ORIGINAL RESEARCH article
Front. Immunol.
Sec. Cancer Immunity and Immunotherapy
Volume 16 - 2025 | doi: 10.3389/fimmu.2025.1670812
This article is part of the Research TopicAdvancing Next-Generation Immunotherapy and Biomarker Discovery: Pioneering the Future of Treatment Strategies in Solid TumorsView all articles
Preliminary study on BRICS sequential therapeutic regimen as salvage treatment for refractory advanced colorectal cancer patients harboring pMMR status
Provisionally accepted
- 1900th Hospital of the People's Liberation Army Joint Logistic Support Force, Fuzhou, China
- 2The Second Affiliated Hospital of Jiaxing University, Jiaxing, China
- 3Quzhou City People's Hospital, Quzhou, China
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Background: Patients with refractory mismatch repair-proficient/microsatellite stable (pMMR/MSS) metastatic colorectal cancer exhibit intrinsic resistance to immune checkpoint inhibitors and conventional salvage therapies, with median overall survival (OS) is typically less than 10 months. This study evaluates the novel BRICS sequential regimen (Bifidobacterium supplementation, Radiotherapy, Immunotherapy, Chemotherapy, Stereotactic approach) in this population. Methods: In this retrospective analysis, 27 refractory pMMR/MSS metastatic CRC patients received BRICS: Stereotactic body radiotherapy to a single lesion, indefinite high-dose probiotics, followed by low-dose chemotherapy plus PD-1 inhibitor. Primary endpoints were objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and OS. Results: Efficacy outcomes: ORR 33.3% (9 partial responses), DCR 88.9%, median PFS 7.20 months (95% CI: 5.23–9.18), and median OS 12.30 months (95% CI: 9.89–14.71). Eastern Cooperative Oncology Group Performance Status (ECOG PS) >2 independently predicted inferior OS (HR=4.860; p=0.042), while metastatic burden (≥3 organs) predicted shorter PFS (HR=3.179; p=0.026). Grade 3–4 adverse events occurred in 22.2% of patients (neutropenia: 14.8%; thrombocytopenia: 3.7%; anemia: 3.7%). Conclusions: BRICS demonstrates clinically meaningful efficacy (DCR 88.9%, mOS 12.3 months) and manageable toxicity in refractory pMMR/MSS metastatic CRC. ECOG PS >2 and high metastatic burden identify patients with limited benefit, warranting prospective validation in biomarker-enriched cohorts.
Keywords: Metastatic colorectal cancer, Mismatch repair-proficient, BRICS regimen, Salvage Therapy, stereotactic body radiotherapy
Received: 22 Jul 2025; Accepted: 04 Sep 2025.
Copyright: © 2025 Peng, Wang, Wang and Chen. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence:
Junhui Wang, Quzhou City People's Hospital, Quzhou, China
Jianxin Chen, Quzhou City People's Hospital, Quzhou, China
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