Assessment of the extent of unpublished studies in prognostic factor research: a systematic review of p53 immunohistochemistry in bladder cancer as an example

Objectives When study groups fail to publish their results, a subsequent systematic review may come to incorrect conclusions when combining information only from published studies. p53 expression measured by immunohistochemistry is a potential prognostic factor in bladder cancer. Although numerous studies have been conducted, its role is still under debate. The assumption that unpublished studies too harbour evidence on this research topic leads to the question about the attributable effect when adding this information and comparing it with published data. Thus, the aim was to identify published and unpublished studies and to explore their differences potentially affecting the conclusion on its function as a prognostic biomarker. Design Systematic review of published and unpublished studies assessing p53 in bladder cancer in Germany between 1993 and 2007. Results The systematic search revealed 16 studies of which 11 (69%) have been published and 5 (31%) have not. Key reason for not publishing the results was a loss of interest of the investigators. There were no obviously larger differences between published and unpublished studies. However, a meaningful meta-analysis was not possible mainly due to the poor (ie, incomplete) reporting of study results. Conclusions Within this well-defined population of studies, we could provide empirical evidence for the failure of study groups to publish their results that was mainly caused by loss of interest. This fact may be coresponsible for the role of p53 as a prognostic factor still being unclear. We consider p53 and the restriction to studies in Germany as a specific example, but the critical issues are probably similar for other prognostic factors and other countries

Effect of oral lactulose on clinical and immunohistochemical parameters in patients with inflammatory bowel disease: a pilot study

<p>Abstract</p> <p>Background</p> <p>The prebiotic potential of lactulose is well established and preclinical studies demonstrated a protective effect of lactulose in murine models of colitis. The aim of the present study was to investigate the clinical and histological efficacy of lactulose in patients with inflammatory bowel disease (IBD), for which probiotic therapy yielded promising results.</p> <p>Methods</p> <p>Patients were treated with standard medication alone or combined with 10 g lactulose daily as adjuvant therapy for 4 months. Clinical efficacy of treatment was assessed using clinical activity indices, a quality of life index (IBDQ), endoscopic scores, defecation frequency and monitoring corticosteroid medication. Orsomucoid, alpha1-antitrypsin and other laboratory parameters were determined. In addition, in some participants colonic biopsies were analyzed with haematoxylin-eosin staining or with antibodies against HLA-DR, CD68, IgA and CD3, and evaluated systematically. All measurements were performed both at enrolment and at the end of the trial.</p> <p>Results</p> <p>14 patients presenting ulcerative colitis (UC) and 17 patients presenting Crohn's disease (CD), most of them in a clinically active state, were enrolled in this pilot study. After 4 month no significant improvement of clinical activity index, endoscopic score or immunohistochemical parameters was observed in CD or UC patients receiving lactulose in comparison to the control group. However, significant improvement of quality of life was observed in UC patients receiving lactulose compared to the control group (p = 0.04).</p> <p>Conclusion</p> <p>The findings of the present pilot study indicate that oral lactulose has no beneficial effects in IBD patients in particular with regard to clinical activity, endoscopic score or immunohistochemical parameters. The importance of the beneficial effect of lactulose in UC patients regarding the quality of life needs further evaluation in larger controlled clinical trials.</p> <p>Trial registration</p> <p>Current Controlled Trials ISRCTN92101486</p

Prospective Observational Study of Pazopanib in Patients with Advanced Renal Cell Carcinoma (PRINCIPAL Study)

Background: Real-world data are essential to accurately assessing efficacy and toxicity of approved agents in everyday practice. PRINCIPAL, a prospective, observational study, was designed to confirm the real-world safety and efficacy of pazopanib in patients with advanced renal cell carcinoma (RCC). Subjects, Materials, and Methods: Patients with clear cell advanced/metastatic RCC and a clinical decision to initiate pazopanib treatment within 30 days of enrollment were eligible. Primary objectives included progression-free survival (PFS), overall survival (OS), objective response rate (ORR), relative dose intensity (RDI) and its effect on treatment outcomes, change in health-related quality of life (HRQoL), and safety. We also compared characteristics and outcomes of clinical-trial-eligible (CTE) patients, defined using COMPARZ trial eligibility criteria, with those of non-clinical-trial-eligible (NCTE) patients. Secondary study objectives were to evaluate clinical efficacy, safety, and RDI in patient subgroups. Results: Six hundred fifty-seven patients were enrolled and received ≥1 dose of pazopanib. Median PFS and OS were 10.3 months (95% confidence interval [CI], 9.2–12.0) and 29.9 months (95% CI, 24.7 to not reached), respectively, and the ORR was 30.3%. HRQoL showed no or little deterioration over time. Treatment-related serious adverse events (AEs) and AEs of special interest occurred in 64 (9.7%), and 399 (60.7%) patients, respectively. More patients were classified NCTE than CTE (85.2% vs. 14.8%). Efficacy of pazopanib was similar between the two groups. Conclusion: PRINCIPAL confirms the efficacy and safety of pazopanib in patients with advanced/metastatic RCC in a real-world clinical setting. Implications for Practice: PRINCIPAL is the largest (n = 657) prospective, observational study of pazopanib in patients with advanced/metastatic renal cell carcinoma, to the authors’ knowledge. Consistent with clinical trial results that often contain specific patient types, the PRINCIPAL study demonstrated that the effectiveness and safety of pazopanib is similarly safe and effective in patients with advanced kidney cancer in a real-world clinical setting. The PRINCIPAL study showed that patients with advanced kidney cancer who are treated with first-line pazopanib generally do not show disease progression for approximately 10 months and generally survive for nearly 30 months

Prognostic markers in cancer: the evolution of evidence from single studies to meta-analysis, and beyond

In oncology, prognostic markers are clinical measures used to help elicit an individual patient's risk of a future outcome, such as recurrence of disease after primary treatment. They thus facilitate individual treatment choice and aid in patient counselling. Evidence-based results regarding prognostic markers are therefore very important to both clinicians and their patients. However, there is increasing awareness that prognostic marker studies have been neglected in the drive to improve medical research. Large protocol-driven, prospective studies are the ideal, with appropriate statistical analysis and clear, unbiased reporting of the methods used and the results obtained. Unfortunately, published prognostic studies rarely meet such standards, and systematic reviews and meta-analyses are often only able to draw attention to the paucity of good-quality evidence. We discuss how better-quality prognostic marker evidence can evolve over time from initial exploratory studies, to large protocol-driven primary studies, and then to meta-analysis or even beyond, to large prospectively planned pooled analyses and to the initiation of tumour banks. We highlight articles that facilitate each stage of this process, and that promote current guidelines aimed at improving the design, analysis, and reporting of prognostic marker research. We also outline why collaborative, multi-centre, and multi-disciplinary teams should be an essential part of future studies

Altered postprandial motility in chronic pancreatitis: role of malabsorption

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