656 resultados para Cancer - Aspectos biológicos


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Angiogenesis, the formation of new blood vessels from existing vasculature, is essential to the late stages of carcinogenesis, allowing tumours to grow beyond 1-2 mm in diameter, invade surrounding tissue, and metastasise. However, more than two decades ago, angiogenesis that preceded neoplastic transformation was seen. Indeed, it can be detected in inflammatory and infectious diseases that increase the risk of developing cancer. Recent advances in fluorescence endoscopy and histological assessment suggest that, for certain cancers, the degree of new blood-vessel formation may differ between the early and late stages of carcinogenic progression. The association between angiogenesis and cancer occurrence, and ease of detection of this process in accessible tissues early in carcinogenesis, mean that angiogenesis fulfils the criteria for a biomarker of the effectiveness of chemopreventive intervention. There is also some evidence that biochemical assays of angiogenic growth factors may after similar potential as surrogate biomarkers. Many natural and synthetic chemopreventive agents in development or in clinical use inhibit new vessel formation in vivo. Validation of angiogenesis as a biomarker for the effectiveness of chemoprevention should further the advancement of some chemopreventive agents.

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BACKGROUND: In single-group studies, chromosomal rearrangements of the anaplastic lymphoma kinase gene (ALK ) have been associated with marked clinical responses to crizotinib, an oral tyrosine kinase inhibitor targeting ALK. Whether crizotinib is superior to standard chemotherapy with respect to efficacy is unknown. METHODS: We conducted a phase 3, open-label trial comparing crizotinib with chemotherapy in 347 patients with locally advanced or metastatic ALK-positive lung cancer who had received one prior platinum-based regimen. Patients were randomly assigned to receive oral treatment with crizotinib (250 mg) twice daily or intravenous chemotherapy with either pemetrexed (500 mg per square meter of body-surface area) or docetaxel (75 mg per square meter) every 3 weeks. Patients in the chemotherapy group who had disease progression were permitted to cross over to crizotinib as part of a separate study. The primary end point was progression-free survival. RESULTS: The median progression-free survival was 7.7 months in the crizotinib group and 3.0 months in the chemotherapy group (hazard ratio for progression or death with crizotinib, 0.49; 95% confidence interval [CI], 0.37 to 0.64; P<0.001). The response rates were 65% (95% CI, 58 to 72) with crizotinib, as compared with 20% (95% CI, 14 to 26) with chemotherapy (P<0.001). An interim analysis of overall survival showed no significant improvement with crizotinib as compared with chemotherapy (hazard ratio for death in the crizotinib group, 1.02; 95% CI, 0.68 to 1.54; P=0.54). Common adverse events associated with crizotinib were visual disorder, gastrointestinal side effects, and elevated liver aminotransferase levels, whereas common adverse events with chemotherapy were fatigue, alopecia, and dyspnea. Patients reported greater reductions in symptoms of lung cancer and greater improvement in global quality of life with crizotinib than with chemotherapy. CONCLUSIONS: Crizotinib is superior to standard chemotherapy in patients with previously treated, advanced non-small-cell lung cancer with ALK rearrangement. (Funded by Pfizer; ClinicalTrials.gov number, NCT00932893.) Copyright © 2013 Massachusetts Medical Society.

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Aims: Carbonic anhydrase IX (CA IX) expression has been described as an endogenous marker of hypoxia in solid neoplasms. Furthermore, CA IX expression has been associated with an aggressive phenotype and resistance to radiotherapy. We assessed the prognostic significance of CA IX expression in patients with muscle-invasive bladder cancer treated with radiotherapy. Materials and methods: A standard immunohistochemistry technique was used to show CA IX expression in 110 muscle-invasive bladder tumours treated with radiotherapy. Clinicopathological data were obtained from medical case notes. Results: CA IX immunostaining was detected in 89 (∼81%) patients. Staining was predominantly membranous, with areas of concurrent cytoplasmic and nuclear staining and was abundant in luminal and perinecrotic areas. No significant correlation was shown between the overall CA IX status and the initial response to radiotherapy, 5-year bladder cancer-specific survival or the time to local recurrence. Conclusions: The distribution of CA IX expression in paraffin-embedded tissue sections seen in this series is consistent with previous studies in bladder cancer, but does not provide significant prognostic information with respect to the response to radiotherapy at 3 months and disease-specific survival after radical radiotherapy. © 2007 The Royal College of Radiologists.

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We present the treatment rationale and study design of the MetLung phase III study. This study will investigate onartuzumab (MetMAb) in combination with erlotinib compared with erlotinib alone, as second- or third-line treatment, in patients with advanced non-small-cell lung cancer (NSCLC) who are Met-positive by immunohistochemistry. Approximately 490 patients (245 per treatment arm) will receive erlotinib (150 mg oral daily) plus onartuzumab or placebo (15 mg/kg intravenous every 3 weeks) until disease progression, unacceptable toxicity, patient or physician decision to discontinue, or death. The efficacy objectives of this study are to compare overall survival (OS) (primary endpoint), progression-free survival, and response rates between the 2 treatment arms. In addition, safety, quality of life, pharmacokinetics, and translational research will be investigated across treatment arms. If the primary objective (OS) is achieved, this study will provide robust results toward an alternative treatment option for patients with Met-positive second- or third-line NSCLC. © 2012 Elsevier Inc. All Rights Reserved.

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Metastatic breast cancer (MBC) may present de novo but more commonly develops in women initially presenting with early breast cancer despite the widespread use of adjuvant hormonal and cytotoxic chemotherapy. MBC is incurable. Hormone sensitive MBC eventually becomes resistant to endocrine therapy in most women. Anthracyclines are the agents of choice in the treatment of endocrine resistant MBC. With the widespread use of anthracyclines in the adjuvant setting, taxanes have become the agents of choice for many patients. Recently capecitabine has become established as a standard of care for patients pretreated with anthracyclines and taxanes. However, a range of agents have activity as third line treatment. These include gemcitabine, vinorelbine and platinum analogues. The sequential use of non-cross resistant single agents rather than combination therapy is preferable in most women with MBC. Even though combination therapy can improve response rates and increase progression free interval, there is no robust evidence to indicate an advantage in terms of overall survival. Moreover, combination therapy is associated with a higher toxicity rate and poor quality of life. There is no role for dose-intense therapy, high dose therapy or maintenance chemotherapy outside the context of a clinical trial. The introduction of trastuzumab, monoclonal antibody targeting growth factor receptors, has improved the therapeutic options for women with tumours overexpressing HER2/neu. DNA micro-array profiles of tumours can potentially help to individualise therapy in future. Molecular targeted therapy has the potential to revolutionise the management of MBC.

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The epidermal growth factor receptor (EGFR) is commonly expressed in non-small-cell lung cancer (NSCLC) and promotes a host of mechanisms involved in tumorigenesis. However, EGFR expression does not reliably predict prognosis or response to EGFR-targeted therapies. The data from two previous studies of a series of 181 consecutive surgically resected stage I-IIIA NSCLC patients who had survived in excess of 60 days were explored. Of these patients, tissue was available for evaluation of EGFR in 179 patients, carbonic anhydrase (CA) IX in 177 patients and matrix metalloproteinase-9 (MMP-9) in 169 patients. We have previously reported an association between EGFR expression and MMP-9 expression. We have also reported that MMP-9 (P=0.001) and perinuclear (p)CA IX (P=0.03) but not EGFR expression were associated with a poor prognosis. Perinuclear CA IX expression was also associated with EGFR expression (P<0.001). Multivariate analysis demonstrated that coexpression of MMP-9 with EGFR conferred a worse prognosis than the expression of MMP-9 alone (P<0.001) and coexpression of EGFR and pCA IX conferred a worse prognosis than pCA IX alone (P=0.05). A model was then developed where the study population was divided into three groups: group 1 had expression of EGFR without coexpression of MMP-9 or pCA IX (number=21); group 2 had no expression of EGFR (number=75); and group 3 had coexpression of EGFR with pCA IX or MMP-9 or both (number=70). Group 3 had a worse prognosis than either groups 1 or 2 (P=0.0003 and 0.027, respectively) and group 1 had a better prognosis than group 2 (P=0.036). These data identify two cohorts of EGFR-positive patients with diametrically opposite prognoses. The group expressing either EGFR and or both MMP-9 and pCA IX may identify a group of patients with activated EGFR, which is of clinical relevance with the advent of EGFR-targeted therapies. © 2004 Cancer Research UK.

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Hypoxia-inducible factor (HIF)-1α is the regulatory subunit of HIF-1 that is stabilized under hypoxic conditions. Under different circumstances, HIF-1α may promote both tumorigenesis and apoptosis. There is conflicting data on the importance of HIF-1α as a prognostic factor. This study evaluated HIF-1α expression in 172 consecutive patients with stage I-IIIA non small cell lung cancer (NSCLC) using standard immunohistochemical techniques. The extent of HIF-1α nuclear immunostaining was determined using light microscopy and the results were analyzed using the median (5%) as a low cut-point and 60% as a high positive cut-point. Using the low cut-point, positive associations were found with epidermal growth factor receptor (EGFR; p = 0.01), matrix metalloproteinase (MMP)-9 (p = 0.003), membranous (p < 0.001) and perinuclear (p = 0.004) carbonic anhydrase (CA) IX, pS3 (p = 0.008), T-stage (p = 0.042), tumor necrosis (TN; p < 0.001) and squamous histology (p < 0.001). No significant association was found with Bcl-2 or either N- or overall TMN stage or prognosis. When the high positive cut-point was used, HIF-1α was associated with a poor prognosis (p = 0.034). In conclusion, the associations with EGFR, MMP-9, p53 and CA IX suggest that these factors may either regulate or be regulated by HIF-1α. The association with TN and squamous-type histology, which is relatively more necrotic than other NSCLC types, reflects the role of hypoxia in the regulation of HIF-1α. The prognostic data may reflect a change in the behavior of HIF-1α in increasingly hypoxic environments. © 2004 Wiley-Liss, Inc.

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Background Tumour necrosis (TN) is recognized to be a consequence of chronic cellular hypoxia. TN and hypoxia correlate with poor prognosis in solid tumours. Methods In a retrospective study the prognostic implications of the extent of TN was evaluated in non-small cell lung cancer (NSCLC) and correlated with clinicopathological variables and expression of epidermal growth factor receptor, Bcl-2, p53 and matrix metalloproteinase-9 (MMP-9). Tissue specimens from 178 surgically resected cases of stage I-IIIA NSCLC with curative intent were studied. The specimens were routinely processed, formalin-fixed and paraffin-embedded. TN was graded as extensive or either limited or absent by two independent observers; disagreements were resolved using a double-headed microscope. The degree of reproducibility was estimated by re-interpreting 40 randomly selected cases after a 4 month interval. Results Reproducibility was attained in 36/40 cases, Kappa score=0.8 P<0.001. TN correlated with T-stage (P=0.001), platelet count (P=0.004) and p53 expression (P=0.031). Near significant associations of TN with N-stage (P=0.063) and MMP-9 expression (P=0.058) were seen. No association was found with angiogenesis (P=0.98). On univariate (P=0.0016) and multivariate analysis (P=0.023) TN was prognostic. Conclusion These results indicate that extensive TN reflects an aggressive tumour phenotype in NSCLC and may improve the predictive power of the TMN staging system. The lack of association between TN and angiogenesis may be important although these variables were not evaluated on serial sections. © 2002 Elsevier Science Ireland Ltd. All rights reserved.

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Purpose To evaluate carbonic anhydrase (CA) IX as a surrogate marker of hypoxia and investigate the prognostic significance of different patterns of expression in non-small-cell lung cancer (NSCLC). Methods Standard immunohistochemical techniques were used to study CA IX expression in 175 resected NSCLC tumors. CA IX expression was determined by Western blotting in A549 cell lines grown under normoxic and hypoxic conditions. Measurements from microvessels to CA IX positivity were obtained. Results CA IX immunostaining was detected in 81.8% of patients. Membranous (m) (P = .005), cytoplasmic (c) (P = .018), and stromal (P < .001) CA IX expression correlated with the extent of tumor necrosis (TN). The mean distance from vascular endothelium to the start of tumor cell positivity was 90 μm, which equates to an oxygen pressure of 5.77 mmHg. The distance to blood vessels from individual tumor cells or tumor cell clusters was greater if they expressed mCA IX than if they did not (P < .001). Hypoxic exposure of A549 cells for 16 hours enhanced CAIX expression in the nuclear and cytosolic extracts. Perinuclear (p) CA IX (P = .035) was associated with a poor prognosis. In multivariate analysis, pCA IX (P = .004), stage (P = .001), platelet count (P = .011), sex (P = .027), and TN (P = .035) were independent poor prognostic factors. Conclusion These results add weight to the contention that mCA IX is a marker of tumor cell hypoxia. The absence of CA IX staining close to microvessels suggests that these vessels are functionally active. pCA IX expression is representative of an aggressive phenotype. © 2003 by American Society of Clinical Oncology.

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Lung cancer patients face poor survival and experience co-occurring chronic physical and psychological symptoms. These symptoms can result in significant burden, impaired physical and social function and poor quality of life. This paper provides a review of evidence based interventions that support best practice supportive and palliative care for patients with lung cancer. Specifically, interventions to manage dyspnoea, one of the most common symptoms experienced by this group, are discussed to illustrate the emerging evidence base in the field. The evidence base for the pharmacological management of dyspnoea report systemic opioids have the best available evidence to support their use. In particular, the evidence strongly supports systemic morphine preferably initiated and continued as a once daily sustained release preparation. Evidence supporting the use of a range of other adjunctive non-pharmacological interventions in managing the symptom is also emerging. Interventions to improve breathing efficiency that have been reported to be effective include pursed lip breathing, diaphragmatic breathing, positioning and pacing techniques. Psychosocial interventions seeking to reduce anxiety and distress can also improve the management of breathlessness although further studies are needed. In addition, evidence reviews have concluded that case management approaches and nurse led follow-up programs are effective in reducing breathlessness and psychological distress, providing a useful model for supporting implementation of evidence based symptom management strategies. Optimal outcomes from supportive and palliative care interventions thus require a multilevel approach, involving interventions at the patient, health professional and health service level.

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Tumor hypoxia has been recognized to confer resistance to anticancer therapy since the early 20th century. More recently, its fundamental role in tumorigenesis has been established. Hypoxia-inducible factor (HIF)-1 has been identified as an important transcription factor that mediates the cellular response to hypoxia, promoting both cellular survival and apoptosis under different conditions. Increased tumor cell expression of this transcription factor promotes tumor growth In vivo and is associated with a worse prognosis in patients with non-small-cell lung cancer (NSCLC) undergoing tumor resection. The epidermal growth factor receptor (EGFR) promotes tumor cell proliferation and anglogenesis and inhibits apoptosis. Epidermal growth factor receptor expression increases in a stepwise manner during tumorigenesis and is overexpressed in > 50% of NSCLC tumors. This review discusses the reciprocal relationship between tumor cell hypoxia and EGFR. Recent studies suggest that hypoxia induces expression of EGFR and its ligands. In return, EGFR might enhance the cellular response to hypoxia by increasing expression of HIF-1α, and so act as a survival factor for hypoxic cancer cells. Immunohistochemical studies on a series of resected NSCLC tumors add weight to this contention by demonstrating a close association between expression of EGFR, HIF-1α, and:1 of HIF-1's target proteins, carbonic anhydrase IX. In this article we discuss emerging treatment strategies for NSCLC that target HIF-1, HIF-1 transcriptional targets, and EGFR.

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The aim of this phase I/II dose escalating study was to establish the maximum tolerated dose (MTD) of gemcitabine and paclitaxel given in combination in non-small cell lung cancer (NSCLC). 12 patients with stage IIIB and IV NSCLC received paclitaxel administered intravenously over 1 h followed by gemcitabine given over 30 min on days 1, 8 and 15 every 28 days. Pneumonitis was the principal side-effect observed with 4 patients affected. Of these, 1 experienced grade 3 toxicity after one cycle of treatment and the others had grade 2 toxicity. All 4 cases responded to prednisolone. No other significant toxicities were observed. Of the 8 evaluable patients, 3 had a partial response and 2 had minor responses. The study was discontinued due to this dose-limiting toxicity. The combination of paclitaxel and gemcitabine shows promising antitumour activity in NSCLC, however, this treatment schedule may predispose to pneumonitis. (C) 2000 Elsevier Science Ltd.

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Purpose A phase II study was designed to assess the efficacy and safety of Caelyx (liposomal doxorubicin) in patients with advanced or metastatic gastric cancer. Methods A total of 25 patients with gastric adenocarcinoma were treated with Caelyx 45 mg/m2 every 28 days as first-line therapy for advanced disease. Patients were treated until tumour progression or unacceptable toxicity. Results One patient was withdrawn from the study after experiencing a severe infusion reaction. Of the 24 evaluable patients, 1 had a partial response, 7 had stable disease and the others progressed. Side effects, in particular palmar-plantar erythrodysaesthesia and haematological toxicity, were minor. Conclusions We conclude that while this dose and schedule of Caelyx in this patient group is acceptable, further studies with this regimen cannot be recommended due to the lack of antitumour activity seen.

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Lung cancer is the most important cause of cancer-related mortality. Resectability and eligibility for treatment with adjuvant chemotherapy is determined by staging according to the TNM classification. Other determinants of tumour behaviour that predict disease outcome, such as molecular markers, may improve decision-making. Activation of the gene encoding human telomerase reverse transcriptase (hTERT) is implicated in the pathogenesis of lung cancer, and consequently detection of hTERT mRNA might have prognostic value for patients with early stage lung cancer. A cohort of patients who underwent a complete resection for early stage lung cancer was recruited as part of the European Early Lung Cancer (EUELC) project. In 166 patients expression of hTERT mRNA was determined in tumour tissue by quantitative real-time RT-PCR and related to that of a house-keeping gene (PBGD). Of a subgroup of 130 patients tumour-distant normal tissue was additionally available for hTERT mRNA analysis. The correlation between hTERT levels of surgical samples and disease-free survival was determined using a Fine and Gray hazard model. Although hTERT mRNA positivity in tumour tissue was significantly associated with clinical stage (Fisher's exact test p=0.016), neither hTERT mRNA detectability nor hTERT mRNA levels in tumour tissue were associated with clinical outcome. Conversely, hTERT positivity in adjacent normal samples was associated with progressive disease, 28% of patients with progressive disease versus 7.5% of disease-free patients had detectable hTERT mRNA in normal tissue [adjusted HR: 3.60 (1.64-7.94), p=0.0015]. hTERT mRNA level in tumour tissue has no prognostic value for patients with early stage lung cancer. However, detection of hTERT mRNA expression in tumour-distant normal lung tissue may indicate an increased risk of progressive disease.

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Purpose The role played by the innate immune system in determining survival from non-small-cell lung cancer (NSCLC) is unclear. The aim of this study was to investigate the prognostic significance of macrophage and mast-cell infiltration in NSCLC. Methods We used immunohistochemistry to identify tryptase+ mast cells and CD68+ macrophages in the tumor stroma and tumor islets in 175 patients with surgically resected NSCLC. Results Macrophages were detected in both the tumor stroma and islets in all patients. Mast cells were detected in the stroma and islets in 99.4% and 68.5% of patients, respectively. Using multivariate Cox proportional hazards analysis, increasing tumor islet macrophage density (P < .001) and tumor islet/stromal macrophage ratio (P < .001) emerged as favorable independent prognostic indicators. In contrast, increasing stromal macrophage density was an independent predictor of reduced survival (P = .001). The presence of tumor islet mast cells (P = .018) and increasing islet/stromal mast-cell ratio (P = .032) were also favorable independent prognostic indicators. Macrophage islet density showed the strongest effect: 5-year survival was 52.9% in patients with an islet macrophage density greater than the median versus 7.7% when less than the median (P < .0001). In the same groups, respectively, median survival was 2,244 versus 334 days (P < .0001). Patients with a high islet macrophage density but incomplete resection survived markedly longer than patients with a low islet macrophage density but complete resection. Conclusion The tumor islet CD68+ macrophage density is a powerful independent predictor of survival from surgically resected NSCLC. The biologic explanation for this and its implications for the use of adjunctive treatment requires further study. © 2005 by American Society of Clinical Oncology.