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Unformatted text preview: Articles 678 http://oncology.thelancet.com Vol 6 September 2005 Introduction A hallmark of bladder cancer is its variable prognosis. About 70% of superficial (Ta and T1) tumours recur, and 1020% become invasive. 15 Tumours that are invasive have a high risk of progression despite radical cystectomy and other treatments. 6 Conventional prognostic factors, such as tumour stage, grade, size, and multifocality, do not accurately predict the clinical outcome of many patients with bladder cancer, 15 and widespread efforts have been made to identify markers that predict recurrence and progression of the disease, response to treatment, and survival. P53 is the most frequently involved gene in cancer in human beings; its product, P53, has a fundamental role in the control of cell proliferation, apoptosis, and genetic stability. 7,8 Overexpression of P53 in the nucleus, detected by use of immunohistochemical techniques (figure 1), is commonly regarded as a surrogate marker for P53 mutation, and has been the most widely investigated molecular marker in bladder cancer in the past decade. 4,9,10 The first important report 11 which showed that P53 changes were predictive of outcome in patients with bladder cancer undergoing cystectomy was published by Esrig and colleagues in 1994 . We have done a systematic review of papers published in the past decade on changes in P53 and their effects on bladder-cancer prognosis. We aimed to: assess the quality of published studies; summarise the accuracy of changes in P53 in prediction of recurrence, progression, and mortality in patients with bladder cancer; identify factors that could affect the assessment of the prognostic role of changes in P53; and do a meta-analysis of available estimates. Unlike previous reviews, 10,1215 we have included all identified published reports, have assessed potential sources of heterogeneity contributing to conicting results, and applied quantitative methods to summarise data. Methods Search strategy and selection criteria We did a systematic review of original articles published between January, 1993, and July, 2003, in English, Spanish, German, French, Italian, and Portuguese that analysed the prognostic role of P53 overexpression or P53 mutation in patients with bladder cancer. We identified 698 articles from a search of MEDLINE, CancerLit, and EMBASE databases using the keywords P53 and bladder neoplasms-in-human. The number of studies was reduced to 430 by limiting the search with the keywords prognosis or prognostic or survival or recurrence or progression. We also searched the reference list of all selected articles and assessed each abstract. Reviews, non-original articles, and studies on transitional carcinomas not arising in the bladder were excluded. To avoid duplicate data, we identified articles that included the same cohort of patients by reviewing interstudy similarity in the country in which the study was done, investigators in the study, source of patients,...
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This note was uploaded on 02/23/2011 for the course HTEC 50 taught by Professor Hassel,patricia during the Spring '11 term at DeAnza College.
- Spring '11