Using metronidazole before surgery for colorectal cancer

Preoperative Treatment With Metronidazole to Evaluate the Efficacy in Reducing Fusobacterium Nucleatum Tumor Colonization in Patients With Colorectal Cancer (CRC): a Proof-of-concept Trial

Phase 2 Interventional Oncology Institute of Southern Switzerland · NCT05748145

This study tests if giving metronidazole before surgery can help reduce a specific bacteria in colorectal cancer patients and possibly improve their treatment outcomes.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment40 (estimated)
Ages18 Years and up
SexAll
SponsorOncology Institute of Southern Switzerland Academic / other
Drugs / interventionschemotherapy
Locations1 site (Bellinzona, Canton Ticino)
Trial IDNCT05748145 on ClinicalTrials.gov

What this trial studies

This clinical trial aims to evaluate the effectiveness of metronidazole in reducing the presence of Fusobacterium nucleatum in colorectal cancer tissues. The study focuses on patients with untreated, primary colorectal adenocarcinoma who are candidates for surgical resection. By administering metronidazole prior to surgery, the trial seeks to determine its impact on tumor growth and the tumor microenvironment. The research is based on previous findings that suggest Fusobacterium nucleatum may contribute to chemotherapy resistance and poor patient outcomes.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18 and older with untreated, primary colorectal adenocarcinoma located more than 15 cm from the anal verge.

Not a fit: Patients with a history of hypersensitivity to metronidazole or those requiring emergency surgery within 14 days will not benefit from this study.

Why it matters

Potential benefit: If successful, this approach could improve surgical outcomes and overall survival rates for colorectal cancer patients.

How similar studies have performed: While the specific application of metronidazole in this context is novel, previous studies have indicated its effectiveness in reducing Fusobacterium nucleatum in animal models.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Written informed consent according to ICH/GCP regulations before registration.
* Age ≥ 18 years old
* Untreated, primary colorectal adenocarcinoma (\> 15 cm from the anal verge)
* Colonoscopy with endoscopic biopsy for disease confirmation and correlative studies.
* Candidates for surgical resection prior to administration of any therapy.

Exclusion Criteria:

* Insufficient material on the tissue biopsy to be left in the archives of the Cantonal Institute of Pathology for further evaluations/analyses
* Known prior history of hypersensitivity to metronidazole or other nitroimidazole derivatives
* Oral or parenteral antibiotic therapy within the six weeks prior to enrolment
* Emergency surgery (planned within less than 14 days), where no opportunity to administer preoperative oral antibiotics exists
* Other malignant disease within 5 years prior to study enrollment, except basocellular or squamous skin cancer and carcinoma in situ cervices uteri
* Any previous anticancer treatment prior resection
* Women who are pregnant or breast feeding
* Fertile women or men who do not use safe contraception during the study period
* Other clinically significant concomitant disease states (e.g., renal failure, hepatic dysfunction, cardiovascular disease, etc.),
* Inability to consent and follow the procedures of the study e.g. due to language problems, psychological disorders, dementia, etc. of the participant,
* Participation in another study with investigational drug within the 30 days preceding and during the present study,
* Any other serious underlying medical, psychiatric, psychological, familial or geographical condition, which in the judgment of the investigator may interfere with the planned staging, treatment, affect patient compliance or place the patient at high risk from treatment-related complications

Where this trial is running

Bellinzona, Canton Ticino

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Colorectal Cancer
Last reviewed 2026-06-09 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.