Conversion Therapy Plus Surgery and Radiotherapy for Retroperitoneal Nodal Metastases in Gastric Cancer
A Randomized, Controlled, Multicenter Phase II Study of Conversion Therapy Combined With Surgery and Radiotherapy for Retroperitoneal Lymph Node Metastases in Gastric Cancer
Jinbo Yue
54 participants
Oct 1, 2025
INTERVENTIONAL
Conditions
Summary
This is a randomized, controlled, multicenter phase II clinical trial evaluating the efficacy and safety of conversion therapy combined with radical gastrectomy and adjuvant radiotherapy targeting para-aortic (station 16) lymph nodes in patients with gastric adenocarcinoma and isolated station 16 nodal metastases. Eligible participants must have no evidence of peritoneal dissemination, visceral metastases, or non-regional lymphatic spread. Based on PD-L1 combined positive score (CPS), patients in the experimental arm will receive systemic therapy with SOX (S-1 plus oxaliplatin) with or without a PD-1 inhibitor, followed by D2 gastrectomy and postoperative adjuvant SOX chemotherapy, then intensity-modulated radiotherapy (IMRT) to the para-aortic region. The control arm will receive standard chemotherapy with CAPEOX or SOX, with or without immunotherapy, according to CPS status. The primary endpoint is progression-free survival (PFS), with secondary endpoints including overall survival (OS), objective response rate (ORR), disease control rate (DCR), and safety. This study aims to explore whether the addition of locoregional treatment to systemic therapy improves long-term outcomes in this select patient population.
Eligibility
Inclusion Criteria1
- Histologically confirmed gastric adenocarcinoma with isolated para-aortic (station 16) lymph node metastasis; pMMR or MSS subtype; ECOG performance status 0-2; Life expectancy ≥ 3 months; Adequate organ function (hematologic, hepatic, renal); Ability to provide tumor tissue for biomarker analysis; Ability to understand and willingness to sign written informed consent; Women of childbearing potential must have a negative pregnancy test and agree to use effective contraception during study and for 12 months after treatment; men with partners of childbearing potential must also agree to contraception.
Exclusion Criteria1
- Evidence of visceral or peritoneal metastasis; MSI-H or dMMR subtype; HER2-positive disease (IHC 3+ or IHC 2+ with FISH positive); Prior systemic anti-tumor therapy; Prior malignancy within 3 years (except adequately treated basal cell/squamous cell carcinoma of the skin or in situ carcinoma); Prior PD-1/PD-L1/CTLA-4 therapy; Participation in another interventional trial within 4 weeks; Active autoimmune disease requiring systemic therapy within past 2 years; Uncontrolled infection, hepatitis B, C, or HIV; CNS metastases or carcinomatous meningitis; Uncontrolled cardiovascular disease (unstable angina, recent MI, NYHA III-IV heart failure, QTc ≥480 ms); Interstitial lung disease or uncontrolled pulmonary disease; Uncontrolled diabetes mellitus (FBG >10 mmol/L); Pregnancy or breastfeeding; Major surgery within 4 weeks prior to randomization; Any other condition that may interfere with protocol compliance or increase risk as judged by the investigator.
Interested in this trial?
Get notified about updates and connect with the research team.
Interventions
The SOX regimen consists of oxaliplatin 130 mg/m² IV on day 1 plus oral S-1 (tegafur/gimeracil/oteracil) 40-60 mg twice daily, taken on days 1-14 followed by 7 days off, in a 21-day cycle. Experimental arm: 3 cycles before surgery, 5 cycles after surgery. Control arm: up to 8 cycles as standard systemic therapy.
The CAPEOX regimen consists of oxaliplatin 130 mg/m² IV on day 1 plus oral capecitabine 1000 mg/m² twice daily on days 1-14, repeated every 3 weeks (q3w), up to 8 cycles. Used as a standard chemotherapy option in the control arm, with or without PD-1 inhibitor according to PD-L1 CPS score.
A PD-1 inhibitor is administered intravenously at a fixed dose of 200 mg every 3 weeks. It is combined with SOX in the experimental arm (CPS ≥1 patients) during conversion and adjuvant phases, and with CAPEOX or SOX in the control arm (CPS ≥1 patients). Maintenance PD-1 inhibitor continues for up to 1 year or until disease progression or unacceptable toxicity.
Intensity-modulated radiotherapy (IMRT) is delivered postoperatively to the para-aortic (station 16) nodal basin. Elective nodal basin: 45-50 Gy in 25 fractions Positive nodes: 56-60 Gy in 25 fractions Radiotherapy is given concurrently with oral capecitabine or S-1 as radiosensitizers.
During para-aortic IMRT, patients receive concurrent oral capecitabine 825 mg/m² twice daily on radiation days, or oral S-1 dosed according to body surface area. These agents are used as radiosensitizers during postoperative radiotherapy.
Locations(1)
View Full Details on ClinicalTrials.gov
For the most up-to-date information, visit the official listing.
NCT07007182