study.

OBJECTIVE: The present study aimed to investigate the impact of combined use of letrozole in an antagonist protocol during IVF on live birth outcomes and to assess the safety of letrozole in terms of maternal and neonatal complications. METHODS: This retrospective cohort study included women undergoing IVF/ICSI and fresh embryo transfer (ET) treatment with and without letrozole co-treatment from 2007 to 2021 at Shanghai Ninth People's Hospital (Shanghai, China). The primary outcome was the live birth rate, while the incidences of maternal and neonatal complications were secondary outcomes. Logistic regression models were used to estimate adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for the analyzed outcomes. Sensitivity analysis was performed using a propensity score-based patient-matching (PSM) model, an inverse probability weighting (IPW) model, logistic regression models with women undergoing their first IVF-ET cycle, and subgroup analysis. RESULTS: Of the 4780 women enrolled in the study, 3887 underwent an antagonist protocol for ovarian stimulation, while 893 received letrozole co-treatment. In this cohort, letrozole co-treatment demonstrated comparable live birth rates to the use of antagonist protocol alone (logistic regression: aOR, 0.88; 95% CI, 0.71-1.08; PSM: aOR, 0.97; 95% CI, 0.77-1.22; IPW: aOR, 0.88; 95% CI, 0.71-1.10). Notably, individuals with a body mass index (BMI) exceeding 24 and those with high ovarian response experienced higher live birth rates under the letrozole co-treatment regimen (BMI ≥ 24: aOR, 1.85; 95% CI, 1.14-3.00; high response: aOR, 1.60; 95% CI, 1.02-2.50). Letrozole co-treatment was also associated with decreased risks of gestational diabetes (aOR, 0.34; 95% CI, 0.15-0.69) and small for gestational age (SGA) fetuses (aOR, 0.42; 95% CI, 0.22-0.75) in fresh ET cycles. These finding were robust in both PSM and IPW models. CONCLUSIONS: Our findings suggested that letrozole co-treatment in antagonist protocol for IVF/ICSI was associated with a comparable live birth rate following fresh ET. Further prospective randomized studies are needed to verify our results.

Quantification of Letrozole, Palbociclib, Ribociclib, Abemaciclib, and Metabolites in Volumetric Dried Blood Spots: Development and Validation of an LC-MS/MS Method for Therapeutic Drug Monitoring.

Therapeutic drug monitoring (TDM) may be beneficial for cyclin-dependent kinase 4/6 inhibitors (CDK4/6is), such as palbociclib, ribociclib, and abemaciclib, due to established exposure-toxicity relationships and the potential for monitoring treatment adherence. Developing a method for quantifying CDK4/6is, abemaciclib metabolites (M2, M20), and letrozole in dried blood spots (DBS) could be useful to enhance the feasibility of TDM. Thus, an optimized LC-MS/MS method was developed using the HemaXis DB10 device for volumetric (10 µL) DBS collection. Chromatographic separation was achieved using a reversed-phase XBridge BEH C18 column. Detection was performed with a triple quadrupole mass spectrometer, utilizing ESI source switching between negative and positive ionization modes and multiple reaction monitoring acquisition. Analytical validation followed FDA, EMA, and IATDMCT guidelines, demonstrating high selectivity, adequate sensitivity (LLOQ S/N ≥ 30), and linearity (r ≥ 0.997). Accuracy and precision met acceptance criteria (between-run: accuracy 95-106%, CV ≤ 10.6%). Haematocrit independence was confirmed (22-55%),with high recovery rates (81-93%) and minimal matrix effects (ME 0.9-1.1%). The stability of analytes under home-sampling conditions was also verified. Clinical validation supports DBS-based TDM as feasible, with conversion models developed for estimating plasma concentrations (the reference for TDM target values) of letrozole, abemaciclib, and its metabolites. Preliminary data for palbociclib and ribociclib are also presented.

Trends and Regional Differences for Fertility Preservation Procedures in Women With Breast Cancer.

INTRODUCTION: Breast cancer is the most common malignancy in women of reproductive age and chemotherapy protocols impair fertility, frequently necessitating fertility preservation (FP) referral. Embryo, oocyte, or ovarian tissue cryopreservation are established FP modalities in women with breast cancer but there are few data on their uptake over time. In this study our aim was to determine the regional time trends and utility differences for fertility preservation methods of reproductive tissue cryopreservation. METHODS: This multicenter study included 1623 women diagnosed with breast cancer from 7 tertiary centers in 6 countries (Brazil, Italy, Scotland, South Korea, Turkey, USA). Participant centers provided the details of FP cryopreservation approaches broken down annually from 2012 to 2021. Women with newly diagnosed breast cancer, aged 18-45 years who were referred for FP at participating centers and had normal ovarian function at the time were included. RESULTS: We found a mean increase of 7% per year (P = .002, adjusting for centers) in the number of women referred for FP. Of those who were referred (n = 1623), a mean 38.7% underwent FP (n = 629), with a range of 12% in South Korea) to 95% in Brazil. The number of women undergoing ovarian stimulation for FP continually increased until 2021, with oocyte cryopreservation being the most common procedure throughout the study period (P = .014 for time trend). The proportion of random start ovarian stimulation cycles increased each year from 58.3% in 2012 to 86.8% in 2021, (P = .005 for time trend, and P = .04 for 2012 vs. 2021). CONCLUSIONS: The utility of FP has steadily increased for young women with breast cancer over the last decade, although regional differences significantly influence FP practices. The findings of our study could have value for policy making in FP care for young women with breast cancer at the local, regional, or global level.

Comparison between the levels of anti mullerian hormone after treatment with clomid versus letrozole in polycystic women: an experimental study.

OBJECTIVE: To compare the effect of two ovulation induction drugs on anti-Mullerian hormone level in polycystic women. METHODS: The experimental cohort study was done at the infertility outpatient clinics of Al-Yarmouk Teaching Hospital, Baghdad, Iraq, from May 2020 to April 2021, and comprised infertile women aged 18-35 years with confirmed diagnosis of polycystic ovarian syndrome. Baseline blood level of anti-Mullerian hormone was tested in all patients. The patients were divided into two groups. Group A patients received clomid 50mg twice daily to a maximum of 200mg for 5 days starting from the third day of the menstrual cycle. Group B patients received letrozole 2.5mg twice daily for 5 days starting from the third day of the menstrual cycle. After ovulation induction on day 12- 14, a second sample of serum anti-Mullerian hormone was tested, and intergroup comparisons were done. Data were analysed by using the available statistical package of SPSS-28 (Statistical Packages for Social Sciences- version 28). Students-t-test , Paired-t-test , Pearson correlation , t-test or ANOVA test Statistical significance was considered for P value equal or less than 0.05. RESULTS: Of the 83 women, 41(49.4%) were in Group A with mean age 26.0±4.9 years, while Group B had 42(50.6%) subjects with mean age 27.0±5.1 years. Post-intervention, the level of anti-Mullerian hormone decreased significantly in both groups (p<0.05). The decrease in Group B was more than Group A, but the difference was not significant (p>0.05). CONCLUSIONS: Ovulation induction drugs clomid and leterzole decreased the level of anti-Mullerian hormone significantly.

Can letrozole be repurposed for the treatment of visceral leishmaniasis?

Visceral leishmaniasis, caused by Leishmania infantum in New World countries, is the most serious and potentially fatal form of leishmaniasis, if left untreated. There are currently no effective prophylactic measures, and therapeutic options are limited. Therefore, we investigated whether the aromatase inhibitor letrozole (LET), which is already used to treat breast cancer, has an antileishmanial activity and/or immunomodulatory potential and therefore may be used to treat L. infantum infection. LET was active against L. infantum promastigote and amastigote life cycle stages in an in vitro infection model using human THP-1 cell-derived macrophages. In human peripheral blood leukocytes ex vivo, LET reduced the internalized forms of L. infantum by classical monocytes and activated neutrophils. Concomitantly, LET stimulated the production of IL-12/TNF-α and decreased the production of IL-10/TGF-ß by peripheral blood phagocytes, while in T and B cells, it promoted the production of TNF-α/IFN-γ and decreased that of IL-10. In a murine infection model, LET significantly reduced the parasite load in the liver after just 5 days and in the spleen after 15 days. During in vivo treatment with LET, the production of TNF-α/IFN-γ also increased. In addition, the proportion of developing granulomas decreased and that of mature granulomas increased in the liver, while there was no significant change in organ architecture in the spleen. Based on these data, repositioning of LET may be promising for the treatment of visceral leishmaniasis in humans.

Comparative analysis of hormonal therapy in low-grade endometrial stromal sarcoma: A retrospective study.

OBJECTIVE: To evaluate the disease course of patients with low grade endometrial stromal sarcoma (LG-ESS) and compare oncologic outcomes associated with hormonal therapy in primary and recurrent disease. METHODS: This is a retrospective study of patients with LG-ESS who underwent active treatment between January 2000 and July 2023. Recurrence-free survival (RFS) and overall survival (OS) were estimated using the Kaplan-Meier product-limit estimator and modeled via Cox proportional hazards regression. RESULTS: A total of 221 patients were included; 58 % of patients (91/157) were stage I, 12 % (19/157) stage II, 13 % (20/157) stage III, and 17 % (27/157) stage IV. Surgery was the primary treatment for 98 % (213/218). Only 79 patients received hormonal adjuvant therapy, 58 % (46/79) Megace, 24 % (19/79) Letrozole, and 18 % (14/79) received other hormonal therapy. There was no significant difference in RFS (p = 0.159) and OS (p = 0.167) between patients receiving Megace versus Letrozole as adjuvant therapy. At first recurrence, patients given Megace had a similar RFS to those on Letrozole (p = 0.302), but a better OS (27 vs 10 months, p = 0.018).  Negative status of estrogen, smooth muscle actin, and desmin were associated with lower RFS (p = 0.039, p = 0.002, and p = 0.015, respectively) and OS (p = 0.008, p = 0.012, and p = 0.013, respectively). Lymphovascular invasion was associated with lower RFS (p = 0.033), and negative status of progesterone was associated with lower OS (p = 0.003). CONCLUSION: There was no difference in oncologic outcomes between Megace and Letrozole in patients who received adjuvant therapy for LG-ESS. Megace may have potential survival advantage in recurrent disease. Further study is warranted to determine the most effective agents and their sequence in the treatment of LG-ESS.

Aromatase inhibitors can improve the semen quality of aged roosters by up regulating genes related to steroid hormone synthesis.

Excessive aromatase can reduce reproductive performance in aged roosters. Aromatase inhibitors (AI) can inhibit the aromatase activity and improve the semen quality of aged roosters. However, relevant molecular mechanism is still unclear. The purpose of this study was to explore the regulatory mechanism of AI letrozole improving semen quality in aged roosters by transcriptomic and proteomic sequencing. In this study, 56-week-old roosters were reared in separate cages on a standard basice diet and oral letrozole 42 days (D) at a daily dose 0.25 mg/kg. Semen quality and serum hormone were measured before (0 D) and after (42 D) letrozole administration. Reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) were detected, respectively. The results indicated that semen volume, sperm motility, sperm density, MMP, testosterone (T) and gonadotropin releasing hormone (GnRH) in letrozole treatment group (LET) were significantly increased than those in control group (CN) (P<0.05); estradiol (E2) and ROS in LET were significantly lower than those in CN (P<0.05). Through transcriptomic and proteomic analysis, we identified 189 differently expressed genes (DEGs) and 64 differentially expressed proteins (DEPs) in the comparison of LET and CN. DEGs and DEPs Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) items are mainly enriched in steroid biosynthetic process, cell differentiation and proliferation, lipid metabolic process, oxidation-reduction process and electron transfer activity. Furthermore, 8 genes including STAR, CYP17A1, NSDHL, SULT1E1, EHF, NRNPA1, PLIN2 and SDHA were identified as key genes for letrozole to regulate semen quality in aged roosters. These results indicate that letrozole can up-regulate the expression of genes related to steroid hormone synthesis, cell differentiation and proliferation, electron transfer activity, and enhance mitochondrial activity, increase testicular weight, and ultimately improve the semen quality of aged roosters.

The Effectiveness of Letrozole Alone or in Combination with Methotrexate in the Management of Ectopic Pregnancy, A Systematic Review and Meta-Analysis.

This systematic review and meta-analysis aimed to investigate the effect of letrozole alone or in combination with Methotrexate on the management of ectopic pregnancy. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) were applied for reporting. The EMBASE, PubMed, Scopus, and Web of Science databases were searched for relevant studies focused on women diagnosed with ectopic pregnancy and managed non-surgically with letrozole alone or in combination with methotrexate (MTX) until April 2024. The success rate, laboratory findings, and complications were analyzed and reported. Meta-analysis was done using RevMan 5.4.1 software. Out of 129 unique studies obtained, 7 of them were found eligible for final review; of which, 3 were nonrandomized prospective cohort studies, 2 were randomized clinical trials, and 2 study were case studies. In 5 studies letrozole was used as monotherapy. While in another study letrozole was used with MTX. The meta-analysis showed a significantly lower level of ß-HCG in the letrozole group compared to MTX, 7 days after initiation of treatment (Fixed effect model, MD = -92.22, 95%CI: [-159.39, -25.04], P = 0.007, I2 = 0%). There was no significant difference in the level of anti-mullerian hormone (AMH) between groups (Fixed effect model, MD = 0.18, 95%CI: [-0.09, 0.45], P = 0.20, I2 = 0%). Success rate, platelet count, and level of liver enzymes seemed to be better or similar among patients receiving Letrozole compared to patients receiving Methotrexate. Letrozole exhibits potential as a therapeutic option for ectopic pregnancies; however, further randomized clinical trials are necessary to establish strong evidence.

Monocyte subsets in breast cancer patients under treatment with aromatase inhibitor and mucin-1 cancer vaccine.

BACKGROUND: Monocytes comprise subsets of classical, intermediate and non-classical monocytes with distinct anti- or pro-tumor effects in breast cancer (BC). They are modulated by estrogen, and can contribute to BC control by endocrine therapy in preclinical models. METHODS: To elucidate whether changes in monocyte subsets are associated with treatment and response, we investigated peripheral blood samples of 73 postmenopausal women with estrogen receptor (ER) positive BC, who received aromatase inhibitor therapy with or without the mucin-1 vaccine tecemotide in the ABCSG34 trial. Blood was retrieved at baseline, midterm and end of therapy, and was analyzed for the distribution and ER expression of monocyte subsets by flow cytometry. RESULTS: When 40 healthy, age-matched women were compared with BC patients before treatment start, ER levels of monocytes did not differ, yet patients presented with a higher frequency of classical and fewer non-classical monocytes. Endocrine therapy triggered a significant increase in ER levels in all monocyte subsets, without affecting subset distribution. Vaccination had no overall impact on subset frequency and ER expression. Yet, a shift from intermediate to classical monocytes during therapy correlated with changes in plasma cytokines and chemokines and was significantly associated with low residual cancer burden in vaccinated patients. Without tecemotide, baseline ER levels in classical monocytes were significantly higher in women with good response to endocrine therapy. CONCLUSIONS: This study identified classical monocytes to be associated with ER positive BC and with patient response to neoadjuvant endocrine treatment and cancer vaccination.

Histological features of the Purkinje neurons of the Albino rat (Rattus norvegicus) following letrozole administration.

Aromatase inhibitors are increasingly being used as adjuvant therapy for hormone-responsive cancers. These drugs may reduce the endogenous estrogen production in the cerebellum. Prolonged use has been associated with symptoms such as ataxia, poorer balance performance and diminished verbal memory, suggesting impaired cerebellar function. Thus, this study sought to outline the structural basis for the cerebellar deficits observed. Twenty-seven male rats (3 baseline, 15 experimental, 9 control) aged three months were recruited with the intervention group receiving 0.5 mg/kg of letrozole daily for 50 days by oral gavage while the control group received normal saline. Their cerebella were harvested for histological processing on days 20, 35, and 50. Photomicrographs were taken and analysed using Fiji ImageJ software. The dendritic spine densities and Purkinje linear densities were coded and analyzed using IBM SPSS Statistics version 25.0. A P-value of ≤0.05 was considered significant. A temporal decline in the Purkinje linear density as well as pyknosis and cytoplasmic eosinophilia was noted in the intervention group (P=0.1). Further, the dendritic spine density of the Purkinje neurons in the intervention group was markedly reduced (P=0.01). The reduction in the linear cell density and the dendritic spine density of the Purkinje cells following letrozole administration may provide an anatomical basis for the functional cerebellar deficits seen in chronic aromatase inhibitor use.

Neoadjuvant letrozole and palbociclib in patients with HR-positive/HER2-negative early breast cancer and Oncotype DX Recurrence Score ≥18: DxCARTES study.

BACKGROUND: The effect of the addition of cyclin-dependent kinases 4 and 6 inhibitors to endocrine therapy in terms of molecular downstaging remains undetermined. Switching from a high-risk to a low risk Recurrence Score (RS) group could provide useful information to identify patients who might not require chemotherapy. The purpose of this study was to assess the biological and clinical activity of letrozole plus palbociclib as neoadjuvant treatment for patients with hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative early breast cancer with an initial Oncotype DX RS ≥18. PATIENTS AND METHODS: Participants were women aged ≥18 years with HR-positive/HER2-negative, Ki67 ≥ 20%, stage II-IIIB early breast cancer with a baseline RS ≥18. Eligible patients with a pretreatment RS 18-25 (cohort A) and 26-100 (cohort B) received six 28-day cycles of letrozole (2.5 mg per day; plus goserelin if pre- or perimenopausal) plus palbociclib (125 mg per day; 3/1 schedule) before surgery. The primary endpoint for both cohorts was the proportion of patients who achieved an RS ≤25 at surgery or a pathological complete response (pCR). RESULTS: A total of 67 patients were enrolled, among which 65 were assessable for the primary endpoint (32 patients in cohort A and 33 in cohort B). At surgery, 22 (68.8%) patients in cohort A and 18 (54.5%) patients in cohort B had an RS ≤25 or a pCR [only 1 (3.0%) patient in cohort B], meeting the primary endpoint in cohort B (P < 0.01), but not in cohort A (P = 0.98). No new safety signals were identified. CONCLUSIONS: The efficacy of neoadjuvant treatment with letrozole plus palbociclib does not seem to depend on pretreatment RS for patients with RS ≥18. However, around half of patients with HR-positive/HER2-negative early breast cancer with an RS 26-100 at baseline achieved molecular downstaging with this regimen.

Anastrozole vs Letrozole to Augment Height in Pubertal Males With Idiopathic Short Stature: A 3-Year Randomized Trial.

Context: Insufficient efficacy and safety data for off-label use of aromatase inhibitors to augment height in boys with short stature. Objective: To compare anastrozole and letrozole in treatment of idiopathic short stature in pubertal boys. Design: Open-label trial with 2 treatment arms. Setting: Pediatric Endocrine Clinic at Stanford. Participants: A total of 79 pubertal males ≥10 years with bone age (BA) ≤ 14 years, predicted adult height (PAH) < 5th percentile or >10 cm below mid-parental height. Intervention: Anastrozole 1.0 mg or letrozole 2.5 mg daily for up to 3 years. Main Outcome Measures: Annual hormone levels and growth parameters during treatment and a year posttherapy; annual BA and PAH (primary outcome measure); spine x-rays and dual energy X-ray absorptiometry at baseline and 2 years. Results: Compared with anastrozole (n = 35), letrozole (n = 30) resulted in higher testosterone levels, lower estradiol and IGF-1 levels, and slower growth velocity and BA advance. The PAH increase observed at year 1 in both groups did not persist at years 2 and 3. Change in PAH from baseline was not different between treatment groups. In groups combined, PAH gain over 3 years vs baseline was +1.3 cm (P = .043) in linear mixed models. Conclusion: Letrozole caused greater deviations than anastrozole in hormone levels, growth velocity, and BA advancement, but no group differences in PAH or side effects were found. Change in PAH after 2 to 3 years of treatment was minimal. The efficacy of AI as monotherapy for height augmentation in pubertal boys with idiopathic short stature may be limited, and safety remains an issue.

Effectiveness of Acupuncture for Infertility in Patients with Polycystic Ovary Syndrome: A Systematic Review and Network Meta-Analysis.

OBJECTIVE: This study employs a network meta-analysis method to investigate the clinical effectiveness of acupuncture in patients with polycystic ovary syndrome (PCOS) experiencing infertility. METHODS: Prospective randomized controlled trials (RCTs) of clomiphene citrate (CC) and letrozole (LE) combined with acupuncture in PCOS infertility patients were identified through computerized searches in databases including PubMed, Web of Science, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang Data, and Chongqing VIP Database. The search period was set from inception until August 1, 2023, with no language restrictions. Two researchers screened articles, extracted data, and independently assessed the risk of bias in eligible trials. Data were analyzed and visualized using the R software gemtc package. With patients with medication treatment only set as controls, a meta-analysis was performed to investigate the difference in the pregnancy outcomes of the PCOS patients following medication amalgamated with different acupuncture treatments, namely, manual acupuncture (MA), electroacupuncture (EA), and warm acupuncture (WA). RESULTS: The serum concentrations of follicle-stimulating hormone (FSH) did not exhibit significant changes following acupuncture treatments. Notably, acupuncture-based medication treatment significantly reduced serum levels of luteinizing hormone (LH) and elevated the testosterone (T) concentrations of patients when compared to medication treatment alone. Patients also showed significantly escalated serum estradiol (E2) levels after receiving CC integrated with acupuncture than those given monotherapy of CC. The combined regimen of medication and acupuncture appeared to improve the pregnancy outcomes compared to the monotherapy of medication, as evidenced by the significantly increased success rate of pregnancy. Furthermore, the treatment combination of CC plus WA and LE plus MA yielded the highest probability of achieving the best pregnancy outcomes. CONCLUSION: For PCOS infertility patients, acupuncture, as a complementary treatment to CC and LE, holds advantages in improving reproductive hormone levels and enhancing pregnancy success rates. The highest probability of achieving the best pregnancy outcomes is associated with the treatment combination of CC with WA and LE with MA.

Letrozole-induced reversible acute heart failure.

INTRODUCTION: Letrozole is an aromatase inhibitor (AI), which suppresses plasma estrogen levels by inhibiting the aromatase enzyme, that causes the conversion of androgens to estrogen in peripheral tissues. There is very few information in the literature regarding the development of acute heart failure after AI use. We would like to report a case of a patient who was started letrozole for hormonal treatment and developed acute heart failure due to this. CASE REPORT: Fifty-seven-year-old woman with hormone positive breast cancer was operated after neoadjuvant chemotherapy and received radiotherapy. Letrozole treatment was initiated after radiotherapy and the patient presented to the emergency department after two weeks with cough and dyspnea. Ejection fraction decreased to 20% and acute heart failure developed. MANAGEMENT AND OUTCOME: Letrozole treatment was stopped. Afterwards, improvement in the patient's cardiac functions was observed. Letrozole-induced heart failure was thought to be reversible. DISCUSSION: Letrozole is one of the most commonly used HT in the treatment of hormone positive breast cancer. It may rarely cause cardiac side effects. It is very important to make patients aware of these issues and to be consulted by cardiology in case of possible cardiac symptoms.

Patuletin Ameliorates Inflammation and Letrozole-Induced Polycystic Ovarian Syndrome in Rats.

Concerns about inflammation-related issues affecting female reproductive health are growing. Chronic low-grade inflammation in women with polycystic ovarian syndrome (PCOS) affects follicular growth, ovulation, and androgen production. The present investigation aimed to elucidate the efficacy of flavonoid patuletin in ameliorating the letrozole-induced PCOS and associated inflammation in rats. Female Wistar rats (32 days old) were divided into five groups (n = 12): Group I, control; Group II, vehicle control; Group III, letrozole oral (1 mg/kg) for 28 days; Group IV and Group V treatment groups, patuletin i.p. (25 mg/kg) and clomiphene citrate + metformin i.p. (50 mg/kg + 300 mg/kg), respectively. Leterozole-induced PCOS and ovarian inflammation were ameliorated by patuletin, as reflected in the improved histopathology, prevention of cyst formation, significant upregulation of growth factors such as growth differentiation factor 9 (GDF-9) and bone morphogenetic protein-15 (BMP-15) expression, and a decrease in the pro-inflammatory cytokines TNF-α, IL-6, and COX-2. Additionally, the plasma levels of reproductive hormones were restored. Upregulation of FSH-R, PR, and CYP19a1, along with downregulation of ERα, LHR, CYP17a1, CYP11a1 and HSDß17a1, showed the regulation of gonadotropin receptors and steroid biosynthesis genes in ovarian tissues. Patuletin demonstrated a promising protective approach against the biological model of PCOS by increasing the inflammation in ovarian tissues with consequent regulation of growth factors, enzymes, and hormones, and might be used as adjuvant therapy in the treatment of problems related to female reproductive health.

Intelligence computational analysis of letrozole solubility in supercritical solvent via machine learning models.

Supercritical fluids (SCFs) can be used to prepare drugs nanoparticles with improved solubility. SCFs have shown superior advantages in pharmaceutical industry as an environmentally friendly alternative to toxic/harmful organic solvents. They possess gas-like transport characteristics and liquid-like solvation power for solutes. Evaluation of chemotherapeutic drugs' solubility in supercritical carbon dioxide (SCCO2) has been recently an attractive subject for developing this method in pharmaceutical sector. To reach this purpose, the utilization of accurate models is of great necessity to estimate experimental-based solubility data. In this paper, the authors tried to employ machine learning (ML) approaches to estimate the solubility of Letrozole (LET) drug as chemotherapeutic agent and correlate its values in wide ranges of temperature and pressure. To do this, PAR (Passive Aggressive Regression), RF (Random Forest), and RBF-SVM are the models used (Support Vector Machine with RBF kernel). These models optimized in terms of their hyper-parameters using GA algorithm. The optimized PAR, RF, RBF-SVM models obtained coefficients of determination (R-squared) of 0.8277, 0.9534, and 0.9947. Also, the MSE error rate of the models are 0.1342, 0.0305, and 0.0045, in the same order. The final result of the evaluations shows the optimized RBF-SVM model as the most appropriate model in this research. The model exhibits a maximum prediction error of 0.1289.

Off-label letrozole for tubal pregnancy monotherapy is not an alternative to methotrexate: a prospective cohort study.

OBJECTIVES: Inhibition of estradiol production by letrozole may interfere with physiological effects of progesterone necessary to maintain the pregnancy. Treatment of tubal pregnancy (TP) with letrozole would allow to avoid the disadvantages of methotrexate (MTX). The aim was to compare the effectiveness of letrozole with MTX in the management of TP. MATERIAL AND METHODS: A prospective open-label cohort study was conducted among women with TP and increasing B-human chorionic gonadotropin (B-hCG) concentrations. MTX was administered in a single dose of 100 mg intravenously, while letrozole in a dose of 5 mg orally for 10 days. Blood parameters (B-hCG, hemoglobin, creatinine, urea, transaminases, bilirubin) were tested on days 0, 4 and 7. RESULTS: Out of 22 eligible women, 14 received MTX and received 8 letrozole. Mean age, lesion diameter, gestation age in the MTX vs letrozole arm were: 31 vs 32 years (p = 0.3), 13.2 vs 16.3 mm (p = 0.1), 7 + 1 vs 7 + 0 weeks (p = 0.6), respectively. In case of 4 women treated with letrozole and in 2 treated with MTX (4/8, 50% vs 2/14, 14.3%, p = 0.07) the treatment was unsuccessful. There were no significant differences in blood parameters on days 0, 4 and 7 between both arms, except for the increasing urea concentration in the letrozole arm (p = 0.01). CONCLUSIONS: Even though the results did not reach statistical significance, it is likely that a larger study sample would confirm the trend of letrozole being less effective. The results did not support the use of letrozole in the studied regimen as an alternative to MTX.