Details of HTA project
Last updated: 31 August 2010 - Next update due: 7 September 2010
Research type: |
Secondary Research (e.g. systematic review) |
Project title: |
The value of Positron-Emission-Tomography (PET) in pre-operative staging of colorectal cancer |
Project ref: |
08/65/02 |
Cost: |
£243,660 |
Chief Investigator : |
Professor David Weller, Head, School of Clin Sciences and Community Health, Division of Community Health Sciences, University of Edinburgh |
Start Date: |
April 2009 |
Estimated date of publication in HTA journal series: |
March 2011. This project is at the editorial review stage. Delays in the review process can cause the forecast publication date to be delayed. |
Plain English Summary |
Colo rectal cancer is the second most common cause of cancer death in the Western world. At the time of diagnosis and prior to surgery, cancers of the rectum and colon are assessed to establish the extent to which cancerous cells have spread within the large bowel and to other parts of the body. This process is known as pre-operative staging. Several diagnostic tests are used to assess the extent of local and distant disease: Ultrasound, Magnetic Resonance Imaging (MRI), Computerised Tomography (CT) and contrast enhanced Computerised Tomography (CT) scanning of the chest abdomen and pelvis as well as a full blood count and biochemical profile can all inform the prognosis prior to surgical resection. Imaging modalities for pre-operative staging are less than perfect: and there is a need to evaluate new imaging modalities for use in the pre-operative work-up. As well as being valuable to inform post-operative decision-making about adjuvant therapy such as chemotherapy, pre-operative imaging techniques may help clinicians reach more accurate prognoses for patients. F-flurodeoxyglucose Positron Emission Tomography (FDG-PET) is increasingly being used with CT scanning during the staging-process and there is some evidence that this diagnostic test confers potential benefits for patients with cancer by improving the accuracy of the prognostic assessment which could lead to changes in their management. However, the value from this expensive additional test is not clear. The proposed research seeks to summarise the benefits, harms and costs of PET/CT when used to inform clinicians about the likely course of cancer of the bowel. We propose to use a systematic review of the literature to help us achieve the research objectives. In this way we will be able to judge the quality of studies conducted by other researchers and to use their published data in our analysis. There are therefore no ethical issues involved in our research because it uses data from patients in other studies. Using the data we will calculate the accuracy of PET/CT and also the effect that this new test has on the way patients recieve care; whether there are changes in the number of patients who go on to have surgery or chemotherapy for example. We will also be able to calculate the costs of these different scenarios to work out the costs and benefits from this new way of making assessments. To avoid bias, it is important to find as many studies as possible - something we know is difficult to do with these type of studies - and this research addresses this problem: We will design several searches to help us find as many reports of studies which include people with colorectal cancer and test them to find theliterature searches which perform best. This kind of research needs a team of people with a variety of skills and backgrounds and we are fortunate to haveall the skills necessary to conduct this research in our team members. The medically qualified doctors ioncvolved in making the application have all worked with patients with cancer for many years and have all received funding for their research from Governments in the United Kingdom and the United States of America as well as medical charities. The health researchers are highly skilled too and have in depth knowledge of the methods needed to achieve valid results; the information specialists, statistician and health economist are all experts in their field. The cost of supporting the team conducting the research has been very carefully considered to ensure that it is completed to the highest scientific standard and the research outputs reach those most likely to benefit. |
Project Abstract: |
Design: A systematic review with economic modelling Search Strategy Studies will be identified through searching a range of electronic databases shown to yield diagnostic test accuracy studies, including MEDLINE, EMBASE , Science Citation Index, BIOSIS and Lilacs. Studies will also be identified through contacting experts in the field. A search of economic literature will be conducted to inform the development of the economic model; we will search relevant economic databases e.g.. NHS Economic Evaluation Database (NHS EED). We would like to take the opportunity this project offers to enhance the identification of studies for the review by handsearching journals to create a gold standard (if the gold standard is large enough to allow splitting into a test and validation set) against which to test search filter performance and add significant value to this systematic review by including a study that will improve understanding of effective database searching for diagnostic accuracy studies. Review Strategy We will include studies reporting outcomes from people with a diagnosis of cancer of the colon or rectum who have a PET/CT scan and are being considered for curative surgery in secondary care settings. We will include studies of patients with primary, recurrent and metatastic disease in cohort studies which describe evaluations of PET/CT imaging and we will also consider data from randomised controlled trials RCTs in which patients with colorectal cancer of have been randomised to receive pre-operative staging using PET/CT versus outcomes from patients who were not. We will include studies published in all languages. We are primarily interested in all data relating to diagnostic accuracy and secondarily of outcomes relating to changes in patient management (e.g. change from curative to palliative care or use of adjuvant therapies). Quality assessment will be conducted using items appropriate items adapted from the QUADAS tool. Results of the evaluation of the accuracy of PET/CT will be analysed in the following way: Results of the evaluation of the accuracy of PET/CT will be analysed in the following way: For each study the range in sensitivity, specificity and likelihood ratios (of both positive and negative tests results) will be calculated, together with possible ranges in positive and negative predictive values. Diagnostic odds ratios (DOR) will be calculated. If the data do not support the summary ROC curve model, separate meta-analyses of sensitivity and specificity will be presented, using fixed or random effects as appropriate depending on the degree of heterogeneity. In order to estimate the costs, effectiveness and cost-effectiveness of PET/CT compared with other modes of diagnosis and staging in colorectal cancer, a probabilistic decision model will be constructed. Expected Output of Research It is our intention to submit a copy of the report in RevMan (Reference Manager) to the Cochrane Collaboration Colorectal Cancer Review Group in addition to the final report to the HTA. We will also publish the findings of the research in peer-reviewed journals. Expertise in team The research team collectively possess the skills necessary to deliver the research objectives (page 7 of the detailed project description) Project timetable: we anticipate this work will take one year to complete (Jan 2009-December 2009). |
Project Protocol: |
Project protocol (pdf format, 122 kbytes) |
URL of this page: |
http://www.hta.ac.uk/1812 |
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