Pathological Response to Perioperative FLOT in Gastric Adenocarcinoma

September 29, 2026 updated by: Henry Alexander Vargas Diaz, Fundación Santa Fe de Bogota

Evaluation of Pathological Response to the FLOT Regimen in the Perioperative Management of Gastric Adenocarcinoma

Perioperative chemotherapy with the FLOT regimen (5-fluorouracil, leucovorin, oxaliplatin and docetaxel) is a standard treatment for resectable gastric and gastroesophageal junction adenocarcinoma. However, real-world studies have reported lower pathological complete response rates than the pivotal trials, and Colombian evidence is limited, coming mainly from surgical series focused on operative outcomes.

This descriptive retrospective study will review the medical records of adults with stage I to III gastric or gastroesophageal junction adenocarcinoma who started perioperative FLOT at Fundación Santa Fe de Bogotá (Bogotá, Colombia) between January 1, 2021 and December 31, 2025 (approximately 90 patients). It will describe pathological response (tumor regression grade by the Mandard system and pathological complete response), grade 3-4 toxicity, dose modifications, treatment adherence and completion, recurrence and overall survival. The investigators will not assign or modify any treatment, and no hypothesis testing will be performed.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Background: Gastric cancer is the fifth most frequent cancer and the fourth leading cause of cancer death worldwide. In resectable disease, perioperative FLOT (four preoperative and four postoperative cycles) improved pathological regression and overall survival compared with epirubicin-based regimens in the FLOT4-AIO trial. Real-world series such as RealFLOT reported a lower pathological complete response rate (7.3%) than the pivotal trial, and a Colombian series reported 8.4%. There is no systematic institutional characterization of tolerance, pathological response, adherence and completion of perioperative FLOT in Colombia.

Design: Single-center, observational, descriptive, retrospective cohort (case series) study. All patients received the same regimen and there is no comparator group; the study has no hypothesis-testing purpose.

Population and identification: Adults older than 18 years with histologically confirmed stage I, II or III gastric or gastroesophageal junction adenocarcinoma who started perioperative FLOT at Fundación Santa Fe de Bogotá between January 1, 2021 and December 31, 2025. Patients will be identified through institutional oncology, chemotherapy pharmacy and surgical pathology databases, and all eligible patients will be included (census sampling; approximately 90 patients). Data collection will start only after notification of the study to INVIMA (Colombian regulatory agency) as a phase IV observational study.

Data collection and outcome ascertainment: Data will be recorded in an institutional REDCap database with pseudonymized study codes and validation rules. Outcomes will be identified through a systematic multi-source search (surgical pathology reports, oncology records, chemotherapy pharmacy records, imaging reports, emergency, inpatient and consultation notes). Key events (pathological response, toxicity, progression and recurrence) will be independently adjudicated by two investigators, with disagreements resolved by consensus, and a random 10% sample of records will be double-checked for data-entry quality. Follow-up runs from FLOT initiation (index date) until recurrence, death, end of follow-up or loss to follow-up.

Outcomes: The primary outcome is pathological response in the institutional surgical specimen, reported as the Mandard tumor regression grade (TRG) and the pathological complete response rate. Secondary outcomes include grade 3-4 adverse events according to CTCAE version 5.0, dose modifications (reduction, delay or discontinuation) and their reasons, adherence and completion of the planned perioperative regimen, cumulative incidence of recurrence and overall survival.

Statistical analysis: The analysis will be exclusively descriptive, without significance testing or causal inference, using available cases with explicit denominators and no imputation. Categorical variables will be summarized as frequencies and proportions with Wilson 95% confidence intervals, and continuous variables as means and standard deviations or medians and interquartile ranges. Results will be stratified by prespecified categories (stage, Lauren subtype, TRG). Overall survival will be estimated with the Kaplan-Meier method from FLOT initiation, with probabilities at 12, 24 and 36 months. Recurrence will be described from the date of R0 resection with the cumulative incidence function (Aalen-Johansen estimator), treating death without recurrence as a competing event. Analyses will be performed in R.

Ethics: The study is classified as research without risk under Colombian Resolution 8430 of 1993, with a waiver of informed consent for retrospective record review. The protocol (version 3.0, July 29, 2026) was approved by the Comité Corporativo de Ética en Investigación of Fundación Santa Fe de Bogotá (CCEI-20373-2026). Data will be handled in accordance with the Declaration of Helsinki (2024 revision) and Colombian Law 1581 of 2012.

Study Type

Observational

Enrollment (Estimated)

90

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • Colombia
    • Bogota D.C.
      • Bogotá, Bogota D.C., Colombia
        • Hospital Universitario Fundación Santa Fe de Bogotá

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Adults older than 18 years with histologically confirmed stage I, II or III gastric or gastroesophageal junction adenocarcinoma who started perioperative FLOT chemotherapy at Hospital Universitario Fundación Santa Fe de Bogotá (Bogotá, Colombia) between January 1, 2021 and December 31, 2025, identified through institutional oncology, chemotherapy pharmacy and surgical pathology databases.

Description

Inclusion Criteria:

  • Patients older than 18 years with histologically confirmed stage I, II or III adenocarcinoma of the stomach or gastroesophageal junction.
  • Initiation of perioperative FLOT chemotherapy at Fundación Santa Fe de Bogotá between January 1, 2021 and December 31, 2025.
  • Sufficient clinical and treatment information to classify the patient and evaluate at least one study outcome (pathological response, toxicity, treatment adherence and completion, recurrence or vital status).

Exclusion Criteria:

  • Metastatic (stage IV) disease documented at initial diagnosis, before starting perioperative FLOT.
  • Gastric or gastroesophageal junction tumors of non-adenocarcinoma histology (for example, lymphoma, gastrointestinal stromal tumor or neuroendocrine carcinoma).
  • Lack of the minimum information required for classification (no record of the FLOT regimen received, of clinical or pathological stage, or of at least one assessment of the primary outcome).
  • Oncology follow-up performed exclusively outside the institution, without adequate traceability of postoperative and long-term outcomes.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: COHORT
  • Time Perspectives: RETROSPECTIVE

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Perioperative FLOT Cohort
Drug: FLOT Chemotherapy

Perioperative chemotherapy with 5-fluorouracil, leucovorin, oxaliplatin and docetaxel (FLOT), planned as four preoperative and four postoperative cycles or modified according to routine clinical practice, combined with gastrectomy. The study does not assign or modify treatment; exposure data are abstracted retrospectively from medical records.

Other Names:
  • Leucovorin
  • 5-Fluorouracil
  • Oxaliplatin
  • FLOT
  • Docetaxel

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Pathological Complete Response Rate
Time Frame: At surgical resection, after completion of preoperative FLOT (approximately 8 to 12 weeks after FLOT initiation)
At surgical resection, after completion of preoperative FLOT (approximately 8 to 12 weeks after FLOT initiation)

Secondary Outcome Measures

Outcome Measure
Time Frame
Tumor Regression Grade (Mandard)
Time Frame: At surgical resection, after completion of preoperative FLOT (approximately 8 to 12 weeks after FLOT initiation)
At surgical resection, after completion of preoperative FLOT (approximately 8 to 12 weeks after FLOT initiation)
Incidence of Grade 3-4 Adverse Events
Time Frame: From FLOT initiation until 30 days after the last FLOT dose, up to approximately 8 months
From FLOT initiation until 30 days after the last FLOT dose, up to approximately 8 months
Proportion of Patients With FLOT Dose Modifications
Time Frame: From FLOT initiation until the last FLOT dose, up to approximately 8 months
From FLOT initiation until the last FLOT dose, up to approximately 8 months
Completion of Planned Perioperative FLOT
Time Frame: From FLOT initiation until the last FLOT dose, up to approximately 8 months
From FLOT initiation until the last FLOT dose, up to approximately 8 months
Cumulative Incidence of Recurrence
Time Frame: From R0 resection until recurrence, death or last follow-up, assessed at 12, 24 and 36 months (up to approximately 6 years)
From R0 resection until recurrence, death or last follow-up, assessed at 12, 24 and 36 months (up to approximately 6 years)
Overall Survival
Time Frame: From FLOT initiation until death or last follow-up, assessed at 12, 24 and 36 months (up to approximately 6 years)
From FLOT initiation until death or last follow-up, assessed at 12, 24 and 36 months (up to approximately 6 years)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Fundación Santa Fe de Bogota

Investigators

  • Principal Investigator: Henry Alexander Vargas Díaz, MD, Fundación Santa Fe de Bogotá

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

October 1, 2026

Primary Completion (Estimated)

October 1, 2027

Study Completion (Estimated)

October 1, 2027

Study Registration Dates

First Submitted

September 29, 2026

First Submitted That Met QC Criteria

September 29, 2026

First Posted (Actual)

October 5, 2026

Study Record Updates

Last Update Posted (Actual)

October 5, 2026

Last Update Submitted That Met QC Criteria

September 29, 2026

Last Verified

September 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • CCEI-20373-2026

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared. Data are obtained from a retrospective review of medical records under a waiver of informed consent and are protected under Colombian personal data protection law (Law 1581 of 2012). Aggregated results will be published in a peer-reviewed journal.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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