Colorectal Cancer (CRC)CARE-CRCNCT06734156
CARE-CRC: Microbiome Insights and Correlations for Risk and Outcomes in Colorectal Cancer
An observational study of Colorectal Cancer (CRC) and Microbiome, run by Gulbenkian Institute for Molecular Medicine at 2 sites in Portugal.
Trial summary
Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths globally, with increasing incidence rates. While predominantly affecting older adults, CRC cases among individuals under 50 (early-onset CRC, or EoCRC) are rising. Read more about this study
- Who is it for?
- Ages 40 to 74 years
- Conditions the study is for
- Colorectal Cancer (CRC), Microbiome, Early Onset Colorectal Cancer
- How many people
- 400 participants
- Where
- 2 sitesPortugal
- Study dates
- 2 Mar 2026to 2 Dec 2029
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 40 to 74 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: The recruitment for this study will be conducted in close collaboration with the oncology and general surgery departments from partner hospitals. Participants who meet all eligible criteria will be selected and provided with detailed information about the clinical study by study coordinators at each hospital. Those who agree to participate will be required to sign an informed consent form.
Who may be able to join
- Be willing and able to provide written informed consent
- Resident in Portugal
- Age from 40 to 74 years
- Have a recent diagnosis of CRC without initiating any treatment.
Who cannot join
- Age < 40 years or ≥ 75 years
- Unable to provide informed consent
- Refusal to provide stool samples
- Previous or current treatment for CRC
- First-degree family history of CRC
- Previous diagnosis of inflammatory bowel disease (ulcerative colitis, Crohn's disease or indeterminate colitis), inflammatory bowel syndrome, recurrent infection by Clostridioides difficile
- Pregnancy
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Portugal2 sites, 2 recruiting
- Recruiting
Champalimaud Foundation
Lisbon, Lisbon District, 1400-038
José Azevedo, 210480200, jose.azevedo@fundacaochampalimaud.pt
José Azevedo, MD
- Recruiting
Gulbenkian Institute for Molecular Medicine
Lisbon, Lisbon District, 1649-028
Madalena Reis, +351 217999411, madalena.reis@gimm.pt
Ana S Almeida, PhD, +351 217999411, ana.almeida@gimm.pt
About this study
Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths globally, with increasing incidence rates. While predominantly affecting older adults, CRC cases among individuals under 50 (early-onset CRC, or EoCRC) are rising. This age group rarely undergoes routine screening, resulting in delayed diagnoses and more advanced disease at presentation. In the USA, EoCRC accounts for 10% of CRC cases and is the leading cause of cancer-related deaths in men under 50.
Despite the increase in EoCRC incidence, the causes remain unclear. Only 25% of cases have a CRC family history, suggesting environmental factors. Diets low in fibre and rich in fat and red meat, obesity, alcohol consumption, sedentary lifestyle, stress, and chronic inflammation of the GI tract are estimated to account for 70-90% of CRC risk. According to the World Cancer Research Fund, 47% of all CRC cases could be prevented through lifestyle changes, particularly in diet and physical activity.
Read more
These lifestyle factors are also strongly linked to changes in the gut microbiome, which differs markedly between CRC patients and healthy individuals. The microbiome may influence tumour development by producing metabolites that regulate immune responses or create anti-tumour environments. Thus, the gut microbiome is a promising target for early CRC detection and prevention.
This study aims to develop a non-invasive, microbiome-based diagnostic tool for CRC, identifying biomarkers to improve early detection, personalise treatment, and reduce healthcare costs.
Read the detailed description
This study focuses on identifying faecal microbiome biomarkers for CRC across different stages, prognoses, and therapeutic responses, with a particular emphasis on EoCRC. Recruitment will include individuals recently diagnosed with CRC who have not undergone treatment.
Faecal samples will be collected at three key time points:
Baseline - At diagnosis and study entry. Post-Treatment - After completing each therapeutic regimen, such as neoadjuvant chemotherapy, surgery and/or adjuvant chemotherapy Follow-Up - Three years after diagnosis. The study will also monitor survival rates and disease progression over three years.
Primary Objective:
To identify and characterise changes in the gut microbiome at different CRC stages.
Secondary Objectives:
- Identify faecal microbiome biomarkers associated with CRC overall and stratify findings by age and sex. ii. Compare microbiome profiles and associated clinical and lifestyle data between CRC patients and healthy controls, stratified by age and sex. iii. Identify lifestyle and dietary factors contributing to CRC risk, stratified by age and sex. iv. Validate biomarkers specific to EoCRC. v. Correlate microbiota composition with overall survival. vi. Correlate microbiota composition with disease-free survival.
This is a longitudinal observational study targeting individuals aged 40-74 who have been newly diagnosed with CRC and are treatment-naïve
Patients with all inclusion criteria and none of the exclusion criteria (detailed in the specific section of this website) will be considered for this study. Using a significance level of 5% and a power of 80%, the required sample size is 80 individuals per age group (40-49, 50-59, 60-64, 65-69, and 70-74 years). This results in a total of 400 participants. A control group of healthy individuals will be recruited from hospital patients undergoing routine screening colonoscopies.
Biological and clinical data will be collected at multiple time points throughout the study. Faecal samples will be obtained at baseline, post-treatment, and during the three-year follow-up, accompanied by blood sample collection at each of these time points. Clinical data will include detailed tumour characteristics, such as location, symptoms, and staging, as well as treatment information, including surgery and chemotherapy. Outcomes related to survival and disease progression will also be recorded.
Lifestyle and dietary data will be gathered through self-reported questionnaires capturing demographic factors such as age, smoking habits, physical activity, stress levels, and body mass index (BMI). Dietary habits and adherence to the Mediterranean diet will be assessed via telephone interviews.
The gut microbiome will be profiled using shotgun metagenomic sequencing, enabling the characterisation of microbial species and functional pathways. This analysis will identify potential correlations between microbiome composition and clinical outcomes, including therapeutic responses and survival rates.
For statistical testing, qualitative variables will be analysed using Chi-square or Fisher's exact tests, while quantitative variables will be assessed using Student's t-test or ANOVA. If the normality assumption is not met, Mann-Whitney or Kruskal-Wallis tests will be used. All statistical analyses will be two-sided, with a significance level set at 5%.
Expected Outcomes:
The study aims to identify biomarkers that enable early, non-invasive CRC detection. Findings will also provide insights into the interplay between lifestyle, diet, and microbiome changes in CRC progression. These insights could lead to personalised preventive strategies and improved therapeutic outcomes.
- Being tested
- No intervention: observational study
- Keywords
- Colorectal Cancer, Gut Microbiota, Microbiome, Early-onset Colorectal Cancer, Biomarkers, Diet, Risk factors, Metagenomics
- Medical subject headings
- Colorectal Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
No intervention: observational studyOther
No intervention: observational study
| Study group | Role | What they receive |
|---|---|---|
| Colorectal Cancer (CRC) | Participants with a confirmed CRC diagnosis, stratified by age: 40-49, 50-59, 60-64, 65-69, and 70-74 years. Receives: Other: No intervention: observational study |
What is being measured
The primary outcome is the main question the study is designed to answer.
Microbiome biomarkers associated with CRC.
The faecal microbiome's composition and gene profiles will be analysed using shotgun metagenomic sequencing. Data will be integrated with lifestyle and dietary factors to identify biomarkers linked to CRC stages.
Measured: Baseline and Follow-up up to 3 years
Microbiome biomarkers associated with EoCRC.
Similar analysis as Outcome number 1, focused specifically on early-onset CRC cases.
Measured: Baseline and Follow-up up to 3 years
Correlation between microbiome biomarkers and overall survival and disease-free survival.
Biomarkers will be correlated with clinical follow-up data, including overall survival (survivors vs non-survivors) and disease-free progression (relapse vs no relapse).
Measured: 3 years
Secondary outcomes (7)
Effect of diet on CRC risk and gut microbiota composition
Dietary intake will be assessed via telephone interviews using two 24-hour dietary recalls. These follow protocols validated by the European Food Safety Authority (EFSA) and the Portuguese National Food and Physical Activity Survey (IAN-AF).
Measured: Baseline
Effect of the Mediterranean Diet (MD) on CRC risk and gut microbiota composition
Adherence to the MD will be assessed with the PREvención con DIeta MEDiterránea (PREDIMED) questionnaire, a validated 14-item tool. Scores (0-14) will categorise adherence as low (<5), moderate (6-9), or high (>10).
Measured: Baseline
Effect of physical activity on CRC risk and gut microbiota composition
Physical activity will be assessed using the Nordic Physical Activity Questionnaire-Short (NAPQ-short) form, which evaluates adherence to WHO physical activity recommendations.
Measured: Baseline
Effect of sleeping habits on CRC risk and gut microbiota composition
Sleeping habits will be assessed by the Pittsburgh Sleep Quality Index, a validated questionnaire that consists of 19 items which are distributed into seven "components": subjective sleep quality; sleep latency; sleep duration; habitual sleep efficiency; sleep disturbances; use of sleeping medication; day-time dysfunction. Each component is scored from 0 to 2, and the sum of the component scores yields a global PSQI score. A global PSQI score of ≥6 will indicate poor sleep quality.
Measured: Baseline
Effect of stress levels on CRC risk and gut microbiota composition
Stress levels will be evaluated using the Perceived Stress Scale (PSS), a validated 10-item tool. Scores range from 0-40, categorised as low (0-13), moderate (14-26), or high (27-40).
Measured: Baseline
Identify and quantity inflammation markers
Blood samples will be collected in K2EDTA tubes and processed for plasma separation. Inflammatory markers, including C-reactive protein and cytokines (e.g., IL-1β, IL-6, TNF-α), will be quantified using ELISA.
Measured: Baseline and Follow-up up to 3 years
Differential gene expression in tumour samples
For participants undergoing surgery, tumour samples will be collected, preserved, and processed for transcriptomic analysis. RNA extraction will be performed to assess gene expression profiles, with a particular focus on microsatellite instability (MSI) and tumour microenvironment interactions.
Measured: Baseline
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Dec 2024
- Study start2 Mar 2026
- Primary completion2 Dec 2026 (estimated)
- Study completion2 Dec 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Colorectal Cancer (CRC)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 400 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Gulbenkian Institute for Molecular Medicine
- Sponsor type
- University, hospital or other
- Collaborators
- Fundacao Champalimaud, Centro Hospitalar Lisboa Norte
- Responsible party
- Sponsor
- Investigators
- Ana S Almeida, PhD, Principal investigator, Gulbenkian Institute for Molecular Medicine
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06734156
- Sponsor's protocol ID
- CAML Ref nº 265/24
- Other IDs
- 101060102
- Acronym
- CARE-CRC
- Status last verified
- May 2026
- First submitted
- 11 Dec 2024
- Last updated
- 12 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 12 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- CARE-CRC: Microbiome Insights and Correlations for Risk and Outcomes in Colorectal Cancer
- ClinicalTrials.gov ID
- NCT06734156
- Acronym / sponsor ID
- CARE-CRC / CAML Ref nº 265/24
- Keywords
- Colorectal Cancer, Gut Microbiota, Microbiome, Early-onset Colorectal Cancer, Biomarkers, Diet, Risk factors, Metagenomics
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 400 participants (estimated)
- Lead sponsor
- Gulbenkian Institute for Molecular MedicineUniversity, hospital or other
- Collaborators
- Fundacao Champalimaud, Centro Hospitalar Lisboa Norte
- Study start
- 2 Mar 2026 (actual)
- Primary completion
- 2 Dec 2026 (estimated)
- Study completion
- 2 Dec 2029 (estimated)
- First posted
- 16 Dec 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths globally, with increasing incidence rates. While predominantly affecting older adults, CRC cases among individuals under 50 (early-onset CRC, or EoCRC) are rising. This age group rarely undergoes routine screening, resulting in delayed diagnoses and more advanced disease at presentation. In the USA, EoCRC accounts for 10% of CRC cases and is the leading cause of cancer-related deaths in men under 50.
Despite the increase in EoCRC incidence, the causes remain unclear. Only 25% of cases have a CRC family history, suggesting environmental factors. Diets low in fibre and rich in fat and red meat, obesity, alcohol consumption, sedentary lifestyle, stress, and chronic inflammation of the GI tract are estimated to account for 70-90% of CRC risk. According to the World Cancer Research Fund, 47% of all CRC cases could be prevented through lifestyle changes, particularly in diet and physical activity.
These lifestyle factors are also strongly linked to changes in the gut microbiome, which differs markedly between CRC patients and healthy individuals. The microbiome may influence tumour development by producing metabolites that regulate immune responses or create anti-tumour environments. Thus, the gut microbiome is a promising target for early CRC detection and prevention.
This study aims to develop a non-invasive, microbiome-based diagnostic tool for CRC, identifying biomarkers to improve early detection, personalise treatment, and reduce healthcare costs.
Detailed description
This study focuses on identifying faecal microbiome biomarkers for CRC across different stages, prognoses, and therapeutic responses, with a particular emphasis on EoCRC. Recruitment will include individuals recently diagnosed with CRC who have not undergone treatment.
Faecal samples will be collected at three key time points:
Baseline - At diagnosis and study entry. Post-Treatment - After completing each therapeutic regimen, such as neoadjuvant chemotherapy, surgery and/or adjuvant chemotherapy Follow-Up - Three years after diagnosis. The study will also monitor survival rates and disease progression over three years.
Primary Objective:
To identify and characterise changes in the gut microbiome at different CRC stages.
Secondary Objectives:
- Identify faecal microbiome biomarkers associated with CRC overall and stratify findings by age and sex. ii. Compare microbiome profiles and associated clinical and lifestyle data between CRC patients and healthy controls, stratified by age and sex. iii. Identify lifestyle and dietary factors contributing to CRC risk, stratified by age and sex. iv. Validate biomarkers specific to EoCRC. v. Correlate microbiota composition with overall survival. vi. Correlate microbiota composition with disease-free survival.
This is a longitudinal observational study targeting individuals aged 40-74 who have been newly diagnosed with CRC and are treatment-naïve
Patients with all inclusion criteria and none of the exclusion criteria (detailed in the specific section of this website) will be considered for this study. Using a significance level of 5% and a power of 80%, the required sample size is 80 individuals per age group (40-49, 50-59, 60-64, 65-69, and 70-74 years). This results in a total of 400 participants. A control group of healthy individuals will be recruited from hospital patients undergoing routine screening colonoscopies.
Biological and clinical data will be collected at multiple time points throughout the study. Faecal samples will be obtained at baseline, post-treatment, and during the three-year follow-up, accompanied by blood sample collection at each of these time points. Clinical data will include detailed tumour characteristics, such as location, symptoms, and staging, as well as treatment information, including surgery and chemotherapy. Outcomes related to survival and disease progression will also be recorded.
Lifestyle and dietary data will be gathered through self-reported questionnaires capturing demographic factors such as age, smoking habits, physical activity, stress levels, and body mass index (BMI). Dietary habits and adherence to the Mediterranean diet will be assessed via telephone interviews.
The gut microbiome will be profiled using shotgun metagenomic sequencing, enabling the characterisation of microbial species and functional pathways. This analysis will identify potential correlations between microbiome composition and clinical outcomes, including therapeutic responses and survival rates.
For statistical testing, qualitative variables will be analysed using Chi-square or Fisher's exact tests, while quantitative variables will be assessed using Student's t-test or ANOVA. If the normality assumption is not met, Mann-Whitney or Kruskal-Wallis tests will be used. All statistical analyses will be two-sided, with a significance level set at 5%.
Expected Outcomes:
The study aims to identify biomarkers that enable early, non-invasive CRC detection. Findings will also provide insights into the interplay between lifestyle, diet, and microbiome changes in CRC progression. These insights could lead to personalised preventive strategies and improved therapeutic outcomes.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Colorectal Cancer (CRC) | – | Other: No intervention: observational studyParticipants with a confirmed CRC diagnosis, stratified by age: 40-49, 50-59, 60-64, 65-69, and 70-74 years. |
Who may qualify
- Ages
- 40 to 74 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- The recruitment for this study will be conducted in close collaboration with the oncology and general surgery departments from partner hospitals. Participants who meet all eligible criteria will be selected and provided with detailed information about the clinical study by study coordinators at each hospital. Those who agree to participate will be required to sign an informed consent form.
Key inclusion criteria (4 listed)
- Be willing and able to provide written informed consent
- Resident in Portugal
- Age from 40 to 74 years
- Have a recent diagnosis of CRC without initiating any treatment.
Key exclusion criteria (7 listed)
- Age < 40 years or ≥ 75 years
- Unable to provide informed consent
- Refusal to provide stool samples
- Previous or current treatment for CRC
- First-degree family history of CRC
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| No intervention: observational studyNo intervention: observational study | Other | Colorectal Cancer (CRC) |
Primary outcome
Microbiome biomarkers associated with CRC.
Time frame: Baseline and Follow-up up to 3 years
The faecal microbiome's composition and gene profiles will be analysed using shotgun metagenomic sequencing. Data will be integrated with lifestyle and dietary factors to identify biomarkers linked to CRC stages.
Microbiome biomarkers associated with EoCRC.
Time frame: Baseline and Follow-up up to 3 years
Similar analysis as Outcome number 1, focused specifically on early-onset CRC cases.
Correlation between microbiome biomarkers and overall survival and disease-free survival.
Time frame: 3 years
Biomarkers will be correlated with clinical follow-up data, including overall survival (survivors vs non-survivors) and disease-free progression (relapse vs no relapse).
7 secondary outcomes
Effect of diet on CRC risk and gut microbiota composition
Time frame: Baseline
Effect of the Mediterranean Diet (MD) on CRC risk and gut microbiota composition
Time frame: Baseline
Effect of physical activity on CRC risk and gut microbiota composition
Time frame: Baseline
Effect of sleeping habits on CRC risk and gut microbiota composition
Time frame: Baseline
Effect of stress levels on CRC risk and gut microbiota composition
Time frame: Baseline
Identify and quantity inflammation markers
Time frame: Baseline and Follow-up up to 3 years
Differential gene expression in tumour samples
Time frame: Baseline
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 12 May 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Ana S Almeida, PhD principal investigator
Gulbenkian Institute for Molecular Medicine
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Colorectal Cancer (CRC) and Microbiome, run by Gulbenkian Institute for Molecular Medicine at 2 sites in Portugal.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 12 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Portugal. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Ana S Almeida, PhD (+351 217999411, ana.almeida@gimm.pt), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Microbiome biomarkers associated with CRC. (time frame: Baseline and Follow-up up to 3 years). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 12 May 2026.