Abstract A26: Pilot trial to examine the effect of ginger on the gut microbiome: The Minnesota Cancer Clinical Trials Network

Experimental and epidemiologic evidence shows that the use of ginger root may reduce the incidence of colorectal cancer (CRC), but the mechanism through which ginger exerts its effect is unclear. Recently, an imbalanced gut microbiome was linked to inflammation, immune response, and CRC risk. Thus, we hypothesize that ginger intake may decrease CRC risk via changing the gut microbiome. The goals of this study are (1) assess whether ginger intake shifts the distribution of the gut microbiome from proinflammatory, CRC-predisposing bacteria and towards anti-inflammatory, CRC-protective bacteria and (2) evaluate the feasibility of conducting a large randomized clinical trial (RCT) leveraging the recently established Minnesota Cancer Clinical Trials Network (MNCCTN). We will conduct a pilot double-blind RCT, called “GINGER,” of 95-100 subjects aged 50-75 years old who were diagnosed with colorectal adenoma within the last 5 years (ClinicalTrials.gov NCT03268655). The subjects will be randomized to receive either 2,000 mg of ginger extract per day or matching placebo (1:1) for 6 weeks; the treatment phase will be followed by a 6-week washout. Fecal samples to characterize the gut microbiome will be collected at baseline, midpoint (week 6), and study end. Microbiome composition will be characterized by sequencing microbial 16S ribosomal RNA genes. In addition, pre- and postexposure urine samples will be collected to examine the correlation between bacteria and urinary metabolite of prostaglandin E2, which is an inflammatory biomarker and a putative biomarker for CRC. The methodology for “GINGER” was informed by an RCT recently completed by our group that involved aspirin as the intervention. In that RCT, which included 50 subjects and 5 stool collections within 12 weeks, 49 subjects completed the entire study and all stool collections. Adherence rates for the aspirin measured by pill count was at least 90%. Thus, these pilot data support the feasibility of the GINGER study. To implement the “GINGER,” we are using the resources of the MNCCTN, established in 2017. The MNCCTN, funded by Minnesota legislature and led by Masonic Cancer Center, University of Minnesota, will bring the “GINGER” and subsequent cancer clinical trials to communities throughout Minnesota, thus reducing the patients’ burden of travel and related costs. The network partners with Minnesota’s five largest health care providers (Essentia Health, Sanford Health, Mayo Clinic Cancer Center, Metro-Minnesota Community Oncology Research Consortium, and Fairview Health System) to provide infrastructure for conducting cancer trials at 18 sites outside the Twin-Cities metro area and Rochester, Minnesota. The “GINGER”—the first study conducted within the network—will begin recruitment in 3 sites by the end of November and in 6 sites by the end of 2018. Based on our previous experience, we expect to recruit 24-25 (25%) subjects in 3 months, 50%, in 6 months and all subjects by the end of 2019. Citation Format: Anna Prizment, Timothy R. Church, Dorothy Hatsukami, Robert Madoff, Christopher Staley, Robert J. Straka, Allison Iwan, Jenn Stromberg, Ya-Feng Wen, Cheryl Stibbe, Marie Rahne. Pilot trial to examine the effect of ginger on the gut microbiome: The Minnesota Cancer Clinical Trials Network [abstract]. In: Proceedings of the AACR Special Conference on Modernizing Population Sciences in the Digital Age; 2019 Feb 19-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(9 Suppl):Abstract nr A26.