Conditions: Adenomatous Polyp Colorectal Cancer Obesity
Allocation: NA | Intervention model: SINGLE_GROUP
Enrollment: 45
Healthy volunteers: no

Brief summary:
The purpose of this study is to find out whether METFORMIN decreases protein markers in colorectal tissue. This is a phase IIA study of the pharmacodynamics, safety and tolerability of Metformin in decreasing colorectal mucosa in patients with a history of colorectal adenomas in the past 3 years and a BMI \>= 30, with decimals rounded to the nearest whole integer. Metformin as a potential chemopreventive agent for inhibition of the relevant molecular pathways involved in human colorectal carcinogenesis.

Detailed description:
PRIMARY OBJECTIVES:

I. To determine if a 12-week intervention of oral metformin (metformin hydrochloride) treatment among obese patients with a history of colorectal adenomas results in at least a 35% decrease in colorectal mucosa activated pS6serine235 from baseline as assessed via immunostaining.

SECONDARY OBJECTIVES:

I. To assess the effect of metformin on additional relevant biomarkers in serum: metformin levels; fasting insulin-like growth factor (IGF)-1, insulin-like growth factor binding protein (IGFBP)-1, IGFBP-3; fasting leptin; fasting Adiponectin; fasting and 2 hour post-prandial insulin and glucose.

II. To examine the correlation among biomarkers (serum, tissue). III. To assess the independent effects of treatment on each biomarker, using multivariate regression models to account for clinical and biomarker data.

IV. To document the safety and tolerability of metformin in the study population.

TERTIARY OBJECTIVES:

I. To assess the effect of metformin on additional relevant biomarkers in tissue via immunostaining. This will include the effects on levels of colorectal mucosa proliferation estimated by: phosphorylated AMPK (pAMPK), phosphorylated AKTserine 473 (pAKT), phosphorylated mTOR, phosphorylated insulin receptor (pIR), phosphorylated IGF-1 (pIGF-1) receptor, and Ki-67.

II. To cross-validate immunostaining results with Western blotting experiments in a subset of consecutive patients for the following endpoints: phosphorylated S6serine235 (pS6serine235), phosphorylated AMPK (pAMPK), phosphorylated AKTserine 473 (pAKT), phosphorylated mTOR, phosphorylated insulin receptor (pIR), phosphorylated IGF-1 (pIGF-1) receptor, and Ki-67.

OUTLINE:

Patients receive metformin hydrochloride orally (PO) once daily (QD) during week 1 and then twice daily (BID) during weeks 2-12. Treatment continues for 12 weeks in the absence of disease progression or unacceptable toxicity.

After completion of study therapy, patients are followed up for 4 weeks.

Arms:
arm 1: Patients receive metformin hydrochloride PO QD during week 1 and then BID during weeks 2-12. Treatment continues for 12 weeks in the absence of disease progression or unacceptable toxicity.

Interventions: intervention 1: metformin hydrochloride
Intervention descriptions: intervention 1: None

Protocol document: