Low thrombin generation in postmenopausal women using estetrol.

OBJECTIVE: Estetrol (E4) represents a novel estrogen of interest to relieve vasomotor symptoms. E4 activates the nuclear estrogen receptor α (ERα) but antagonizes the estradiol ERα-dependent membrane-initiated steroid signaling pathway. The distinct pharmacological properties of E4 could explain its low impact on hemostasis. This study aimed to assess the effect of E4 on coagulation in postmenopausal women, using the thrombin generation assay (TGA). METHODS: Data were collected from a multicenter, randomized, placebo-controlled, dose-finding study in postmenopausal women (NCT02834312). Oral E4 (2.5 mg, n = 42; 5 mg, n = 29; 10 mg, n = 34; or 15 mg, n = 32) or placebo (n = 31) was administered daily for 12 weeks. Thrombograms and TGA parameters were extracted for each subject at baseline and after 12 weeks of treatment. RESULTS: After 12 weeks of treatment, all treatment groups showed a mean thrombogram (±95% confidence interval [CI] of the mean) within the reference ranges, that is, the 2.5th-97.5th percentile of all baseline thrombograms (n = 168), as well as for TGA parameters. CONCLUSIONS: The intake of E4 15 mg for 12 weeks led to significant but not clinically relevant changes compared to baseline as the mean values (±95% CI of the mean) remained within reference ranges, demonstrating a neutral profile of this estrogen on hemostasis.

Impact of estetrol (E4) on hemostasis, metabolism and bone turnover in postmenopausal women.

OBJECTIVE: This study aimed to determine the effects of estetrol (E4) on hemostasis, lipids, carbohydrate metabolism and bone turnover in postmenopausal women. METHODS: This study was a multicenter, randomized, double-blind placebo-controlled phase 2 trial. Participants (n = 180, age 43-64 years) received E4 2.5 mg, 5 mg, 10 mg and 15 mg or placebo once daily for 12 weeks. Changes from baseline at week 12 were evaluated versus placebo for hemostasis parameters, sex hormone binding globulin (SHBG), lipids, carbohydrate metabolism and bone markers. RESULTS: Changes for hemostasis parameters were minimal with a small increase only in the normalized activated protein C sensitivity ratio in the E4 15 mg group versus placebo. SHBG increased in the E4 5 mg, 10 mg and 15 mg groups versus placebo. High-density lipoprotein cholesterol increased in all E4 groups; changes were not consistent for other lipids. Significant decreases versus placebo were seen for insulin resistance (E4 10 mg group), hemoglobin A1c (E4 15 mg group) and type 1 collagen C-terminal telopeptide (E4 10 mg and 15 mg groups). Small decreases in osteocalcin in the E4 5 mg, 10 mg and 15 mg groups were significant versus the increase observed in placebo. CONCLUSION: E4 had limited impact on hemostasis and potentially beneficial effects on lipids, carbohydrate metabolism and bone turnover.

Estetrol-Drospirenone combination oral contraceptive: a clinical study of contraceptive efficacy, bleeding pattern and safety in Europe and Russia.

OBJECTIVES: To assess the contraceptive efficacy, bleeding pattern and safety of a combined oral contraceptive containing estetrol (E4) 15 mg and drospirenone (DRSP) 3 mg. DESIGN: Multicenter, open-label, phase 3 trial. SETTING: Sixty-nine sites in Europe and Russia. POPULATION: Sexually active women aged 18-50 years with regular menstrual cycles and body mass index ≤35 kg/m2 . METHODS: E4/DRSP was administered in a 24 active/4 placebo regimen for up to 13 cycles. Visits were scheduled during Cycles 2, 4, 7 and 10 and after completing treatment during which adverse events (AEs) were collected. Participants recorded medication intake, vaginal bleeding/spotting, use of other contraceptive methods and sexual intercourse on a daily diary. MAIN OUTCOME MEASURES: Pearl Index (PI) for women 18-35 years (overall and method-failure), bleeding pattern and AEs. RESULTS: A total of 1553 women aged 18-50 years, including 1353 from 18 to 35 years old, received the study medication. PI was 0.47 pregnancies/100 woman-years (95% CI 0.15-1.11); method failure PI was 0.29 pregnancies/100 woman-years (95% CI 0.06-0.83). Scheduled bleeding/spotting occurred in 91.9-94.4% of women over Cycles 1 to 12 and lasted a median of 4-5 days per cycle. The percentage of women with unscheduled bleeding/spotting episodes decreased from 23.5% in Cycle 1 to <16% from Cycle 6 onwards. The most common AEs were headache (7.7%), metrorrhagia (5.5%), vaginal haemorrhage (4.8%) and acne (4.2%). One treatment-related serious AE was reported, a lower extremity venous thromboembolism. One-hundred and forty-one (9.1%) women discontinued study participation because of treatment-related adverse events. CONCLUSION: E4/DRSP provides effective contraception, a predictable bleeding pattern and a favourable safety profile. TWEETABLE ABSTRACT: A phase 3 trial with E4/DRSP shows high contraceptive efficacy, a predictable bleeding pattern and favourable safety profile.

Clinical performance of a specific granulocyte colony stimulating factor ELISA to determine its concentration in follicular fluid as a predictor of implantation success during in vitro fertilization.

This study aimed to demonstrate the clinical performance of an ultra-sensitive follicular fluid (FF) granulocyte colony stimulating factor (G-CSF) immunoassay to confirm previous work, indicating a correlation between FF G-CSF concentration and live birth potential of the corresponding embryo after in vitro fertilization. This study was a noninterventional, prospective, diagnostic clinical multicentric study conducted between August 2012 and January 2014 with 396 single embryo transfers (SETs) from 278 subjects. During oocyte retrieval, FF was individually collected. Embryo morphology and implantation success were evaluated. The implantation success rate in the high G-CSF group (32.3%) was higher than the overall rate (27.5%). Similarly, for embryos with optimal morphology, implantation success rates were highest among those in the high G-CSF concentration category (34.5%) compared with low (19.6%) and intermediate (29.8%) G-CSF concentration categories. Significant differences in mean G-CSF concentrations were observed between the study sites. To minimize bias, analyses were repeated using data from the center with the largest number of SETs. In alignment with the overall analysis, this center demonstrated a 43% greater probability of implantation for optimal embryos with high G-CSF compared to the general implantation rate among optimal embryos and a 327% increase compared with the implantation rate of optimal embryos with low G-CSF.

Pharmacokinetics of the fetal estrogen estetrol in a multiple-rising-dose study in postmenopausal women.

OBJECTIVES: Estetrol (E4) is a natural fetal estrogen. In this open-label, multiple-rising-dose study, the pharmacokinetic effects of E4 in postmenopausal women were investigated as a secondary objective. METHODS: In total, 49 postmenopausal women were randomized to receive either 2 mg E4 or 2 mg estradiol valerate (E2V) for 28 days, or were (non-randomized) assigned to 10, 20, or 40 mg E4. The main outcome measures were: E4 plasma concentrations at trough, and on days 1 and 28; and E4 pharmacokinetic parameters AUC, Cmax and tmax on days 1 and 28. RESULTS: After oral administration, E4 showed a very fast absorption, followed by a multiphasic elimination with an initial rapid decline, gradually continuing with a slower elimination, suggesting a long terminal half-life. Steady state was reached within 2 weeks of dosing and pharmacokinetic results were generally proportional to the dose. Estetrol concentrations on day 28 were slightly higher compared to day 1, indicating some accumulation. CONCLUSION: The pharmacokinetic profile of estetrol is characterized by a very fast absorption phase, followed by an initial rapid decline, and a slow terminal elimination phase. Based on its kinetic properties, estetrol seems suitable for use as a once-daily oral drug.

Influence de la co-infection paludéenne placentaire et VIH sur la biométrie et l'indice d'Apgar du nouveau - né à Kinshasa, République Démocratique du Congo

Introduction: La co-infection VIH-paludisme est très fréquente dans les régions d'endémie palustre et de haute prévalence du VIH/SIDA. Dans les régions de paludisme stable, l'infection par le VIH augmente les risques de paludisme asymptomatique, d'accès palustre simple et de létalité liée à cette parasitose. Evaluer l'impact de la co-infection VIH et l'infection paludéenne placentaire sur les paramètres biométriques et l'indice d'Apgar du nouveau-né sont les objectifs de ce travail. Matériel et Méthodes: Nous avons conduit une étude transversale comparative. 146 VIH+ et 149 VIH-mères consentantes et leurs nouveau-nés ont été recrutés dans 7 Maternités de Kinshasa (RDC). Les biopsies placentaires examinées au Service d'anatomopathologie de l'Université de Kinshasa confirment la présence de trophozoïtes. Les tests Chi carré, exact de Fisher et le t-Student ont servi aux analyses statistiques des données Résultats: La prévalence de l'infection paludéenne placentaire était de 72%. Cette infestation était plus importante dans le groupe des mères VIH+ avec 91% vs 53,70% pour les mères VIH-(p<0,0001).La moyenne de poids de naissance (PN) des nouveau-nés nés des mères co-infectées était inférieure à celle des enfants nés de mères VIH-avec placentas infectés (3033 ±524 g vs 3236 ±565g, p=0,009). Les nouveau-nés dont l'Apgar à la 5ième minute était <7 sont tous nés de mères co-infectées (p=0,009). Conclusion: La co-infection VIH et paludisme placentaire des gestantes influence négativement le PN et l'Apgar à la 5ième minute des nouveau-nés

Restoring testosterone levels by adding dehydroepiandrosterone to a drospirenone containing combined oral contraceptive: I. Endocrine effects.

OBJECTIVES: Combined oral contraceptives (COCs) decrease testosterone (T) levels. This study investigated restoration of T and other androgen concentrations during COC use by 'co-administration' of dehydroepiandrosterone (DHEA). STUDY DESIGN: In this randomized, double-blind, placebo-controlled study in 99 new COC starters (18-35 years old with body mass index range 18-34 kg/m²), a COC containing 30mcg ethinylestradiol (EE) and 3 mg drospirenone (DRSP) was used for 3cycles, followed by 6cycles of the same COC combined with either 50 mg/day DHEA or placebo. Total T, albumin, sex hormone-binding globulin (SHBG), DHEA-sulfate (DHEA-S), Δ4-androstenedione (AD), 3α-androstanediol glucuronide (ADG) and estradiol (E2) were measured, whereas free T and the free T index (FTI) were calculated. Assessments took place at baseline (no COC use), after the run-in period (COC use alone) and during the treatment period (DHEA or placebo). RESULTS: During COC use alone, androgen levels decreased, especially total T by 62% and free T by 86%, and SHBG increased by 243%. Total T increased with DHEA compared to placebo (change from end of run-in period to end of treatment period -- 1.3±1.2 nmol/L vs. 0.0±0.4 nmol/L; p<.0001) -- and was restored to baseline levels. Free T and the FTI increased significantly (p<.0001), but the free T level was still 53% below baseline levels. DHEA-S, AD and ADG increased significantly to levels above baseline (p<.0001 for each). DHEA had no effect on SHBG, albumin and E2. CONCLUSIONS: An EE/DRSP containing COC strongly suppressed endogenous androgen concentrations in all users. The addition of 50 mg DHEA to a COC regimen containing EE/DRSP restored total T to baseline levels, but free T levels were restored by only 47% as most of the T remains bound to SHBG. IMPLICATIONS: When using a COC that increases SHBG considerably, a daily dose of 50 mg DHEA is insufficient to normalize free T levels completely.

Estetrol is a weak estrogen antagonizing estradiol-dependent mammary gland proliferation.

Estetrol (E4) is a natural estrogen produced exclusively by the human fetal liver during pregnancy. Its physiological activity remains unknown. In contrast to ethinyl estradiol and estradiol (E2), E4 has a minimal impact on liver cell activity and could provide a better safety profile in contraception or hormone therapy. The aim of this study was to delineate if E4 exhibits an activity profile distinct from that of E2 on mammary gland. Compared with E2, E4 acted as a low-affinity estrogen in both human in vitro and murine in vivo models. E4 was 100 times less potent than E2 to stimulate the proliferation of human breast epithelial (HBE) cells and murine mammary gland in vitro and in vivo respectively. This effect was prevented by fulvestrant and tamoxifen, supporting the notion that ERα (ESR1) is the main mediator of the estrogenic effect of E4 on the breast. Interestingly, when E4 was administered along with E2, it significantly antagonized the strong stimulatory effect of E2 on HBE cell proliferation and on the growth of mammary ducts. This study characterizes for the first time the impact of E4 on mammary gland. Our results highlight that E4 is less potent than E2 and exhibits antagonistic properties toward the proliferative effect of E2 on breast epithelial cells. These data support E4 as a potential new estrogen for clinical use with a reduced impact on breast proliferation.

Restoring testosterone levels by adding dehydroepiandrosterone to a drospirenone containing combined oral contraceptive: II. Clinical effects.

OBJECTIVES: Combined oral contraceptives (COCs) decrease androgen levels, including testosterone (T), which may be associated with sexual dysfunction and mood complaints in some women. We have shown that 'co-administration' of dehydroepiandrosterone (DHEA) to a drospirenone (DRSP)-containing COC restored total T levels to baseline and free T levels by 47%. Here we describe the effects on sexual function, mood and quality of life of such an intervention. STUDY DESIGN: This was a randomized, double-blind, placebo-controlled study in 99 healthy COC starters. A COC containing 30 mcg ethinylestradiol (EE) and 3 mg DRSP was used for three cycles, followed by six cycles of the same COC combined with 50 mg/day DHEA or placebo. Subjects completed the Moos Menstrual Distress Questionnaire (MDQ), the McCoy Female Sexuality Questionnaire and the short form of the Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q). Safety and tolerability, including effects on skin, were evaluated. RESULTS: The addition of DHEA induced small but significant improvements compared to placebo in the MDQ score for autonomic reactions during the menstrual (-2.0 vs. 0.71; p=0.05) and the premenstrual phase (-3.1 vs. 2.9; p=0.01) and for behavior during the intermenstrual phase (-1.4 vs. 3.6; p=0.02). A significant difference was found in the MDQ score for arousal during the premenstrual phase in favor of placebo (-5.0 vs. 1.0; p=0.01). There were no statistically significant differences between groups for the MSFQ and Q-LES-Q scores. DHEA 'co-administration' resulted in an acceptable safety profile. DHEA negated the beneficial effect of the COC on acne according to the subjects' self-assessment. CONCLUSIONS: 'Co-administration' with DHEA did not result in consistent improvements in sexual function, mood and quality of life indicators in women taking EE/DRSP. Retrospectively, the 50 mg dose of DHEA may be too low for this COC. IMPLICATIONS: A well-balanced judgment of the clinical consequences of normalizing androgens during COC use may require complete normalization of free T.

Impact of follicular G-CSF quantification on subsequent embryo transfer decisions: a proof of concept study.

BACKGROUND: Previous experiments have shown that granulocyte colony-stimulating factor (G-CSF), quantified in the follicular fluid (FF) of individual oocytes, correlates with the potential for an ongoing pregnancy of the corresponding fertilized oocytes among selected transferred embryos. Here we present a proof of concept study aimed at evaluating the impact of including FF G-CSF quantification in the embryo transfer decisions. METHODS: FF G-CSF was quantified with the Luminex XMap technology in 523 individual FF samples corresponding to 116 fresh transferred embryos, 275 frozen embryos and 131 destroyed embryos from 78 patients undergoing ICSI. RESULTS: Follicular G-CSF was highly predictive of subsequent implantation. The receiving operator characteristics curve methodology showed its higher discriminatory power to predict ongoing pregnancy in multivariate logistic regression analysis for FF G-CSF compared with embryo morphology [0.77 (0.69-0.83), P < 0.001 versus 0.66 (0.58-0.73), P = 0.01)]. Embryos were classified by their FF G-CSF concentration: Class I over 30 pg/ml (a highest positive predictive value for implantation), Class II from 30 to 18.4 pg/ml and Class III <18.4 pg/ml (a highest negative predictive value). Embryos derived from Class I follicles had a significantly higher implantation rate (IR) than those from Class II and III follicles (36 versus 16.6 and 6%, P < 0.001). Embryos derived from Class I follicles with an optimal morphology reached an IR of 54%. Frozen-thawed embryos transfer derived from Class I follicles had an IR of 37% significantly higher than those from Class II and III follicles, respectively, of 8 and 5% (P < 0.001). Thirty-five per cent of the frozen embryos but also 10% of the destroyed embryos were derived from G-CSF Class I follicles. Non-optimal embryos appear to have been transferred in 28% (22/78) of the women, and their pregnancy rate was significantly lower than that of women who received at least one optimal embryo (18 versus 36%, P = 0.04). CONCLUSIONS: Monitoring FF G-CSF for the selection of embryos with a better potential for pregnancy might improve the effectiveness of IVF by reducing the time and cost required for obtaining a pregnancy.

[Premature ovarian failure, from genetics to clinical]. / Insuffisance ovarienne prématurée: de la génétique à la clinique.

Premature Ovarian Failure (POF) is a condition with complicated clinical presentation. An estimated 1% of the population is affected before the age of 40, with 0.1% affected prior to the age of 30. There are many causes of POI: genetic aberrations, auto-immune ovarian damage, iatrogenic factors following surgery, radiotherapy or chemotherapy, environmental factors (viruses, toxins, smoking) and metabolic. The majority of POF cases have idiopathic etiologies.

Curcumin-cyclodextrin complexes potentiate gemcitabine effects in an orthotopic mouse model of lung cancer.

BACKGROUND: Overall clinical outcome for advanced lung cancer remains very disappointing despite recent advances in treatment. Curcumin has been reported as potentially active against cancer. METHODS: Owing to poor curcumin solubility, we have used cyclodextrins (CD) as an excipient allowing a considerable increase of aqueous solubility and bioavailability of curcumin. The effects of solubilised curcumin have been evaluated in cell cultures as well as in an in vivo orthotopic lung tumour mouse model. RESULTS: Cell proliferation was reduced while apoptosis rates were increased when lung epithelial tumour cells were cultured in the presence of curcumin-CD complexes. For in vivo experiments, cells were grafted into lungs of C57Bl/6 mice treated by an oral administration of a non-soluble form of curcumin, CDs alone or curcumin-CD complexes, combined or not with gemcitabine. The size of orthotopically implanted lung tumours was reduced upon curcumin complex administration as compared with treatments with placebo or non-solubilised curcumin. Moreover, curcumin potentiated the gemcitabine-mediated antitumour effects. CONCLUSION: Our data demonstrate that curcumin, when given orally in a CD-solubilised form, reduces lung tumour size in vivo. In vitro experiments show impaired tumour cell proliferation and increased cell apoptosis. Moreover, our data underline a potential additive effect of curcumin with gemcitabine thus providing an efficient therapeutic option for antilung cancer therapy.

Adverse obstetrical outcomes after treatment of precancerous cervical lesions: a Belgian multicentre study.

OBJECTIVE: To assess the impact of cervical intraepithelial neoplasia (CIN) treatment on the risk of (spontaneous) preterm delivery (PD) and small for gestational age (SGA) at birth. DESIGN: A multicentre cohort study. SETTING: Maternity wards of four academic hospitals in Belgium. POPULATION: Ninety-seven exposed pregnant women (with a CIN treatment history) and 194 nonexposed pregnant women (without a history of CIN treatment). METHODS: A questionnaire and check of obstetrical files included socio-demographic characteristics, risk factors for PD, obstetrical history for all women and characteristics of the CIN treatment for exposed women. Pregnancy outcomes were recorded after delivery. The influence of previous treatment of CIN on pregnancy outcomes, adjusted for confounding variables, was assessed by Cox regression and lifetables (for the outcome gestational age at birth) and by logistic regression (for the outcomes PD and SGA at birth). MAIN OUTCOME MEASURES: Occurrence of PD and SGA at birth. RESULTS: Seventy-nine per cent of the women in the database were multiparous; 16.3% of women with a previous excisional treatment spontaneously delivered preterm, compared with 8.1% of unexposed women [odds ratio (OR), 2.19; 95% confidence interval (CI), 0.97-4.99]. When adjusting for confounding factors (ethnicity, HIV status, education, age, smoking and parity), the OR for PD was 2.33 (95% CI, 0.99-5.49). Excisional treatment did not have an impact on SGA at birth (OR, 0.94; 95% CI,0.41-2.15). The depth of the cone was >10 mm in 63.5% of the documented cases. Large cones, more than 10 mm deep, were associated with a significantly increased risk of PD (adjusted OR, 4.55; 95% CI, 1.32-15.65) compared with untreated women, whereas smaller cones (≤ 10 mm) were not significantly associated with PD (OR, 2.77; 95% CI, 0.28-27.59). The associations seen for PD with respect to the cone size did not hold for SGA at birth. CONCLUSIONS: There was an increased risk of (spontaneous) PD after excision of CIN, in particular when the cone depth exceeded 10 mm.

[Obstetrical epidural analgesia and postpartum backache]. / Analgésie péridurale obstétricale et lombalgie du post-partum: un lien de cause a effet?

Backache is a common problem in the general population. The prevalence of backpain is increased during pregnancy and after delivery. Early studies have suggested that labor epidural analgesia might be associated with an increased incidence of backache in the postpartum period. However, these initial studies were retrospective and their design included several methodological deficiencies. All the prospective studies published afterwards (prospective cohort studies and 3 randomized controlled trials) yield the same result: there is no relationship between labor epidural analgesia and long-term postpartum backpain. Pregnant women must be aware of this in order to make an informed and appropriate choice about labor epidural analgesia, the most effective technique for intrapartum pain relief.

MT1-MMP protects breast carcinoma cells against type I collagen-induced apoptosis.

As invading breast carcinoma cells breach their underlying basement membrane, they become confronted with a dense three-dimensional reactive stroma dominated by type I collagen. To develop metastatic capabilities, invading tumor cells must acquire the capacity to negotiate this novel microenvironment. Collagen influences the fate of epithelial cells by inducing apoptosis. However, the mechanisms used by invading tumor cells to evade collagen-induced apoptosis remain to be defined. We demonstrate that membrane type-1 matrix metalloproteinase (MT1-MMP/MMP-14) confers breast cancer cells with the ability to escape apoptosis when embedded in a collagen gel and after orthotopic implantation in vivo. In the absence of MMP-14-dependent proteolysis, type I collagen triggers apoptosis by inducing the expression of the pro-apoptotic Bcl-2-interacting killer in luminal-like breast cancer cells. These findings reveal a new mechanism whereby MMP-14 activity promotes tumor progression by circumventing apoptosis.

[Herpes hepatic failure during the third quarter of pregnancy]. / Le cas clinique du mois. Hépatite herpétique au 3eme trimestre de la grossesse.

Acute liver diseases of pregnancy are common and usually transient and reversible. Given the number of different possible diagnoses, performing a large biological screening and a proper iconographic documentation is key. It makes sure no etiology fatal to the mother and her fetus is missed.

A dynamic in vivo model of epithelial-to-mesenchymal transitions in circulating tumor cells and metastases of breast cancer.

Epithelial-to-mesenchymal transition (EMT) processes endow epithelial cells with enhanced migratory/invasive properties and are therefore likely to contribute to tumor invasion and metastatic spread. Because of the difficulty in following EMT processes in human tumors, we have developed and characterized an animal model with transplantable human breast tumor cells (MDA-MB-468) uniquely showing spontaneous EMT events to occur. Using vimentin as a marker of EMT, heterogeneity was revealed in the primary MDA-MB-468 xenografts with vimentin-negative and vimentin-positive areas, as also observed on clinical human invasive breast tumor specimens. Reverse transcriptase-PCR after microdissection of these populations from the xenografts revealed EMT traits in the vimentin-positive zones characterized by enhanced 'mesenchymal gene' expression (Snail, Slug and fibroblast-specific protein-1) and diminished expression of epithelial molecules (E-cadherin, ZO-3 and JAM-A). Circulating tumor cells (CTCs) were detected in the blood as soon as 8 days after s.c. injection, and lung metastases developed in all animals injected as examined by in vivo imaging analyses and histology. High levels of vimentin RNA were detected in CTCs by reverse transcriptase-quantitative PCR as well as, to a lesser extent, Snail and Slug RNA. Von Willebrand Factor/vimentin double immunostainings further showed that tumor cells in vascular tumoral emboli all expressed vimentin. Tumoral emboli in the lungs also expressed vimentin whereas macrometastases displayed heterogenous vimentin expression, as seen in the primary xenografts. In conclusion, our data uniquely demonstrate in an in vivo context that EMT occurs in the primary tumors, and associates with an enhanced ability to intravasate and generate CTCs. They further suggest that mesenchymal-to-epithelial phenomena occur in secondary organs, facilitating the metastatic growth.

[Clinical case of the month. Unfavourable outcome of a triplet gestation]. / Issue d favorable d'une grossesse triple.

Body stalk anomaly is rarely described in triplet gestation after medically assisted procreation. The relationship between congenital anomaly, multiple pregnancy, and medically assisted procreation is briefly discussed.

[Circulating tumor cells: detection, characterization and clinical impact]. / Cellules tumorales circulantes: détection, caractérisation et intérêts cliniques.

The metastatic process generates circulating tumor cells (CTCs) and disseminated tumor cells (DTCs) in bone marrow and other organs which can remain as occult metastases. Various methods and systems have been developed to allow the isolation and identification of those cells but major technical limitations still exist. Research on CTCs is a nevertheless tremendously growing field of cancer research because of their potential clinical applications. CTCs indeed convey predictive information for the development of metastasis and recurrence, and prognostic information regarding patient survival. CTCs enumeration could also be used to monitor the effectiveness of adjuvant treatments. Moreover, enhancing our basic understanding of the metastatic process, CTCs, and DTCs in particular, are thought to contain subpopulations of cells with stem cells properties that would be responsible for relapses.

[Invasion and metastatic dissemination in breast cancer: mechanisms]. / Invasion et dissémination métastatiques dans le cancer du sein: mécanismes.

Metastases formation is a complex process involving genetic and epigenetic modifications leading to several molecular pathway dysfunctions and alterations in the production and fonction of a panel of molecular mediators. Recent studies have shed light on the importance of multiple interactions occuring between tumor cells and host cells involved in the elaboration of a microenvironment permissive for tumor cell survival and growth. These tumor-host interactions are decisive, not only in the primary tumor, but also in secondary sites colonized by tumor cells. Cancer appears more and more as a sytemic disease in which tumor cell is one of the pawn in the game. System of defense are rapidly overwhelmed and tumor cells hijack host cells to promote their dissemination that likely occurs at earlier stages than initially anticipated. In the present review, we describe the novel concepts of metastases formation based on recent transcriptomic analyses and new insights acquired on the tumor microenvironment in the primary tumor and in secondary foci.