AICR / WCRF Annual Research Conference Washington DC Diet, Nutrition, and Cancer Mechanisms The Role of Clinical Trials Steven K. Clinton, MD, PhD November 8, 2013
AICR s 2013 Annual Research Conference on Food, Nutrition, Physical Activity and Cancer November 7-8, 2913 Hyatt Regency Bethesda Name of Speaker: Steven K. Clinton, MD, PhD 2
What is a clinical trial? a prospective study involving human subjects designed to answer specific questions about the effects or impact of particular biomedical or behavioral interventions; these may include drugs, treatments, devices, or behavioral or nutritional strategies - NIH / NCI Definition 3
Biblical Description of a Clinical Trial Daniel 1:12-16 Fragment of Daniel s Protocol 4
The First Clinical Trial in Nutrition Please test your servants for ten days: Give us nothing but vegetables to eat and water to drink. Then compare our appearance with that of the young men who eat the royal food, and treat your servants in accordance with what you see. So he consented them and tested them for ten days. At the end of the ten days they looked healthier and better nourished than any of the young men who ate the royal food. So the guard took away their choice food and the wine they were to drink and gave them vegetables instead. Daniel 1:12-16 5
A definitive trial. The Selenium and Vitamin E Cancer Prevention Trial (SELECT), a Phase III, randomized, double blind, 2x2 factorial, placebo-controlled trial to prevent prostate cancer. 200 μg/day from L-selenomethionine and/or vitamin E at 400 IU/day of all rac α-tocopheryl acetate 32,400 healthy men, 2001-2004 After 7 years (5.5 on agents), there were 17 percent more cases of prostate cancer in men taking only vitamin E than in men taking only placebos. Quote: the study failed 6
The Monday morning quarterback. did not consider preclinical studies. preclinical studies did not exist. the epidemiology was weak. the wrong form of selenium or vitamin E. the wrong dose. etc. We do not learn from experience, we learn from reflecting upon experience. John Dewey? 7
A,B,C and Ds of a Diet/Nutrition Clinical Trial on Mechanisms Agents Biomarkers Cohort Dollars 8
Agent Considerations Pure Chemical / Pharmacologic model. Nutrient or non-nutrient dietary compound Form, safety, dose response, placebo possible. Food / Functional Foods Variation due to source, cultivar, season, growing conditions, soil, processing, cooking, stability over time. Placebo and double blinding may be problematic Dietary Patterns Heterogeneity among participants, compliance Control group is problematic. 9
Biomarkers Exposure Validated analytic technology. Dose response (linear, nonlinear) Bio accessibility. Pharmacokinetic / pharmacodynamic modeling. Context (meal and composition). Efficacy Surrogate endpoints (polyps, intraepithelial neoplasia) Mechanisms -omics, (mirna, mrna, proteins, epigenetics, genomics, metbolomics) Targeted approach. Hallmarks of Cancer 10
Cohorts Broad and generalizable / public health model Focused and personalized / medical model Host Genetics Carcinogen exposure (tobacco) Premalignancy (dysplasia, CIS, polyps) Nutritional criteria (deficiency) Infection (HepB, HPV) Immune suppressed (post-organ transplant) Cancer (recurrence of primary) Genomic signature Histopathology subtype 11
Dollars Budgets begin in US Congress. Clinical research is expensive. Arbitrary cuts compromise studies Statistical power Dose response Reduction of outcomes measured. Disproportionate funding for therapy of advanced Ca. Privatization of cancer research. Human Cancer Genome Atlas, etc. Molecular targeting is the current theme. Complexity is enormous, evolution of resistance common. High cost to develop drugs for smaller populations. My conclusion: prevention is the goal! 12
Thank You