title: Statistical strategies to improve the efficiency of molecular studies of colorectal cancer prognosis.
abstract: The evaluation of tumour molecular markers may be beneficial in prognosis and predictive in therapy. We develop a stopping rule approach to assist in the efficient utilisation of resources and samples involved in such evaluations. This approach has application in determining whether a specific molecular marker has sufficient variability to yield meaningful results after the evaluation of molecular markers in the first n patients in a study of sample size N (n</=N). We evaluated colorectal tumours for mutations (microsatellite instability, K-ras, B-raf, PI3 kinase, and TGFbetaR-II) by PCR and protein markers (Bcl2, cyclin D1, E-cadherin, hMLH1, ki67, MDM2, and P53) by immunohistochemistry. Using this method, we identified and abandoned potentially uninformative molecular markers in favour of more promising candidates. This approach conserves tissue resources, time, and money, and may be applicable to other studies.
authors.affiliation: Cancer Research and Biostatistics (CRAB), 1730 Minor Ave Suite 1900, Seattle, WA 98101, USA. pingpingq@crab.org
authors.forename: P
authors.initials: P
authors.lastname: Qu
authors.forename: H
authors.initials: H
authors.lastname: Chu
authors.forename: J G
authors.initials: JG
authors.lastname: Ibrahim
authors.forename: J
authors.initials: J
authors.lastname: Peacock
authors.forename: X J
authors.initials: XJ
authors.lastname: Shen
authors.forename: J
authors.initials: J
authors.lastname: Tepper
authors.forename: R S
authors.initials: RS
authors.lastname: Sandler
authors.forename: T O
authors.initials: TO
authors.lastname: Keku
mesh_terms: D015415:Biomarkers; D015179:Colorectal Neoplasms / Q000453:epidemiology* / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D009154:Mutation / Q000235:genetics; D011379:Prognosis; D011506:Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D015415:Biomarkers; D011506:Proteins