Modulating gut bacteria with antibiotics for rectal cancer treatment

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This phase 2 clinical trial aims to enhance the treatment response in patients with locally advanced rectal adenocarcinoma by using metronidazole to modulate the intestinal microbiome during neoadjuvant radiotherapy. Participants will receive a daily dose of 1,500 mg of metronidazole for the first seven days of treatment, with adherence monitored through patient records and consultations. The study will evaluate the effectiveness of this intervention by comparing outcomes to historical controls, focusing on the rate of complete pathological response and changes in the intestinal bacterial profile. Adverse effects will be closely monitored to ensure patient safety.

Why it matters

Who can join: the full rules

Inclusion Criteria:

* Patients over 18 years old with middle and lower rectal adenocarcinoma, classified as locally advanced or where the tumor´s location necessitates rectal amputation surgery;
* Tumors located below the peritoneal reflection, as determined by MRI, will be defined as middle and lower rectum;
* Patients eligible for rectal amputation will be those with tumor whose distal margin is less than 2,0cm from the pectineal line, as determined by rectoscopy, or less than 2,0cm from the anorectal ring by palpation or MRI.
* Patients with middle rectum cancer candidates for radiotherapy as part of neoadjuvant treatment will be included according to the following criteria: mesorectal fascia compromised by direct extension of the primary tumor or by an affected lymph node; cT4 tumors.

Exclusion Criteria:

* Patients without performance status for total neoadjuvant treatment;
* Histologies other than adenocarcinoma;
* Adenocarcinomas with a microsatellite instability phenotype, as determined by immunohistochemistry;
* Patients with middle rectal tumors who are not indicated for radiotherapy in the neoadjuvant treatment regimen, according to the institutional protocol (tumors cT3N0, with free mesorectal fascia; cT1-3 N+, with free mesorectal fascia).

Where it's running

• A.C Camargo Cancer Center
  São Paulo, São Paulo, Brazil Recruiting

Study contacts

• Principal investigator: Samuel Aguiar Jr, MD, PhD — A.C. Camargo Cancer Center
• Study coordinator: Samuel Aguiar Jr, MD, PhD
• Email: samuel.aguiar@accamargo.org.br
• Phone: + 55 (11) 2189-5010

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How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.