973 resultados para BREAST-MILK


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Tenascins are extracellular matrix proteins present during the development of organisms as well as in pathological conditions. Tenascin-W, the fourth and last member of the tenascin family remains the least well-characterized one. Our study aimed to evaluate the potential significance of tenascin-W as cancer biomarker by monitoring its presence in the serum of colorectal and breast cancer patients and its expression in colorectal tumor tissues. To measure serum tenascin-W levels, a sensitive sandwich-ELISA was established. Mean tenascin-W concentration in sera of patients with nonmetastatic colorectal cancer at time of diagnosis was highly increased compared to that of healthy volunteers. A similar tendency was observed for tenascin-C in the same patient cohort. However, the increase was much more striking for tenascin-W. We also detected elevated tenascin-W levels in sera of breast cancer patients. Furthermore, we could show a prominent expression of tenascin-W in extracts from colorectal tumor tissues by immunoblot analysis, whereas tenascin-W was not detectable in the corresponding normal colon mucosa. To confirm the western blot results, we performed immunohistochemistry of frozen sections of the same patients as well as of an additional, independently chosen collection of colorectal cancer tissues. In all cases, similarly to tenascin-C, tenascin-W was detected in the tumor stroma. Our results reveal a clear association between elevated levels of tenascin-W and the presence of cancer. These results warrant further studies to evaluate the potential value of serum and tissue tenascin-W levels as diagnostic, prognostic or monitoring biomarker in colorectal, breast and possibly other solid cancers.

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Anti-angiogenic therapies have recently enriched the therapeutic armentarium against the most common cancers. Among these, bevacizumab, a monoclonal antibody against vascular endothelial growth factor, is currently used most frequently. While the addition of bevacizumab to chemotherapy improves overall survival in first and second line treatment of metastatic colorectal cancer, its effect in metastatic breast cancer is limited to improvements in tumor response and progression-free-survival. In non-small-cell lung cancer, the positive results of a first American phase III study have not been confirmed by a second European study and are subject to controversies. A summary of the data concerning anti-angiogenic therapies in these three cancers is presented including safety information.

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The objective of this study was to comprehensively compare the genomic profiles in the breast of parous and nulliparous postmenopausal women to identify genes that permanently change their expression following pregnancy. The study was designed as a two-phase approach. In the discovery phase, we compared breast genomic profiles of 37 parous with 18 nulliparous postmenopausal women. In the validation phase, confirmation of the genomic patterns observed in the discovery phase was sought in an independent set of 30 parous and 22 nulliparous postmenopausal women. RNA was hybridized to Affymetrix HG_U133 Plus 2.0 oligonucleotide arrays containing probes to 54,675 transcripts, scanned and the images analyzed using Affymetrix GCOS software. Surrogate variable analysis, logistic regression, and significance analysis of microarrays were used to identify statistically significant differences in expression of genes. The false discovery rate (FDR) approach was used to control for multiple comparisons. We found that 208 genes (305 probe sets) were differentially expressed between parous and nulliparous women in both discovery and validation phases of the study at an FDR of 10% and with at least a 1.25-fold change. These genes are involved in regulation of transcription, centrosome organization, RNA splicing, cell-cycle control, adhesion, and differentiation. The results provide initial evidence that full-term pregnancy induces long-term genomic changes in the breast. The genomic signature of pregnancy could be used as an intermediate marker to assess potential chemopreventive interventions with hormones mimicking the effects of pregnancy for prevention of breast cancer.

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Selostus: Tankkimaidon juoksettumisominaisuuksien vaikutus Emmental-juuston määrään ja koostumukseen

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Inhaled therapies are preferred to systemic ones during pregnancy and breast feeding. A real paradox exists however between the necessity to ensure an optimal treatment for pregnant women with asthma, in order to prevent fetal hypoxia, and the precaution linked to any drug prescription during pregnancy. Thus, the use of topical corticosteroids remains the first choice for asthma as well as rhinitis. Inhaled beta2-agonists are also recommended. Systemic corticosteroids may however be prescribed without hesitation when their use is required for asthma treatment. It is also interesting to note that oral second-generation antihistamines are currently allowed during pregnancy and breast feeding. This type of antihistamines is indeed to be preferred to first-generation ones that generate more side-effects and generally are thus not to be prescribed during breast feeding.

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Selostus: Eräiden ympäristövirikkeiden saatavuuden estämisen välittömät vaikutukset tarhaminkin käyttäytymiseen

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Summary The cyclin-dependent kinase inhibitor p16(INK4a) (CDKN2A) is an important tumor-suppressor gene frequently inactivated in human tumors. p16 suppresses the development of cancer by triggering an irreversible arrest of cell proliferation termed cellular senescence. Here, we describe another anti-oncogenic function of p16 in addition to its ability to halt cell cycle progression. We show that transient expression of p16 stably represses the hTERT gene, encoding the catalytic subunit of telomerase, in both normal and malignant breast epithelial cells. Short-term p16 expression increases the amount of histone H3 trimethylated on lysine 27 (H3K27) bound to the hTERT promoter, resulting in transcriptional silencing, likely mediated by polycomb complexes. Our results indicate that transient p16 exposure may prevent malignant progression in dividing cells by irreversible repression of genes, such as hTERT, whose activity is necessary for extensive self-renewal.

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INTRODUCTION: Triple-negative breast cancers (TNBCs) are characterised by lack of expression of hormone receptors and epidermal growth factor receptor 2 (HER-2). As they frequently express epidermal growth factor receptors (EGFRs), anti-EGFR therapies are currently assessed for this breast cancer subtype as an alternative to treatments that target HER-2 or hormone receptors. Recently, EGFR-activating mutations have been reported in TNBC specimens in an East Asian population. Because variations in the frequency of EGFR-activating mutations in East Asians and other patients with lung cancer have been described, we evaluated the EGFR mutational profile in tumour samples from European patients with TNBC. METHODS: We selected from a DNA tumour bank 229 DNA samples isolated from frozen, histologically proven and macrodissected invasive TNBC specimens from European patients. PCR and high-resolution melting (HRM) analyses were used to detect mutations in exons 19 and 21 of EGFR. The results were then confirmed by bidirectional sequencing of all samples. RESULTS: HRM analysis allowed the detection of three EGFR exon 21 mutations, but no exon 19 mutations. There was 100% concordance between the HRM and sequencing results. The three patients with EGFR exon 21 abnormal HRM profiles harboured the rare R836R SNP, but no EGFR-activating mutation was identified. CONCLUSIONS: This study highlights variations in the prevalence of EGFR mutations in TNBC. These variations have crucial implications for the design of clinical trials involving anti-EGFR treatments in TNBC and for identifying the potential target population.

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In order for some patients to benefit from aggressive chemotherapy for invasive breast carcinoma, many patients are currently being treated without little or no benefit. Enormous effort is hence being directed towards the identification of those patients who will need chemotherapy and those who will not. Since chemotherapy targets proliferating cells pathologists focus on the proliferative activity of tumors, as assessed by mitotic figure counts or by cell cycle specific immunohistochemical markers, such as Ki-67 and H3 histone. As far as the tumor grade is concerned, many of these studies have reported a tendency to up-grade carcinomas in resection specimen when compared to the initial diagnosis on the biopsy material, and most studies have noted that the upgrade in resection specimen is due solely or to a large extent to an increase in the mitotic figure count. In the present study, we propose a different explanation for the divergence in mitotic figure counts between biopsy and resection material. We assessed the proliferative activity of 52 invasive ductal carcinomas and confirm that the number of mitotic figures significantly increased by a factor of more than 3 in resection specimen over the biopsy material, while at the same time the pan-cell cycle specific marker MIB-1 yieldes comparable results. we propose that the delayed formalin fixation of resection specimen allows cell cycle activities to continue for a long time, up to many hours, and that this leads to an arrest of mitoses in metaphase where they are readily identified by the pathologist. We propose that the mitotic figure count in the rapidly fixed biopsy cores better represent the tumor biology and should be used as a basis for chemotherapy therapeutic decisions.

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PURPOSE: Local breast cancer relapse after breast-saving surgery and radiotherapy is associated with increased risk of distant metastasis formation. The mechanisms involved remain largely elusive. We used the well-characterized 4T1 syngeneic, orthotopic breast cancer model to identify novel mechanisms of postradiation metastasis. EXPERIMENTAL DESIGN: 4T1 cells were injected in 20 Gy preirradiated mammary tissue to mimic postradiation relapses, or in nonirradiated mammary tissue, as control, of immunocompetent BALB/c mice. Molecular, biochemical, cellular, histologic analyses, adoptive cell transfer, genetic, and pharmacologic interventions were carried out. RESULTS: Tumors growing in preirradiated mammary tissue had reduced angiogenesis and were more hypoxic, invasive, and metastatic to lung and lymph nodes compared with control tumors. Increased metastasis involved the mobilization of CD11b(+)c-Kit(+)Ly6G(high)Ly6C(low)(Gr1(+)) myeloid cells through the HIF1-dependent expression of Kit ligand (KitL) by hypoxic tumor cells. KitL-mobilized myeloid cells homed to primary tumors and premetastatic lungs, to give rise to CD11b(+)c-Kit(-) cells. Pharmacologic inhibition of HIF1, silencing of KitL expression in tumor cells, and inhibition of c-Kit with an anti-c-Kit-blocking antibody or with a tyrosine kinase inhibitor prevented the mobilization of CD11b(+)c-Kit(+) cells and attenuated metastasis. C-Kit inhibition was also effective in reducing mobilization of CD11b(+)c-Kit(+) cells and inhibiting lung metastasis after irradiation of established tumors. CONCLUSIONS: Our work defines KitL/c-Kit as a previously unidentified axis critically involved in promoting metastasis of 4T1 tumors growing in preirradiated mammary tissue. Pharmacologic inhibition of this axis represents a potential therapeutic strategy to prevent metastasis in breast cancer patients with local relapses after radiotherapy. Clin Cancer Res; 18(16); 4365-74. ©2012 AACR.

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BACKGROUND: Brain metastases (BMs) pose a clinical challenge in breast cancer (BC). Lapatinib or temozolomide showed activity in BM. Our study assessed the combination of both drugs as treatment for patients with HER2-positive BC and BM. METHODS: Eighteen patients were enrolled, with sixteen of them having recurrent or progressive BM. Any type of previous therapy was allowed, and disease was assessed by gadolinium (Gd)-enhanced magnetic resonance imaging (MRI). The primary end points were the evaluation of the dose-limiting toxicities (DLTs) and the determination of the maximum-tolerated dose (MTD). The secondary end points included objective response rate, clinical benefit and duration of response. RESULTS: The lapatinib-temozolomide regimen showed a favorable toxicity profile because the MTD could not be reached. The most common adverse events (AEs) were fatigue, diarrhea and constipation. Disease stabilization was achieved in 10 out of 15 assessable patients. The estimated median survival time for the 16 patients with BM reached 10.94 months (95% CI: 1.09-20.79), whereas the median progression-free survival time was 2.60 months [95% confidence interval (CI): 1.82-3.37]. CONCLUSIONS: The lapatinib-temozolomide combination is well tolerated. Preliminary evidence of clinical activity was observed in a heavily pretreated population, as indicated by the volumetric reductions occurring in brain lesions.

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BACKGROUND: Pegylated liposomal doxorubicin (PLD) and bevacizumab are active agents in the treatment of metastatic breast cancer (MBC). We carried out a multicenter, single-arm phase II trial to evaluate the toxicity and efficacy of PLD and bevacizumab as first-line treatment in MBC patients. METHODS: Bevacizumab (10 mg/kg) and PLD (20 mg/m(2)) were infused on days 1 and 15 of a 4-week cycle for a maximum of six cycles. Thereafter, bevacizumab monotherapy was continued at the same dose until progression or toxicity. The primary objective was safety and tolerability, and the secondary objective was to evaluate efficacy of the combination. RESULTS: Thirty-nine of 43 patients were assessable for the primary end point. Eighteen of 39 patients (46%, 95% confidence interval 30% to 63%) had a grade 3 toxicity. Sixteen (41%) had grade 3 palmar-plantar erythrodysesthesia, one had grade 3 mucositis, and one severe cardiotoxicity. Secondary end point of overall response rate among 43 assessable patients was 21%. CONCLUSIONS: In this nonrandomized single-arm trial, the combination of bimonthly PLD and bevacizumab in locally recurrent and MBC patients demonstrated higher than anticipated toxicity while exhibiting only modest activity. Based on these results, we would not consider this combination for further investigation in this setting.

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Since the early 1980s high dose chemotherapy with autologous hematopoietic stem cell support was adopted by many oncologists as a potentially curative option for solid tumors, supported by a strong rationale from laboratory studies and apparently convincing results of early phase II studies. As a result, the number and size of randomized trials comparing this approach with conventional chemotherapy initiated (and often abandoned before completion) to prove or disprove its value was largely insufficient. In fact, with the possible exception of breast carcinoma, the benefit of a greater escalation of dose of chemotherapy with stem cell support in solid tumors is still unsettled and many oncologists believe that this approach should cease. In this article, we critically review and comment on the data from studies of high dose chemotherapy so far reported in adult patients with small cell lung cancer, ovarian cancer, germ cell tumors and sarcomas.

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BACKGROUND: Aromatase inhibitors provide superior disease control when compared with tamoxifen as adjuvant therapy for postmenopausal women with endocrine-responsive early breast cancer. PURPOSE: To present the design, history, and analytic challenges of the Breast International Group (BIG) 1-98 trial: an international, multicenter, randomized, double-blind, phase-III study comparing the aromatase inhibitor letrozole with tamoxifen in this clinical setting. METHODS: From 1998-2003, BIG 1-98 enrolled 8028 women to receive monotherapy with either tamoxifen or letrozole for 5 years, or sequential therapy of 2 years of one agent followed by 3 years of the other. Randomization to one of four treatment groups permitted two complementary analyses to be conducted several years apart. The first, reported in 2005, provided a head-to-head comparison of letrozole versus tamoxifen. Statistical power was increased by an enriched design, which included patients who were assigned sequential treatments until the time of the treatment switch. The second, reported in late 2008, used a conditional landmark approach to test the hypothesis that switching endocrine agents at approximately 2 years from randomization for patients who are disease-free is superior to continuing with the original agent. RESULTS: The 2005 analysis showed the superiority of letrozole compared with tamoxifen. The patients who were assigned tamoxifen alone were unblinded and offered the opportunity to switch to letrozole. Results from other trials increased the clinical relevance about whether or not to start treatment with letrozole or tamoxifen, and analysis plans were expanded to evaluate sequential versus single-agent strategies from randomization. LIMITATIONS: Due to the unblinding of patients assigned tamoxifen alone, analysis of updated data will require ascertainment of the influence of selective crossover from tamoxifen to letrozole. CONCLUSIONS: BIG 1-98 is an example of an enriched design, involving complementary analyses addressing different questions several years apart, and subject to evolving analytic plans influenced by new data that emerge over time.