Abbreviated Name

Colon Team Project #2

Lead Investigator

Schoen, Robert E. — University of Pittsburgh Cancer Institute

Coordinating Investigator

Schoen, Robert E. — University of Pittsburgh Cancer Institute

Involved Investigators

• Markowitz, Sanford — Case Western Reserve University
• Lampe, Paul — Fred Hutchinson Cancer Center
• Grady, William — Fred Hutchinson Cancer Center
• Schoen, Robert E. — University of Pittsburgh Cancer Institute
• Hanash, Samir — The University of Texas MD Anderson Cancer Center
• Srivastava, Sudhir — National Cancer Institute
• Getzenberg, Robert — Johns Hopkins University

Abstract

No abstract availalbe.

Aims

1.   Characterization of intra-subject reproducibility and variability: To assess the reproducibility and variability of marker expression within individuals, we will evaluate marker expression in duplicate samples from the same region of the colon and in 4 different sites around the colon, the rectum, left, transverse and right colon. 2.   Characterization of inter-subject variability in marker expression by disease phenotype: To characterize the inter-subject variability in marker expression by disease phenotype, we will compare marker expression in normal colonic mucosa between subjects with and without adenomatous polyps. 3.   Characterization of the relationship of marker expression and long-term adenoma recurrence: To examine the relationship between marker expression and long-term adenoma recurrence, we will compare marker expression among subjects with baseline adenomas who have a recurrence of adenomatous polyps compared to those who do not.

Analytic Method

Analysis Plan: A mixed effects linear model will be used to estimate means and between-patient and within-segment variance parameters; location of biopsy will be considered a fixed effect, and patient a random effect. The within-segment variance is an estimator of assay reliability, while the difference in means between segments indicates how well rectal or distal colon values agree with transverse and proximal colon values. The between-patient variances can be used to calculate effect sizes used in the design of subsequent trials. The biopsy location effect is an indicator of the consistency of the biomarkers throughout the colon; because these are normal tissue, not adenoma, biopsies, significant variation between biopsy sites would have implications for sampling strategies, and could indicate non-specificity of the marker for adenoma. Using Monte Carlo simulation of the proposed design, we determined that, in 90% of the simulated trials, the estimated between-patient variance was within 70% of the true value, and the estimated within-segment variance was within 28% of its true value. The power to test the null hypothesis of no difference in means between segments was in excess of 80% if the effect size (difference between segment means divided by within-segment standard deviation) was 0.8 or greater.

Publications

• No publications available at this time for this protocol.

Biomarkers

• No biomarkers available at this time for this protocol.

Data Collections

• No data collections available at this time for this protocol.

 Team Project

Start Date

Sep 1 2011

Estimated Finish Date

Sep 1 2014

Protocol ID

348

Protocol Type

Collaboration

Fields of Research

• Genomics
• Proteomics

Collaborative Group

G.I. and Other Associated Cancers Research Group

Cancer Types

• Malignant neoplasm of colon

Phased Status

1