Zell JA, McLaren CE, Morgan TR, et al. - Whether colorectal tissue S6^Ser235 among obese patients with recent history of colorectal adenoma (CRA) would be influenced by metformin, was determined in this phase IIa clinical biomarker trial including nondiabetic, obese people (BMI ≥ 30) with ages 35 to 80 and a recent history of CRA. This inquiry was performed via the U.S. National Cancer Institute-Chemoprevention Consortium. Researchers administered participants oral metformin 1,000 mg twice every day for 12 weeks. They collected rectal mucosa biopsies at baseline and end-of-treatment (EOT) endoscopy. They found no significant differences when compared EOT with baseline tissue S6^Ser235 by IHC. At baseline and at EOT, mean (SD) Histo score (Hscore) was 1.1 (0.57) and 1.1 (0.51), respectively; median Hscore change was 0.034. Adverse events consistent with metformin's recognized side-effect profile were documented. No decrease in rectal mucosa pS6 or Ki-67 levels was brought about by 12 weeks of oral metformin in obese patients with CRA.