Intestinal Microbiome Modulation With Antibiotics in the Neoadjuvant Treatment of Locally Advanced Rectal Cancer

Colorectal cancer is the second most common malignancy worldwide and one-third of these tumors are located in the rectum. The treatment may involve up to three modalities: radiotherapy, chemotherapy, and surgery. For several years, thanks mainly to Brazilian researchers, subgroups of patients have been selected for non-surgical treatment when chemoradiotherapy induces a complete clinical response. These treatment regimens have reached a plateau leading researchers to seek strategies that can increase response rates. Intestinal microbiota studies have shown that an overpopulation of certain anaerobic bacteria is generally associated with poorer treatment response. No study has attempted to intervene in the gut microbiota to increase the complete response rate in rectal cancer. The proposal of the investigators aims to modulate the intestinal microbiota through a phase 2 clinical trial, with the use of metronidazole as the intervention .

NCT Number	NCT06793137
Lead Sponsor	AC Camargo Cancer Center Collaborators: Conselho Nacional de Desenvolvimento Científico e Tecnológico
Conditions	Rectal Cancer, Adenocarcinoma
Enrollment	100 participants
Start Date	2024-07-22
Primary Completion	2025-10-31 (estimated)
Study Completion	2026-04-30 (estimated)
Updated on ClinicalTrials.gov	2025-01-29