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Tutorials : Apr 1, 2008 ( )
Biobanks Can Make or Break Biomarkers
Quality Conformance Comes Into Play on Both the Front and Back End of Research Programs!--h2>
Previously, the NCI raised an alarm about the wide range of biospecimen quality used for research programs seeking novel biomarkers for diseases and the resulting tests that aid in the diagnosis of those diseases. During the NCI “Biospecimen Best Practices Forum” held in Seatle in January the warning was repeated.
Key Criteria for SelectionWhere selecting a biorepository would seem to be limited to selecting a resource provider, experience from biomarker-discovery programs shows a biobank provider becomes an essential partner in project development and plays a critical role in the speed of development and discovery. Ultimately, it is inextricably linked to the quality of the findings. It is not an exaggeration to say a good biorepository can accelerate research by several years and an unfortunate choice can have the opposite effect.
On the front end, a biorepository needs to be capable of providing valid specimens with informed consent firmly attached. Next, the biobank should hold a depth of clinical and demographic data on each specimen to verify initial discoveries and support validation. Finally, the bioresource should be able to offer a selection of same-patient tissues for cross-reference research to validate findings. In the case of blood-based collections, the availability of tightly matched healthy control samples is essential.
Ethical collection, specimen integrity, and data quality are three categories of investigation when looking at candidate biobanks. Evaluation should be conducted well ahead of launching research activities.
Equally critical but highly variable is data quality, which begins in the collection process and extends to the storage and processing capabilities of databanks. Uniformity of data procedures through standardization is the key challenge identified in the NCI Best Practices report.
The most important factor in this equation is the staff gathering the samples and their level of training and experience. For example, BioServe’s sera and tissue samples are drawn from multiple sites around the world and are collected in stages with significant variations in collection controls and standard operating procedures.
Extensive demographic and clinical data is ideally required for every sample, including the sample donor’s detailed medical history, family history, and the lifestyle choices. To illustrate the essential role of data quality and data retrieval for discovery programs, consider the case study from Phenomenome Discoveries in its search for a novel biomarker for colorectal cancer (CRC).
A targeted high-throughput screening method found that six novel molecules with formulae resembling the gamma isoform of vitamin E, tocopherol, were deficient in the serum from CRC patients and not controls. The resulting dataset of 900 accurate molecular masses was visualized using principal component analysis, which indicated a robust differentiation between controls and CRC cases.
The program rapidly achieved a milestone due to the ability to search datasets against multiple, matched biological materials in BioServe’s global repository to validate findings. Demonstrating that the novel metabolites are absent in both tissue samples and serum of diseased patients but not in matched healthy controls allowed a convincing correlation to be made.
Uniformity in Datasets
Uniformity in datasets supporting samples allowed the research team to tease out all factors contributing to the appearance of candidate biomarkers that were not related to the targeted disease state. Again applying biological materials from BioServe, a cross-reference investigation of diseased patient samples with other disease groups revealed that some of the markers are shared in both ovarian and breast cancer samples and therefore, not specific to CRC.
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