HER2/neu 655 polymorphism, trastuzumab-induced cardiotoxicity, and survival in HER2-positive breast cancer patients.

PURPOSE: HER2 overexpression in breast cancer correlates with poor outcomes. The incorporation of Trastuzumab into the treatment regimen has notably improved patient prognoses. However, cardiotoxicity emerges in approximately 20% of patients treated with the drug. This study aims to investigate the association between the HER2 655 A > G polymorphism, Trastuzumab-induced cardiotoxicity, and patient survival. METHODS: The study involved 88 patients treated with Trastuzumab. Cardiotoxicity, defined as a reduction in left ventricular ejection fraction (LVEF) from baseline or the emergence of clinical signs of congestive heart failure, was identified during treatment follow-up. Genotyping of HER2 655 A > G employed TaqMan SNP technology. RESULTS: Genotype frequencies of HER2/neu 655 (53 AA, 32 AG, and 3 GG) were consistent with Hardy-Weinberg equilibrium. No significant differences were observed in mean baseline LVEF between patients who developed cardiotoxicity and those who did not. Within these groups, neither AA nor AG genotypes showed an association with changes in mean baseline or reduced LVEF levels. Logistic regression analysis, adjusted for hormonal status and anthracycline treatment, revealed that AG genotype carriers face a significantly higher risk of cardiotoxicity compared to AA carriers (OR = 4.42; p = 0.037). No association was found between the HER2/neu 655 A > G polymorphism and disease-free or overall survival, regardless of whether the data was adjusted for stage or not. CONCLUSION: HER2 655 A > G polymorphism is significantly linked to an increased risk of Trastuzumab-induced cardiotoxicity but does not correlate with variations in disease-free survival or overall survival rates.

Discovery of a synthetic taiwaniaquinoid with potent in vitro and in vivo antitumor activity against breast cancer cells.

Taiwaniaquinoids are a unique family of diterpenoids predominantly isolated from Taiwania cryptomerioides Hayata. Previously, we evaluated the antiproliferative effect of several synthetic taiwaniaquinoids against human lung (A-549), colon (T-84), and breast (MCF-7) tumor cell lines. Herein, we report the in vitro and in vivo antitumor activity of the most potent compounds. Their cytotoxic activity against healthy peripheral blood mononuclear cells (PBMCs) has also been examined. We underscore the limited toxicity of compound C36 in PBMCs and demonstrate that it exerts its antitumor effect in MCF-7 cells (IC50 = 1.8 µM) by triggering an increase in reactive oxygen species, increasing the cell population in the sub-G1 phase of the cell cycle (90 %), and ultimately activating apoptotic (49.6 %) rather than autophagic processes. Western blot results suggested that the underlying mechanism of the C36 apoptotic effects was linked to caspase 9 activation and a rise in the Bax/Bcl-2 ratio. In vivo analyses showed normal behavior and hematological parameters in C57BL/6 mice post C36 treatment. Moreover, no significant impact was observed on the biochemical parameters of these animals, indicating that C36 did not induce liver toxicity. Furthermore, C36 demonstrated a significant reduction in tumor growth in immune-competent C57BL/6 mice implanted with E0771 mouse mammary tumor cells, effectively improving survival rates. These findings position taiwaniaquinoids, particularly compound C36, as promising therapeutic candidates for human breast cancer.

Early increase in tamoxifen dose in CYP2D6 poor metaboliser breast cancer patients and survival: A propensity score matching analysis.

PURPOSE: Tamoxifen is a drug used for hormone receptor-positive breast cancers, primarily metabolised by the CYP2D6 enzyme into active metabolites such as endoxifen. CYP2D6 displays varying degrees of activity depending on its genotype. This study aims to analyse the effect of an early increase in tamoxifen dose in poor metabolisers (PM) on survival. METHODS: We enrolled 220 patients diagnosed with breast cancer who were treated with tamoxifen. CYP2D6 polymorphisms were determined, and the phenotype was estimated according to the Clinical Pharmacogenetics Implementation Consortium. Disease-free survival (DFS) and overall survival (OS) were analysed considering the entire patient group, and a subgroup of 110 patients selected by Propensity Score Matching (PSM). All women were treated with 20 mg/day of tamoxifen for 5 years, except PM, who initially received 20 mg/day for 4 months, followed by 40 mg/day for 4 months and 60 mg/day for 4 months before returning to the standard dose of 20 mg/day until completing 5 years of treatment. RESULTS: The analysis of the influence of CYP2D6 polymorphisms in the complete group and in the PSM subgroup revealed no significant differences for DFS or OS. Furthermore, DFS and OS were analysed in relation to various covariates such as age, histological grade, nodal status, tumour size, HER-2, Ki-67, chemotherapy, and radiotherapy. Only age, histological grade, nodal status, and chemotherapy treatment demonstrated statistical significance. CONCLUSION: An early increase in tamoxifen dose in PM patients is not associated with survival differences among CYP2D6 phenotypes.

Endovascular Technique for Ascending Aorta Repair Based on TEVAR and TAVI Procedures.

PURPOSE: Ascending aorta (AAo) acute pathology still has an open-surgery indication with a high mortality rate associated to cardiopulmonary bypass and circulatory arrest. In these cases, the endovascular aortic approach could be an excellent option. The aim of the present study is to detail an optimized technique for the endovascular treatment of AAo diseases, based on thoracic endovascular aortic repair (TEVAR) and transcatheter aortic valve implantation (TAVI) procedures. TECHNIQUE: The procedure implies the usual preparation for TEVAR and TAVI implants. A transient pacemaker lead is necessary to deliver the prosthesis under "rapid pacing." As in the TAVI technique, a final high-support guidewire is placed at the left ventricle. The proximal landing zone is the sinotubular junction (zone 0B). Transesophageal echocardiography is essential to ensure aortic valve function and patency in coronary arteries during the delivery. To assess a potential occlusion of the brachiocephalic artery, a guidewire is positioned in the descending aorta from the axillary artery. Finally, a noncovered stent is implanted to stabilize the AAo prosthesis. CONCLUSION: The technique presented here can standardize a safe and reproducible procedure to endovascular repair of AAo diseases. However, new devices specifically designed for the AAo could facilitate the transcatheter approach. CLINICAL IMPACT: Ascending aorta acute pathology still has an open-surgery indication with high mortality rate associated to cardiopulmonary bypass and circulatory arrest. Moreover, near 30% of patients are not considered suitable for surgery because of age, critical situation or the presence of severe comorbidities. The present study provides a detailed and optimized technique for the endovascular treatment of ascending aorta disease, based on TEVAR and TAVI procedures.

NT-proBNP as predictor factor of cardiotoxicity during trastuzumab treatment in breast cancer patients.

BACKGROUND: Trastuzumab is a drug used in HER2-positive breast cancer that increases patient survival. Due to cardiotoxicity is the most important side effect of trastuzumab treatment, cardiac monitoring should be a priority. The purpose of this study is to evaluate plasma NT-proBNP level and major cardiovascular risk factors as possible early predictors of trastuzumab-induced cardiotoxicity in HER2-positive breast cancer patients. METHODS: We conducted a retrospective observational study involving 66 patients with HER2-positive breast cancer treated with trastuzumab. Left ventricle ejection fraction (LVEF), NT-proBNP values, and the history of cardiovascular risk factors were collected. Cardiotoxicity was diagnosed considering a decrease of the LVEF from baseline or clinical manifestation of congestive heart failure. NT-proBNP cut-off points were considered to establish normal or abnormal values according to patient age. RESULTS: 27.3% of the patients suffered cardiotoxicity during trastuzumab treatment. Most cases were diagnosed due to the appearance of cardiac symptomatology (66.7%). Logistic regression analysis showed a significant association of diabetes mellitus (OR 5.9, 95% CI 1.2-28.5, p = 0.028) and high NT-proBNP levels (OR 22.0, 95% CI 5.7-85.4, p < 0.0001) with the development of trastuzumab-induced cardiotoxicity. CONCLUSION: NT-proBNP levels above the upper limit of the normal range adjusted to age or diabetes mellitus seem to be associated with a higher risk of developing cardiotoxicity. However, some limitations of the present study make necessary further studies aimed to clarify whether NT-proBNP and diabetes-associated markers determinations can be useful in the monitoring of cardiotoxicity risk in breast cancer patients undergoing trastuzumab therapy.

Immunophenotypic Conversion between Primary and Relapse Breast Cancer and its Effects on Survival.

BACKGROUND: The differential expression of oestrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor 2 (HER2) or Ki-67 between primary tumour and the recurrence has been described. We aimed to determine these changes and their prognostic implications. PATIENTS AND METHODS: We retrospectively reviewed 45 breast cancer patients with relapsed biopsy that were classified into local relapse (LR) or metastatic disease (MD) groups. We analyzed the conversion rate and the value of the immunophenotype of the primary tumour and the relapse as a prognostic factor for relapse-free survival (RFS), progression-free survival (PFS) and overall survival (OS). RESULTS: The conversion rate was 34.8% for Ki-67, 20% for ER, 20% for PR, and 15.6% for HER2. For the LR group, the RFS was 71.9 months and the OS was 141.6 months, without statistical differences according to the immunophenotype of the primary or the relapsed biopsy. For the MD group, the PFS was 20.8 months. According to immunophenotype of the relapse, the PFS were ER+ 24.7 months vs. ER- 9.3 months; PR+ 25.1 months vs. PR- 12.7 months without statistical differences according to HER2 or Ki67. The OS for MD group was 54.4 months without statistical differences according to immunophenotype. CONCLUSION: The characteristics of breast cancer can change over the time. Variations of the ER or PR status in MD group have prognostic value for PFS. To perform a biopsy of relapses is warranted in order to establish the prognostic of the current disease, and probably a more accurate treatment.

Intermuscular S-ICD Implantation in Pediatric Patients.

The use of conventional implantable cardioverter-defibrillators (ICDs) in children presents important technical challenges. We present the surgical technique necessary to adapt the subcutaneous ICD (S-ICD) implantation designed for adults, to children, including patients weighing less than 20 kg. The implant procedure implies a two-incision technique and interfascial serratus anterior-latissimus dorsi dissection to accommodate the device. S-ICD implantation was successfully performed in three patients of 19, 28, and 24 kg, respectively, two of them suffered cardiorespiratory arrest. Intermuscular thoracic implantation of S-ICD might represent an effective strategy for primary or secondary prevention of sudden cardiac death in pediatric patients.

Hearing regeneration and regenerative medicine: present and future approaches.

More than 5% of the world population lives with a hearing impairment. The main factors responsible for hearing degeneration are ototoxic drugs, aging, continued exposure to excessive noise and infections. The pool of adult stem cells in the inner ear drops dramatically after birth, and therefore an endogenous cellular source for regeneration is absent. Hearing loss can emerge after the degeneration of different cochlear components, so there are multiple targets to be reached, such as hair cells (HCs), spiral ganglion neurons (SGNs), supporting cells (SCs) and ribbon synapses. Important discoveries in the hearing regeneration field have been reported regarding stem cell transplantation, migration and survival; genetic systems for cell fate monitoring; and stem cell differentiation to HCs, SGNs and SCs using adult stem cells, embryonic stem cells and induced pluripotent stem cells. Moreover, some molecular mediators that affect the establishment of functional synapses have been identified. In this review, we will focus on reporting the state of the art in the regenerative medicine field for hearing recovery. Stem cell research has enabled remarkable advances in regeneration, particularly in neuronal cells and synapses. Despite the progress achieved, there are certain issues that need a deeper development to improve the results already obtained, or to develop new approaches aiming for the clinical application.

Extracellular vesicles of Trypanosoma cruzi tissue-culture cell-derived trypomastigotes: Induction of physiological changes in non-parasitized culture cells.

BACKGROUND: Trypanosoma cruzi is the obligate intracellular parasite that causes Chagas disease. The pathogenesis of this disease is a multifactorial complex process that involves a large number of molecules and particles, including the extracellular vesicles. The presence of EVs of T. cruzi was first described in 1979 and, since then, research regarding these particles has been increasing. Some of the functions described for these EVs include the increase in heart parasitism and the immunomodulation and evasion of the host immune response. Also, EVs may be involved in parasite adhesion to host cells and host cell invasion. METHODOLOGY/PRINCIPAL FINDINGS: EVs (exosomes) of the Pan4 strain of T. cruzi were isolated by differential centrifugation, and measured and quantified by TEM, NTA and DLS. The effect of EVs in increasing the parasitization of Vero cells was evaluated and the ED50 was calculated. Changes in cell permeability induced by EVs were evaluated in Vero and HL-1 cardiomyocyte cells using cell viability techniques such as trypan blue and MTT assays, and by confocal microscopy. The intracellular mobilization of Ca2+ and the disruption of the actin cytoskeleton induced by EVs over Vero cells were followed-up in time using confocal microscopy. To evaluate the effect of EVs over the cell cycle, cell cycle analyses using flow cytometry and Western blotting of the phosphorylated and non-phosphorylated protein of Retinoblastoma were performed. CONCLUSION/SIGNIFICANCE: The incubation of cells with EVs of trypomastigotes of the Pan4 strain of T. cruzi induce a number of changes in the host cells that include a change in cell permeability and higher intracellular levels of Ca2+ that can alter the dynamics of the actin cytoskeleton and arrest the cell cycle at G0/G1 prior to the DNA synthesis necessary to complete mitosis. These changes aid the invasion of host cells and augment the percentage of cell parasitization.

Left superior vena cava draining into the left atrium: Clinical entities, diagnosis and surgical treatment.

Left superior vena cava draining into the left atrium in the absence of coronary sinus is an anomaly that can appear in heterotaxy syndrome and unroofed coronary sinus syndrome. Regardless of the origin of these syndromes, biventricular repair can be done through rerouting by intracardiac procedures or through disconnection-reconnection of the left superior vena cava to the right atrium or right superior vena cava by extracardiac procedures. Different techniques can be used for this purpose, each of which has its own advantages and limitations. Therefore, appropriate selection is necessary to obtain the best results for each patient, and many factors, such as patient anatomy, age, associated cardiomyopathies, etc., have to be considered. In this review, we focus on heterotaxy and unroofed coronary sinus syndromes, associated cardiomyopathies, the state-of-the-art in their surgical treatment and our results in a sample of 10 patients. Our experience highlights the importance of accurate diagnosis and specific selection of surgical technique for the management of biventricular repair in patients with left superior vena cava draining into the left atrium in the absence of coronary sinus.

Biological Evaluation and Docking Studies of Synthetic Oleanane-type Triterpenoids.

Saponins are potential wide-spectrum antitumor drugs, and copper(I) catalyzed azide-alkyne 1,3-dipolar cycloaddition is a suitable approach to synthesizing saponin-like compounds by regioselective glycosylation of the C2/C3 hydroxyl and C28 carboxylic groups of triterpene aglycones maslinic acid (MA) and oleanolic acid (OA). Biological studies on the T-84 human colon carcinoma cell line support the role of the hydroxyl groups at C2/C3, the influence of the aglycone, and the bulky nature of the substituents in C28. OA bearing a α-d-mannose moiety at C28 (compound 18) focused our interest because the estimated inhibitory concentration 50 was similar to that reported for ginsenoside Rh2 against colon cancer cells and it inhibits the G1-S phase transition affecting the cell viability and apoptosis. Considering that triterpenoids from natural sources have been identified as inhibitors of nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) signaling, docking studies were conducted to evaluate whether NF-κB may be a potential target. Results are consistent with the biological study and predict a similar binding mode of MA and compound 18 to the p52 subunit from NF-κB but not for OA. The fact that the binding site is shared by the NF-κB inhibitor 6,6-dimethyl-2-(phenylimino)-6,7-dihydrobenzo[d][1,3]oxathiol-4(5H)-one supports the result and points to NF-κB as a potential target of both MA and compound 18.

Synthesis and antiproliferative activity of podocarpane and totarane derivatives.

The synthesis of podocarpanes, including 12,19-dihydroxy-13-acetyl-8,11,13-podocarpatriene (23), isolated from Gaultheria yunnanensis and not previously synthesized, and totarane-type terpenoids, starting from the natural labdane trans-communic acid (15), is described. Their antiproliferative activities against MCF-7, T-84 and A-549 human tumoural cell lines are studied. An antiproliferative effect was induced by compounds 23, 27 and 28, with IC50 < 10 µM in two (27) or three cell lines (23 and 28). No correlation with log P values was observed. The totarane o-quinone 27, and especially the catechol 28, which is readily oxidisable to compound 27, were the most active compounds, highlighting the functional groups present in C11 and C12. Compound 28 showed limited toxicity in normal peripheral blood mononuclear cells (78.5% cell viability versus non-treated control cultures at 10 µM), and appeared to exert an antiproliferative effect in A-549 cells (IC50 0.6 µM) through a mechanism that involves the induction of apoptosis mediated by an increased Bax/Bcl-2 ratio. The results of the present study indicate that compound 28, at least, might be useful as an antitumoral agent. Further studies are required to elucidate the cellular and molecular elements involved in its effect, and the activity/toxicity in preclinical models.

The role of exosomes on colorectal cancer: A review.

Exosomes are extracellular microvesicles released from cells, which are involved in many biological and pathological processes, mainly because of their role in intercellular communication. Exosomes derived from colorectal cancer (CRC) cells are related to oncogenesis, tumor cell survival, chemo-resistance, and metastasis. The role of the exosomes in these processes involves the transfer of proteins, RNAs, or mutant versions of proto-oncogenes to the target cells. In recent years, great efforts have been made to identify useful biomarkers in CRC exosomes for diagnosis, prediction of prognosis, and treatment response. This review focuses on recent studies on CRC exosomes, considering isolation, cargo, biomarkers, and the effects of exosomes on the development and progression of CRC, including resistance to antitumor therapy.

Antiproliferative Activity of Natural Taiwaniaquinoids and Related Compounds.

The in vitro antiproliferative activities of some taiwaniaquinoids and related compounds with functionalized A, B, or C rings against human breast (MCF-7), colon (T-84), and lung (A-549) tumor cell lines were assayed. The most potent compounds, 16, 27, and 36, were more effective than the naturally occurring taiwaniaquinones A (4) and F (5) in all three cell lines. The structure-activity relationship study of these new taiwaniaquinoids highlighted the correlation between the bromo substituent and the antiproliferative activity, especially in MCF-7 cells. These findings indicate that some of the taiwaniaquinoids might be useful as cytostatic agents against breast, colon, and lung cancer cell lines.

Functionalized immunostimulating complexes with protein A via lipid vinyl sulfones to deliver cancer drugs to trastuzumab-resistant HER2-overexpressing breast cancer cells.

BACKGROUND: Around 20%-30% of breast cancers overexpress the proto-oncogene human epidermal growth receptor 2 (HER2), and they are characterized by being very invasive. Therefore, many current studies are focused on testing new therapies against tumors that overexpress this receptor. In particular, there exists major interest in new strategies to fight breast cancer resistant to trastuzumab (Tmab), a humanized antibody that binds specifically to HER2 interfering with its mitogenic signaling. Our team has previously developed immunostimulating complexes (ISCOMs) as nanocapsules functionalized with lipid vinyl sulfones, which can incorporate protein A and bind to G immunoglobulins that makes them very flexible nanocarriers. METHODS AND RESULTS: The aim of this in vitro study was to synthesize and evaluate a drug delivery system based on protein A-functionalized ISCOMs to target HER2-overexpressing cells. We describe the preparation of ISCOMs, the loading with the drugs doxorubicin and paclitaxel, the binding of ISCOMs to alkyl vinyl sulfone-protein A, the coupling of Tmab, and the evaluation in both HER2-overexpressing breast cancer cells (HCC1954) and non-overexpressing cells (MCF-7) by flow cytometry and fluorescence microscopy. Results show that the uptake is dependent on the level of overexpression of HER2, and the analysis of the cell viability reveals that targeted drugs are selective toward HCC1954, whereas MCF-7 cells remain unaffected. CONCLUSION: Protein A-functionalized ISCOMs are versatile carriers that can be coupled to antibodies that act as targeting agents to deliver drugs. When coupling to Tmab and loading with paclitaxel or doxorubicin, they become efficient vehicles for the selective delivery of the drug to Tmab-resistant HER2-overexpressing breast cancer cells. These nanoparticles may pave the way for the development of novel therapies for poor prognosis resistant patients.

Meroxest improves the prognosis of immunocompetent C57BL/6 mice with allografts of E0771 mouse breast tumor cells.

INTRODUCTION: Recently, we have reported the antitumor properties of a new family of synthetic merosesquiterpenes, among which meroxest is highlighted, since it has high activity and specificity for ER+ breast cancer cells. In this paper, we characterize allografts of ER+ E0771 mouse breast tumor cells in immunocompetent C57BL/6 mice, and also analyze the effect of meroxest on the prognosis of the disease. MATERIAL AND METHODS: Twenty female C57BL/6 mice were injected with 106 E0771 cells. Once the tumors reached the appropriate size, the mice were divided into two groups, one control and another treated orally with 15 mg/kg of meroxest. After 20 days, tumor samples were taken for histopathological study and for determination of the expression of the prognostic markers Ki67 and vascular endothelial growth factor (VEGF) by immunofluorescence. RESULTS: In sections stained with hematoxylin-eosin, we observed that tumors have a well-defined capsule enclosing E0771 tumor cells. The central area of tumors contains necrotic regions with leukocyte infiltration. Meroxest treatment significantly reduces tumor size (68%, p < 0.05), induces changes in its structure, decreases the degree of leukocyte infiltration, and significantly reduces the expression of Ki67 (33%, p < 0.05) and VEGF (82%, p < 0.05). CONCLUSIONS: Meroxest improves the prognosis of mice since it reduces leukocyte infiltration, and decreases the expression of Ki67 and VEGF markers. Consequently, the merosesquiterpene could become a useful antiangiogenic drug in the treatment of breast cancer. These results encourage us to deepen the study of meroxest, in order to find more evidence that supports the convenience of its evaluation in a clinical study or trial.

Antioxidant Intake and Antitumor Therapy: Toward Nutritional Recommendations for Optimal Results.

The role of the induction of oxidative stress as the mechanism of action of many antitumor drugs is acquiring an increasing interest. In such cases, the antitumor therapy success may be conditioned by the antioxidants present in our own body, which can be synthesized de novo (endogenous) or incorporated through the diet and nutritional supplements (exogenous). In this paper, we have reviewed different aspects of antioxidants, including their classification, natural sources, importance in diet, consumption of nutritional supplements, and the impact of antioxidants on health. Moreover, we have focused especially on the study of the interaction between antioxidants and antitumor therapy, considering both radiotherapy and chemotherapy. In this regard, we found that the convenience of administration of antioxidants during cancer treatment still remains a very controversial issue. In general terms, antioxidants could promote or suppress the effectiveness of antitumor treatment and even protect healthy tissues against damage induced by oxidative stress. The effects may depend on many factors discussed in the paper. These factors should be taken into consideration in order to achieve precise nutritional recommendations for patients. The evidence at the moment suggests that the supplementation or restriction of exogenous antioxidants during cancer treatment, as appropriate, could contribute to improving its efficiency.

First enantiospecific syntheses of marine merosesquiterpenes neopetrosiquinones a and B: evaluation of biological activity.

The first enantiospecific syntheses of neopetrosiquinones A (6) and B (7), two merosesquiterpenes isolated from the deep-water sponge Neopetrosia cf. proxima, from the labdane diterpene trans-communic acid (10) have been achieved. A key step of the synthetic sequence is the simultaneous aromatization of the C ring and the benzylic oxidation on C-7 of an advanced intermediate, mediated by the oxygen-DDQ system. The in vitro antiproliferative activities of neopetrosiquinone B (7) and of the synthetic intermediates 8 and 9 against human breast (MCF-7), lung (A-549), and colon (T-84) tumor cell lines have been assayed. The most potent was compound 9 (IC50 = 4.1 µM), which was twice as active as natural compound 7 (IC50 = 8.3 µM) against A-549 cells. In addition, the treatment with these compounds resulted in an induction of apoptosis. These findings indicate that the terpene benzoquinones reported here might be potentially useful as anticancer agents.

Computer tools and collaborative translational research in the life sciences: the further advance of genomics and proteomics

Currently, biomedical research is mainly focused on overcoming the major challenges faced by society, including the development of new therapeutic strategies against highly prevalent diseases. Over the past 20 years, considerable advances in this field have been achieved through an interdisciplinary and collaborative approach, enhanced by the development of computer science and its applications in genomics and proteomics. This study centers on platforms for the data management of research assets with high specialization in genomics and proteomics, analyzing the role of web-based databases in the progress made in these areas and evaluating their impact on global scientific production. The web platforms analyzed have proven to be an important resource for stimulating the integration of research data through information exchange. Specialized web search sites facilitate the obtaining of data in these specific areas, creating a trend in current biomedical research. The importance of these platforms is revealed by their impact on scientific production, with some being referenced in more than 100,000 articles and patents. A wider extension of the use of these tools can be expected within the modern society of information

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Cumulative live birth rate after two single frozen embryo transfers (eSFET) versus a double frozen embryo transfer (DFET) with cleavage stage embryos: a retrospective cohort study.

PURPOSE: According to the latest ART report for Europe, about 13% of pregnancies after frozen embryo transfer are multiple. Our objective was to analyse the impact on the multiple pregnancy rate of two eSFET (elective single frozen embryo transfers) versus a DFET (double frozen embryo transfer) in women aged under 38 years, who had not achieved pregnancy in their fresh transfer and who had at least two vitrified embryos of A/B quality. METHODS: This study was conducted from January 2010 to June 2013 at a public hospital. The couples were divided into three groups. Group DFET: the first cryotransfer of two embryos (105 women); cSFET group: the only cryotransfer of a single vitrified embryo (60 women); eSFET group, individually vitrified embryos: 20 patients included in a clinical trial of single-embryo fresh and frozen transfer and 21 patients who chose to receive eSFET. RESULTS: The clinical pregnancy rate was 38.1% in the DET group and the cumulative clinical pregnancy rate was 43.3% in the eSFET group. There were no significant differences between the DFET and eSFET groups (30.0 vs 34.1%) in cumulative live birth delivery rate. The rate of multiple pregnancies varied significantly between the DFET and eSFET groups (32.5 vs 0%, p < 0.05). CONCLUSIONS: For good-prognosis women aged under 38 years, taking embryo quality as a criterion for inclusion, an eSFET policy can be applied, achieving acceptable cumulative clinical pregnancy and live birth rates and reducing multiple pregnancy rates.