ISSN:
0730-2312
Keywords:
biological markers
;
cancer
;
gastric cancer
;
genetics
;
log rank test
;
lung cancer
;
molecular biology
;
molecular epidemiology
;
polymorphisms
;
p53
;
prevention
;
power
;
sample size
;
survival analyses
;
trials
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
Cancer is currently regarded to be the phenotypic expression of an accumulation of heritable alterations in the regulators of cell growth and differentiation. Though detailed knowledge of the sequence and in vivo mechanistic effects of these alterations is rudimentary for most, if not all, cancers, their identification does offer the potential for classifying groups of individuals who are heterogeneous with respect to their cancer risks, into more nearly homogeneous subgroups. In this paper, we illustrate the value of using markers, which we define as any manifestation of cellular molecular diversity, to increase subgroup homogeneity. In the context of time-to-event data, we demonstrate for both somatic mutations (acquired p.53 abnormalities in gastric mucosal cells) and inherited polymorphisms (polymorphisms in the phase 1 and 2 detoxifying enzymes) how knowledge regarding the population frequency of the marker, the effect of the marker on the risk of cancer development, and/or the effect of the marker on response to therapy, can be used to plan and analyze such trials. Using as paradigms demographic features of the recently begun Shandong precancerous gastric lesion intervention trial, and the recently completed α-tocopherol β-carotene (ATBC) lung cancer prevention study, we review the information, assumptions, and mathematical structure required for planning cancer prevention trials. We graphically demonstrate how informative markers make available strategies for selection, stratification, and optimal weighing, which, when properly implemented, increase the power of tests of effective cancer prevention agents. J. Cell. Biochem. 25S:69-79. © 1997 Wiley-Liss, Inc. This article is a U.S. Government work and, as such, is in the public domain in the United States of America.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
