FOLFIRINOX Induction Chemotherapy for Synchronous Liver Metastases (SYNCHRONOX)

Multicenter Cohort Study of Mid/Lower Rectal Cancer With Resectable Synchronous Liver Metastases Treated With FOLFIRINOX Induction Chemotherapy

SYNCHRONOX is a multicenter cohort (retrospective then prospective) intending to include 550 patients with mid or low rectal adenocarcinoma (pMMR, T3-T4 and/or N+) and resectable synchronous liver metastases, treated upfront with at least two cycles of induction FOLFIRINOX chemotherapy. The primary objective is to determine, at 18 months, the R0 resection rate of both tumor sites (rectum and liver), while secondary objectives focus on 3 year overall and progression free survival, radiological and pathological responses, postoperative morbidity and mortality, and comparison of the different surgical strategies after FOLFIRINOX.

Study Overview

• Status: Recruiting
• Conditions: Rectal Cancer; Antineoplastic Combined Chemotherapy Protocols; Synchronous Liver Metastases; Surgical Therapy

Detailed Description

SYNCHRONOX is a multicenter, observational retrospective cohort followed by a prospective validation cohort designed to evaluate therapeutic pathways and oncologic outcomes in adults with mid- or low-rectal adenocarcinoma and resectable synchronous liver metastases who received induction FOLFIRINOX chemotherapy. The study aims to describe and compare real-world management strategies after induction FOLFIRINOX (simultaneous rectum and liver surgery, "classic" rectum-first, "reverse" liver-first, and adaptive sequencing) and to identify factors associated with achieving complete curative-intent treatment of both tumor sites.

Eligible patients are ≥18 years old with pMMR mid/low rectal adenocarcinoma staged cT3-T4 and/or N+, with synchronous liver metastases diagnosed within 3 months before or after the rectal cancer diagnosis, without extrahepatic metastases, and treated with at least two cycles of induction FOLFIRINOX. Liver disease is considered resectable when lesions are unilobar (no limit in number) or bilobar with up to 10 lesions, corresponding to class I (clearly resectable with a conventional hepatectomy of ≤4 segments leaving >40% remnant liver) or class II (potentially resectable, requiring complex/extended liver surgery and possibly two-stage strategies). Because this is a non-interventional study, all diagnostic work-up, chemotherapy, radiotherapy, surgical decisions, and follow-up are performed as part of routine care and remain at the discretion of local multidisciplinary tumor boards. The research does not mandate any additional clinical, laboratory, radiologic examinations, surgical procedures, or questionnaires.

The primary endpoint is the rate of curative-intent complete treatment (R0) of both tumor sites at 18 months after the start of induction FOLFIRINOX. For rectal cancer, R0 resection is defined as a distal margin ≥1 cm and a circumferential resection margin >1 mm. Organ preservation without surgery is also considered curative-intent when achieved after a clinical complete response and not followed by tumor regrowth within the first year. For liver metastases, curative-intent treatment requires R0 resection of all visible lesions (margin >1 mm) and/or local destruction by radiofrequency ablation.

Secondary objectives include overall survival and progression-free survival at 3 years from the start of FOLFIRINOX, R0 resection rates for the rectal primary and liver metastases separately, radiologic response assessment at both sites (ymrTRG for rectal MRI response and RECIST for liver lesions), pathologic tumor regression grading (Rödel score for rectal cancer and Blazer classification for liver metastases), clinical complete response rate of the rectal tumor, and 30-day postoperative morbidity and mortality after rectal and liver surgery (Dindo-Clavien classification). Data are collected in an electronic case report form (eCRF) from standard medical records for both retrospective and prospective cohorts, with planned comparative analyses between strategies using matching variables and propensity-score methods to limit indication bias. The retrospective cohort includes patients diagnosed between June 1, 2020 and June 1, 2025, and the prospective validation cohort includes patients diagnosed between June 1, 2025 and June 1, 2028, with an overall follow-up duration of 60 months.

• Study Type: Observational
• Enrollment (Estimated): 550

Contacts and Locations

• Study Contact: Name: Stéphane BENOIST, MD PhD; Phone Number: +33 (0)1 45 21 34 72; Email: stephane.benoist@aphp.fr
• Study Contact Backup: Name: Solafah ABDALLA, MD PhD; Phone Number: +33 (0)1 45 21 34 70; Email: solafah.abdalla@aphp.fr

Study Locations

• France
  • Le Kremlin-Bicêtre, France, 94270
    • Recruiting
    • Digestive Surgery Department, Bicêtre University Hospital AP-HP
    • Contact: Stéphane BENOIST, MD PhD; Phone Number: +33 (0)1 45 21 34 72; Email: stephane.benoist@aphp.fr
    • Contact: Solafah ABDALLA, MD PhD; Phone Number: +33 (0)1 45 21 34 70; Email: solafah.abdalla@aphp.fr
    • Principal Investigator: Stéphane BENOIST, MD PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patients with mid/lower rectal cancer with resectable synchronous liver metastases, treated with FOLFIRINOX induction chemotherapy

Description

Inclusion Criteria:

• Adult subjects aged 18 years and older
• Adenocarcinoma of the middle and/or lower rectum pMMR T3, T4, and/or N+
• Resectable synchronous liver metastases

Exclusion Criteria:

• Minor under the age of 18.
• Presence of extrahepatic metastases
• Induction chemotherapy with FOLFIRINOX of less than 2 courses

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
Patients with rectal cancer with resectable synchronous liver metastases, treated with FOLFIRINOX; Follow-up as part of the usual care of patients with mid/lower rectal cancer with resectable synchronous liver metastases, treated with FOLFIRINOX induction chemotherapy.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Curative resection rate of both tumor sites after induction chemotherapy with FOLFIRINOX	For rectal cancer, resection is considered curative in cases of R0 resection (distal margin ≥ 1 cm and circumferential resection margin > 1 mm). Non-surgical organ preservation is also considered curative treatment in cases of complete clinical response not followed by tumor regrowth during the first year. For liver metastases, resection is considered curative if all visible lesions have been resected R0 (resection margin > 1 mm) or destroyed by radiofrequency.	18 months from the start of chemotherapy with FOLFIRINOX

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Overall 3-year survival rate	The length of time from the start of FOLFIRINOX chemotherapy until death.	3 years from the start of chemotherapy with FOLFIRINOX
Three-year progression-free survival rate	Survival is calculated from the start of treatment with FOLFIRINOX chemotherapy. Any progression during preoperative treatment preventing complete resection for curative purposes, the discovery of a contraindication to surgery during the operation, and the occurrence of recurrence after surgery will be considered an event.	3 years from the start of chemotherapy with FOLFIRINOX
Complete resection rate (R0) of rectal tumors	Resection is considered complete (R0) if the distal margin is ≥ 1 cm and the circumferential resection margin is > 1 mm.	30 days after rectal resection
Complete resection rate (R0) of liver lesions	Resection is considered complete (R0) if the resection margin is > 1 mm.	30 days after liver resection
Radiological response grade of rectal tumor to preoperative treatment	The radiological response will be assessed using the Magnetic Resonance Tumor Regression Grade (ymrTRG), a five-grade scale ranging from 1 (complete response) to 5 (no response).	1 month after the end of neoadjuvant therapy
Radiological response grade of liver lesions to preoperative treatment	The radiological response will be assessed using the RECIST score (partial response (response > 30%), complete response (response 100%), progression (increase in lesion size > 20%), stability (progression < 20% and response < 30%)).	1 month after the end of FOLFIRINOX
Histological response grade of rectal tumor to preoperative treatment	The histological response grade will be assessed according to the Rödel score, a five-grade scale ranging from 0 (zero regression) to 4 (complete response).	30 days after rectal resection
Histological response grade of liver lesions to preoperative treatment	The histological response grade is estimated according to Blazer. The Blazer score identifies three subgroups: 1. Complete response: absence of residual cancer cells; 2. Major response: presence of 1% to 49% of residual cancer cells; 3. Minor response: presence of ≥ 50% of residual cancer cells. In patients with multiple tumor nodules, the average of the values for the different nodules will be used to define the pathological response.	30 days after liver resection
Complete clinical response rate of rectal tumors	Complete clinical response is defined by a complete radiological response on MRI (ymrTRG1) and no palpable lesion on digital rectal examination, and on endoscopy, no visible tumor or only a residual whitish scar without ulceration.	1 month after neoadjuvant treatment
Postoperative complication rate following rectal surgery	Postoperative complication rates according to Dindo-Clavien (1=minor medical treatment; 2=antibiotic therapy, transfusion, parenteral nutrition; 3=surgical treatment, interventional radiology or endoscopy; 4=hospitalization in intensive care unit; 5=death).	30 days post operative
Postoperative complication rate following liver surgery	Postoperative complication rates according to Dindo-Clavien (1=minor medical treatment; 2=antibiotic therapy, transfusion, parenteral nutrition; 3=surgical treatment, interventional radiology or endoscopy; 4=hospitalization in intensive care unit; 5=death).	30 days post operative
Postoperative mortality rate following rectal surgery	Death within 30 days following rectal surgery.	30 days post operative
Postoperative mortality rate following liver surgery	Death within 30 days following liver surgery.	30 days post operative

Collaborators and Investigators

• Sponsor: Assistance Publique - Hôpitaux de Paris

Study record dates

Study Major Dates

• Study Start (Actual): May 1, 2026
• Primary Completion (Estimated): November 1, 2030
• Study Completion (Estimated): May 1, 2034

Study Registration Dates

• First Submitted: March 8, 2026
• First Submitted That Met QC Criteria: March 8, 2026
• First Posted (Actual): March 12, 2026

Study Record Updates

• Last Update Posted (Actual): June 9, 2026
• Last Update Submitted That Met QC Criteria: June 5, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Prospective observational multicentric cohort; Retrospective observational multicentric cohort
• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Intestinal Diseases; Gastrointestinal Neoplasms; Digestive System Neoplasms; Digestive System Diseases; Gastrointestinal Diseases; Colorectal Neoplasms; Intestinal Neoplasms; Rectal Diseases; Rectal Neoplasms
• Other Study ID Numbers: APHP251682

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No