An observational study in Gastric Cancer, Colorectal Cancer and Breast Cancer, sponsored by Centro de Tratamiento e Investigación sobre Cáncer, Luis Carlos Sarmiento Angulo. Recruiting at 1 site in Colombia. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-07-07.
Sponsored by Centro de Tratamiento e Investigación sobre Cáncer, Luis Carlos Sarmiento Angulo · Observational
This is a prospective observational cohort study conducted at Fundación CTIC in Bogotá, Colombia. It characterizes the oral, fecal and intratumoral microbiome of Colombian adults with advanced solid tumors (gastric, colorectal, breast, cervical and head-and-neck cancer) who receive first-line immunotherapy as standard of care, and compares them with healthy volunteers. Using multi-omics (HiFi metagenomics, 16S, tumor RNA-Seq and untargeted metabolomics), the study aims to identify microbial signatures associated with treatment response and survival, building the initial Colombian cohort of a Cancer Microbiome Atlas with Latin American projection.
Single-center, prospective, observational cohort study. 120 patients with advanced (stage III unresectable or IV) solid tumors candidates for first-line immunotherapy and 30 healthy controls are enrolled (total N=150). Patients provide saliva, stool and tongue-scraping samples plus archival FFPE tumor tissue at baseline (V0) and at 6 (V1) and 12 (V2) months; controls provide saliva and stool at V0 only. Microbiomes are profiled by PacBio HiFi shotgun metagenomics and full-length 16S; tumor transcriptome by RNA-Seq; and saliva/stool metabolome by GC-MS in a subcohort (n=60). Tumor response is assessed by RECIST 1.1. Microbial, transcriptomic and metabolomic features are integrated with clinical outcomes (objective response, PFS, OS) using multivariable and machine-learning models.
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This study's planned enrollment of 150 is below the median of 278 across 790 observational studies indexed under Stomach Neoplasms.
Browse Stomach Neoplasms studies →Centro de Tratamiento e Investigación sobre Cáncer, Luis Carlos Sarmiento Angulo is the lead sponsor of 5 studies on the registry; 5 are open to participants now.
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Colombian adults with advanced solid tumors (gastric, colorectal, breast, cervical, head-and-neck) candidates for first-line immunotherapy, plus healthy adult volunteers. Single center: Fundación CTIC, Bogotá.
Inclusion Criteria:
Inclusion Criteria (healthy controls)
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
A line of therapy is one course of treatment, which may combine several drugs. First-line is the first course given; second-line follows when that stops working or is not tolerated.
“Two prior lines” means two courses that count separately under the study’s rules — not simply two drugs. Ask the study team if you are unsure how yours are counted.
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Histologically or cytologically confirmed
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Line of therapy
A line of therapy is one course of treatment, which may combine several drugs. First-line is the first course given; second-line follows when that stops working or is not tolerated.
“Two prior lines” means two courses that count separately under the study’s rules — not simply two drugs. Ask the study team if you are unsure how yours are counted.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECOG performance status
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HbA1c
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
120 Colombian adults with advanced (stage III unresectable or IV) gastric, colorectal, breast, cervical or head-and-neck cancer, candidates for first-line immunotherapy (standard of care). Saliva, stool and tongue scraping collected at V0, V1 (6 mo) and V2 (12 mo); archival FFPE tumor block retrieved at V0.
Drug: First-line immunotherapy (immune checkpoint inhibitors), INVIMA-approved, standard of care
30 healthy adult volunteers without prior cancer, active autoimmune disease or inflammatory bowel disease, and without antibiotics or invasive dental treatment in the prior 3 months. Saliva and stool collected at V0 only; no longitudinal follow-up.
Exposure observed: first-line immunotherapy with immune checkpoint inhibitors administered as standard of care (INVIMA-approved); no experimental intervention is assigned by the study. Healthy controls receive no immunotherapy.
Oral, fecal and intratumoral microbiome signatures associated with objective tumor response (RECIST 1.1) to first-line immunotherapy
Characterization of oral, fecal and intratumoral microbiomes and identification of taxa and diversity metrics differentiating responders (CR+PR) from non-responders (SD+PD) by RECIST 1.1.
Time frame: Baseline (V0) and through 12 months
Differences in microbiome composition and diversity between cancer patients and healthy controls
Comparison of alpha and beta diversity and differential taxonomic and functional abundance between cancer patients and healthy controls.
Time frame: Baseline (V0)
Microbial, transcriptomic and metabolomic biomarkers associated with progression-free survival (PFS)
Up to 36 months
Time frame: Association of microbial diversity, key taxa, MAGs and functional pathways with progression-free survival, estimated by Kaplan-Meier and adjusted Cox models.
Microbial biomarkers associated with overall survival (OS)
Association of microbiome features with overall survival, estimated by Kaplan-Meier and adjusted Cox models.
Time frame: Up to 36 months
Tumor transcriptomic profile and gene-expression pathways modulated by the intratumoral microbiome
RNA-Seq characterization of tumor gene-expression and identification of pathways correlated with intratumoral microbiome composition.
Time frame: Baseline (V0)
Untargeted salivary and fecal metabolomic profile (subcohort, n=60)
GC-MS untargeted metabolomics of saliva and stool in a stratified subcohort (50 patients, 10 controls) to identify metabolites associated with microbiome composition and immunotherapy response.
Time frame: Baseline through 12 months
Plan to share: Yes — De-identified genomic sequences (oral, fecal and intratumoral microbiome) will be deposited in public repositories (NCBI SRA / EBI ENA) with minimal metadata (tumor type, age by decade, sex). Analysis pipelines and code will be versioned and shared via GitHub and Zenodo. Raw data and code will be made public at study close.
Supporting information: Study protocol, Statistical analysis plan, Analytic code
Time frame: Available at study close (estimated 2029); retained at least 15 years per ICH-GCP archiving policy.
Access criteria: Open access via public repositories (SRA, ENA, Zenodo) for de-identified sequence data and analysis code.
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Centro de Tratamiento e Investigación sobre Cáncer, Luis Carlos Sarmiento Angulo