Impact of Fusobacterium Nucleatum on Response to Anti-EGFR Therapy in Metastatic Colorectal Cancer

NCT07619859 | Active Not Recruiting

• 1 other identifier: CAAE 72877217.8.0000.5437
• Study Type: observational
• Target: 500
• Locations: 1 country
• Sites: 1

Brief Summary

This retrospective observational cohort study investigates the association between the intratumoral burden of the bacterium Fusobacterium nucleatum (Fn) and the efficacy of anti-EGFR targeted therapies (cetuximab or panitumumab) in patients with RAS wild-type metastatic colorectal cancer (mCRC). Bacterial quantification will be performed using droplet digital polymerase chain reaction (ddPCR) on formalin-fixed, paraffin-embedded (FFPE) tissue samples, comprising an estimated cohort of 500 patients.

Conditions

Metastatic Colorectal Cancer (CRC)

Outcome Measures

Primary Outcomes (3)

• Objective Response Rate (ORR)

  Proportion of patients who achieved complete or partial response as assessed according to standardized RECIST 1.1 criteria.

  From the date of first anti-EGFR administration until disease progression, assessed up to 186 months

• Overall Survival (OS)

  Time elapsed from diagnosis to death from any cause

  From the date of initial anti-EGFR therapy administration to the date of death from any cause, with a maximum follow-up assessment of up to 186 months.

• Progression-Free Survival (PFS).

  Time elapsed from treatment initiation (for each line of therapy) to radiological disease progression or death.

  From the date of initial anti-EGFR therapy administration to the date of first documented radiological disease progression, with a maximum follow-up assessment of up to 186 months

Secondary Outcomes (5)

• F. nucleatum Load by Tumor Topography and Paired Metastases, Assessed by ddPCR

  Up to 186 months.

• Survival Outcomes by Treatment Line (Kaplan-Meier)

  From the date of initial anti-EGFR therapy administration, with a maximum follow-up assessment of up to 186 months

• OS and PFS Stratified by Age (Kaplan-Meier Method)

  From the date of initial anti-EGFR therapy administration, with a maximum follow-up assessment of up to 186 months

• OS and PFS Stratified by Antibiotic Use (Kaplan-Meier Method)

  "From the date of initial anti-EGFR therapy administration, with a maximum follow-up assessment of up to 186 months

• F. nucleatum Load by Tumor Mutational Profile, Assessed by ddPCR

  Up to 186 months

Study Arms (2)

Cohort 1 - High Fn

Patients with intratumoral Fusobacterium nucleatum burden above the median.

Cohort 2 - Low/Negative Fn

Patients with intratumoral Fusobacterium nucleatum burden less than or equal to the median, or with undetectable infection

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

The study population consists of patients diagnosed with metastatic (Stage IV) colorectal adenocarcinoma who received at least one cycle of anti-EGFR therapy (Cetuximab or Panitumumab) between January 2016 and December 2022 at the Hospital de Amor (Barretos, SP, Brazil). Eligible patients must have formalin-fixed paraffin-embedded (FFPE) tumor tissue samples available in the institutional biobank for molecular analysis. Patients with primary tumors outside the colon or rectum, non-adenocarcinoma histology, or with activating mutations in KRAS, NRAS, or BRAF (unless anti-EGFR was used in combination with BRAF inhibitors) are excluded.

You may qualify if:

• Histologically confirmed diagnosis of metastatic (Stage IV) adenocarcinoma of the colon or rectum.
• Received at least one cycle of anti-EGFR therapy (cetuximab or panitumumab), either as monotherapy or in combination regimens, regardless of the line of therapy.
• Anti-EGFR therapy administered between January 2016 and December 2022.
• Availability of formalin-fixed paraffin-embedded (FFPE) tumor tissue blocks (from primary tumor or metastatic site) stored in the institutional biobank, with adequate quality for molecular analysis

You may not qualify if:

• Primary tumor originating in sites other than the colon or rectum.
• Presence of activating mutations in KRAS or NRAS genes.
• Presence of BRAF gene mutation (except for patients who received anti-EGFR therapy combined with BRAF inhibitors, according to standard clinical practice for this subgroup).
• Tumor histology other than adenocarcinoma.
• Insufficient clinical or follow-up data in medical records for the evaluation of the study's primary endpoints

Sponsors & Collaborators

• Barretos Cancer Hospital: lead

Study Sites (1)

Barretos Cancer Hospital

Barretos, São Paulo, 14784-400, Brazil

Location

MeSH Terms

Conditions

Colorectal Neoplasms

Condition Hierarchy (Ancestors)

Intestinal Neoplasms; Gastrointestinal Neoplasms; Digestive System Neoplasms; Neoplasms by Site; Neoplasms; Digestive System Diseases; Gastrointestinal Diseases; Colonic Diseases; Intestinal Diseases; Rectal Diseases

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: RETROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: May 7, 2026
• First Posted: June 2, 2026
• Study Start: July 5, 2024
• Primary Completion (Estimated): December 10, 2027
• Study Completion (Estimated): June 1, 2028
• Last Updated: June 4, 2026

Record last verified: 2026-05

Locations

BR (1)