Tumour Biology (tumour + biology)

Distribution by Scientific Domains
Distribution within Medical Sciences


Selected Abstracts


Interaction of tumour biology and tumour burden in determining outcome after hepatic resection for colorectal metastases

HPB, Issue 2 2010
Dhanny Gomez
Abstract Aims:, To determine the outcome of colorectal liver metastasis (CRLM) patients based on tumour burden, represented by tumour number and size, and tumour biology as assessed by an inflammatory response to tumour (IRT) and margin positivity. Methods:, Data were collated from CRLM patients undergoing resection from January 1993 to March 2007. Patients were divided into: low (,3 metastases and/or ,3 cm); moderate (4,7 metastases and/or >3,,5 cm); and high (,8 metastases and/or >5 cm) tumour burden. Results:, Seven hundred and five patients underwent resection, of which 154 (21.8%), 262 (37.2%) and 289 (41.0%) patients were in the low, moderate and high tumour burden groups, respectively. The 5-year disease-free (P < 0.001) and overall (P < 0.001) survival were significantly different between the groups. IRT (P < 0.001), extent of resection (P < 0.001) and margin (P < 0.001) also differed between the groups. Sub-group analysis revealed that IRT was the only adverse predictor for disease-free and overall survival in the low group. In the moderate group, IRT predicted poorer disease-free survival on multi-variate analysis. In the high group, R1 resection and transfusion were predictors of poorer disease-free survival and age ,65 years, R1 resection and IRT were adverse predictors of overall survival. Conclusion:, Resection margin influenced the outcome of patients with high tumour burden, hence the importance of achieving clear margins. IRT influenced the outcome of patients with less aggressive disease. [source]


MYCN regulates oncogenic MicroRNAs in neuroblastoma

INTERNATIONAL JOURNAL OF CANCER, Issue 3 2008
Johannes H. Schulte
Abstract MYCN amplification is a common feature of aggressive tumour biology in neuroblastoma. The MYCN transcription factor has been demonstrated to induce or repress expression of numerous genes. MicroRNAs (miRNA) are a recently discovered class of short RNAs that repress translation and promote mRNA degradation by sequence-specific interaction with mRNA. Here, we sought to analyse the role of MYCN in regulation of miRNA expression. Using a miRNA microarray containing 384 different miRNAs and a set of 160 miRNA real-time PCR assays to validate the microarray results, 7 miRNAs were identified that are induced by MYCN in vitro and are upregulated in primary neuroblastomas with MYCN amplification. Three of the seven miRNAs belong to the miR-106a and miR-17 clusters, which have previously been shown to be regulated by c-Myc. The miR-17,92 polycistron also acts as an oncogene in haematopoietic progenitor cells. We show here that miR-221 is also induced by MYCN in neuroblastoma. Previous studies have reported miR-221 to be overexpressed in several other cancer entities, but its regulation has never before been associated with Myc. We present evidence of miRNA dysregulation in neuroblastoma. Additionally, we report miRNA induction to be a new mechanism of gene expression downregulation by MYCN. © 2007 Wiley-Liss, Inc. [source]


Type II nitric oxide synthase (NOS2) expression correlates with lymph node status in oral squamous cell carcinoma

JOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 3 2001
Peter A. Brennan
Abstract: In tumour biology, nitric oxide (NO) has a complex array of concentration-dependent actions, including both inhibitory and promoting effects. It is thought that the levels of NO found in many human cancers lead to enhanced angiogenesis and tumour dissemination. In the current study, we assessed the immunohistochemical expression of the enzyme type II nitric oxide synthase (NOS2) in 41 cases of oral squamous cell carcinoma and correlated the findings with lymph node status. A significant relationship was found between NOS2 expression and lymph node metastasis (P<0.0002). Furthermore, lymph node metastasis correlated with the degree and intensity of staining seen (P<0.001). No correlation was found between the size of the primary tumour, degree of tumour differentiation or smoking status and NOS2 staining. Western blotting confirmed NOS2 protein expression in select cases. As with many other human tumours, NOS2 is not a ubiquitous finding in oral cancer. Its expression may be of value in assessing lymph node status prior to surgery, and it represents a target for possible therapeutic manipulation. [source]


Histomorphometry of brain tumours

NEUROPATHOLOGY & APPLIED NEUROBIOLOGY, Issue 4 2004
R. Nafe
In this review, the results of previous histomorphometric studies of brain tumours are summarized and discussed with respect to their potential value for diagnostic purposes and for tumour research. In the majority of these studies, human gliomas were investigated. In a few studies, human meningiomas and other human or experimental tumour types were investigated. A computerized image analysis system was used for the morphometric analyses in most studies. The three main histologic structures examined were tumour cell nuclei, nucleolar organizer regions and tumour vessels. The current state of knowledge provides evidence that a diagnostic benefit could be provided by histomorphometric investigations of brain tumours, especially for grading of gliomas and with respect to independent prognostic information. Additional studies are necessary to delineate the spectrum of histomorphometric parameters and the investigation of their prognostic significance for cases with the same tumour type and tumour grade. Together with many recently published observations in this field, this review shows that histomorphometry is an important approach towards the investigation of brain tumour biology. [source]


Current and emerging concepts in tumour metastasis,

THE JOURNAL OF PATHOLOGY, Issue 1 2010
Caroline Coghlin
Abstract Disseminated cancer accounts for most deaths due to malignancy. Despite this, research has focused predominantly on tumour development and progression at the primary site. Recently, attention has shifted towards the field of tumour metastasis. Several new and exciting concepts that have emerged in the past few years may shed light on this complex area. The established canonical theory of tumour metastasis, as a process emerging from a stepwise accumulation of genetic events fuelled by clonal evolution, has been challenged. New evidence suggests that malignant cells can disseminate at a much earlier stage than previously recognized in tumourigenesis. These findings have direct relevance to clinical practice and shed new light on tumour biology. Gene-profiling studies support this theory, suggesting that metastatic ability may be an innate property shared by the bulk of cells present early in a developing tumour mass. There is a growing recognition of the importance of host factors outside the primary site in the development of metastatic disease. The role of the ,pre-metastatic niche' is being defined and with this comes a new understanding of the function of bone marrow-derived progenitor cells in directing the dissemination of malignant cells to distant sites. Current research has highlighted the crucial roles played by non-neoplastic host cells within the tumour microenvironment in regulating metastasis. These new concepts have wide-ranging implications for our overall understanding of tumour metastasis and for the development of cancer therapeutics. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source]


Making use of the primary tumour

BIOESSAYS, Issue 1 2003
Arnold Baars
Surgical resection of a primary tumour is often not sufficient to cure a patient. Even when no residual cancer can be detected at time of surgery, metastases may appear in the following years, which indicates that the primary tumour had apparently spread before surgery. Following surgery, systemic chemotherapy may be used to eradicate micro-metastatic disease. Here we present two unconventional strategies that implement new insights into tumour biology and tumour immunology in the treatment of patients with cancer. Both experimental strategies use the individual characteristics of the patient's primary tumour to optimise the control of life-threatening micro-metastases. We aim to modulate the patient's adaptive immune system, targeting it towards the patient's own tumour cells to eradicate residual disease following local treatment. In one approach, this is done by autologous tumour cell vaccinations as adjuvant treatment for colon cancer patients and, in a second approach, by giving chemo-imunotherapy before local treatment to women with locally advanced breast cancer. BioEssays 25:79,86, 2003. © 2002 Wiley Periodicals, Inc. [source]


A predictive model for local recurrence after transanal endoscopic microsurgery for rectal cancer,,

BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 3 2009
S. P. Bach
Background: The outcome of local excision of early rectal cancer using transanal endoscopic microsurgery (TEM) lacks consensus. Screening has substantially increased the early diagnosis of tumours. Patients need local treatments that are oncologically equivalent to radical surgery but safer and functionally superior. Methods: A national database, collated prospectively from 21 regional centres, detailed TEM treatment in 487 subjects with rectal cancer. Data were used to construct a predictive model of local recurrence after TEM using semiparametric survival analyses. The model was internally validated using measures of calibration and discrimination. Results: Postoperative morbidity and mortality were 14·9 and 1·4 per cent respectively. The Cox regression model predicted local recurrence with a concordance index of 0·76 using age, depth of tumour invasion, tumour diameter, presence of lymphovascular invasion, poor differentiation and conversion to radical surgery after histopathological examination of the TEM specimen. Conclusion: Patient selection for TEM is frequently governed by fitness for radical surgery rather than suitable tumour biology. TEM can produce long-term outcomes similar to those published for radical total mesorectal excision surgery if applied to a select group of biologically favourable tumours. Conversion to radical surgery based on adverse TEM histopathology appears safe for p T1 and p T2 lesions. Copyright © 2009 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source]


Oncogenes in thyroid cancer

CLINICAL OTOLARYNGOLOGY, Issue 5 2003
D.S. Kim
There have been significant advances in our understanding of carcinogenesis at the molecular level over the last 25 years. Oncogenes are of major interest as part of our search for knowledge surrounding the aetiology of cancer. There are several oncogenes associated with thyroid cancer. Detailed investigation of the nature and function of these tumour genes has provided important insights into both the tumour biology and the complex biochemical pathways of normal cellular functioning. Our knowledge of oncogene biology offers the hope of better diagnostic, therapeutic and prognostic modalities in our fight against this and other common cancers. Development of specific thyroid tumour markers and gene therapy is now a realistic prospect to supplement our present armamentarium of surgery and radiotherapy. This review aims to outline the pertinent information gained so far from studies of these oncogenes and provides both clinical relevance and fuel for further interest amongst the ENT thyroid community in this exciting area of research. [source]