157 research outputs found

    A Study of Thymidylate Synthase Expression as a Biomarker for Resectable Colon Cancer: Alliance (Cancer and Leukemia Group B) 9581 and 89803.

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    PurposeTumor levels of thymidylate synthase (TS), a target of 5-fluorouracil (5-FU)-based chemotherapy for colorectal cancer, have been studied as a predictive or prognostic biomarker with mixed results.Patients and methodsTumor TS levels were prospectively evaluated in two adjuvant therapy trials for patients with resected stage II or III colon cancer. TS expression was determined by standard immunohistochemistry and by automated quantitative analysis. Tumor mismatch repair deficiency (MMR-D) and BRAF c.1799T > A (p.V600E) mutation status were also examined. Relationships between tumor TS, MMR-D, and BRAF mutation status, overall survival (OS), and disease-free survival (DFS) were investigated in the subset of stage III patients.ResultsPatients whose tumors demonstrated high TS expression experienced better treatment outcomes, with DFS hazard ratio (HR) = 0.67, 95% confidence interval (CI) = 0.53, 0.84; and OS HR = 0.68, 95% CI = 0.53, 0.88, for high versus low TS expression, respectively. No significant interaction between TS expression and stage was observed (DFS: interaction HR = 0.94; OS: interaction HR = 0.94). Tumors with high TS expression were more likely to demonstrate MMR-D (22.2% vs. 12.8%; p =  .0003). Patients whose tumors demonstrated both high TS and MMR-D had a 7-year DFS of 77%, compared with 58% for those whose tumors had low TS and were non-MMR-D (log-rank p =  .0006). Tumor TS expression did not predict benefit of a particular therapeutic regimen.ConclusionThis large prospective analysis showed that high tumor TS levels were associated with improved DFS and OS following adjuvant therapy for colon cancer, although tumor TS expression did not predict benefit of 5-FU-based chemotherapy. The Oncologist 2017;22:107-114Implications for Practice: This study finds that measurement of tumor levels of thymidylate synthase is not helpful in assigning specific adjuvant treatment for colorectal cancer. It also highlights the importance of using prospective analyses within treatment clinical trials as the optimal method of determining biomarker utility

    Lithium intercalation in nanostructured thin films of a mixed-valence layered vanadium oxide using an ionic liquid electrolyte

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    AbstractNanostructured thin films of a mixed-valence, layered vanadium oxide were prepared using layer-by-layer deposition. The thin films were characterized by electronic (UV–vis) spectroscopy, quartz crystal microbalance, profilometry and scanning electron microscopy techniques. The highest charge capacity was obtained for films that consisted of 25 bilayers. The electrochemical characterization of the films was performed in conventional organic solvent and ionic liquid (IL) based electrolytes. The results revealed better performance, in terms of stability during consecutive charge/discharge cycles, when ILs were employed. This can be attributed to several factors, including reduced mechanical stress caused by insertion of more than 1 mol of Li+ per mol of V5+ in the film structure, decrease of crystallinity in the electrode material during the first few charge/discharge cycles and/or formation of a more compatible SEI. Nanostructured thin films of layered vanadium oxide prepared using layer-by-layer deposition showed potential for applications in lithium microbatteries

    Microsatellite Instability and Loss of Heterozygosity at Chromosomal Location 18q: Prospective Evaluation of Biomarkers for Stages II and III Colon Cancer—A Study of CALGB 9581 and 89803

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    Colorectal cancer (CRC) develops as a result of a series of accumulated genomic changes that produce oncogene activation and tumor suppressor gene loss. These characteristics may classify CRC into subsets of distinct clinical behaviors

    p27Kip1 in Stage III Colon Cancer: Implications for Outcome following Adjuvant Chemotherapy in Cancer and Leukemia Group B Protocol 89803

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    In retrospective studies, loss of p27Kip1 (p27), a cyclin dependent kinase inhibitor, has been associated with poor prognosis following colorectal cancer treatment. In a prospective study, we validated this relationship in patients enrolled on a trial of adjuvant chemotherapy for Stage III colon cancer

    Heparanase expression is a prognostic indicator for postoperative survival in pancreatic adenocarcinoma

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    Pancreatic ductal adenocarcinoma has a median survival of less than 6 months from diagnosis. This is due to the difficulty in early diagnosis, the aggressive biological behaviour of the tumour and a lack of effective therapies for advanced disease. Mammalian heparanase is a heparan-sulphate proteoglycan cleaving enzyme. It helps to degrade the extracellular matrix and basement membranes and is involved in angiogenesis. Degradation of extracellular matrix and basement membranes as well as angiogenesis are key conditions for tumour cell spreading. Therefore, we have analysed the expression of heparanase in human pancreatic cancer tissue and cell lines. Heparanase is expressed in cell lines derived from primary tumours as well as from metastatic sites. By immunohistochemical analysis, it is preferentially expressed at the invading edge of a tumour at both metastatic and primary tumour sites. There is a trend towards heparanase expression in metastasising tumours as compared to locally growing tumours. Postoperative survival correlates inversely with heparanase expression of the tumour reflected by a median survival of 34 and 17 month for heparanase negative and positive tumours, respectively. Our results suggest, that heparanase promotes cancer cell invasion in pancreatic carcinoma and could be used as a prognostic indicator for postoperative survival of patients
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