Home›Allergy & Immunology› Proposed CTS protocol aims to convert cold tumors to hot and improve immunotherapy response
Proposed CTS protocol aims to convert cold tumors to hot and improve immunotherapy responseNew Strategy Aims to Turn Cold Tumors Hot for Treatment
Frontiers in MedicinePublished July 16, 2026Study authors: Kumara Swamy, Guruaj Arakeri, Ramaswamy Veena, Anirudh Vagata Srinivas, Amritanshu Ram, Agrahara Sre…DOI ↗Editorial oversight: Dr. Amelia Tan, PhD · Internal Medicine & Chronic Disease
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Key Takeaway
Consider the CTS protocol as a hypothesis requiring validation before clinical application.
This systematic review proposes a novel pharmacological strategy called the Combinations, Timing, and Sequencing (CTS) protocol, designed to overcome tumor heterogeneity and improve immunotherapy response. The protocol integrates vascular normalization, epigenetic modifiers, trimodal radiotherapy or stereotactic body radiotherapy (SBRT), chemotherapy, and immunotherapy optimization. Its primary goal is to convert immunologically 'cold' tumors into 'hot', immunotherapy-responsive lesions while minimizing toxicities.
Secondary objectives include reverting mesenchymal phenotypes, normalizing the vasculature, curtailing the recruitment of myeloid-derived suppressor cells (MDSCs) and regulatory T (Treg) cells, and restoring cytotoxic T-cell homing. The authors aim to rescue the immune-suppressive tumor microenvironment through this multi-modal approach.
No pooled effect sizes, patient populations, or comparative data are reported. The authors acknowledge that the CTS protocol is a hypothesis for implementation, not an established clinical standard. Safety data, including adverse events and tolerability, are not reported.
Clinicians should interpret this proposal as a conceptual framework requiring validation in clinical trials before any practice implications can be drawn.
How this fits prior evidence
This systematic review proposes a novel CTS protocol to convert cold tumors to hot, extending prior work on scavenger receptor-guided nanodelivery systems for macrophage modulation and gut microbiome taxa that enhance ICI efficacy. It addresses the gap of tumor heterogeneity not fully covered by lncRNA signatures predicting ICI response. The protocol also aims to mitigate multi-organ immune-related adverse events associated with ICIs, such as acute kidney injury and myocarditis, and offers a potential strategy beyond agents like hangeshashinto for chemotherapy-induced oral mucositis.
Researchers have proposed a new approach called the CTS protocol to improve how cancer treatments work. This method combines several different strategies, including vascular normalization and epigenetic modifiers, with radiation and chemotherapy. The goal is to change the environment around a tumor from 'cold' to 'hot,' making it easier for the immune system to recognize and attack the cancer.
The plan focuses on fixing specific issues in the tumor area, such as improving blood flow and reducing cells that normally block the immune response. By addressing these factors, the strategy aims to make tumors more responsive to immunotherapy while trying to reduce harmful side effects for patients.
It is important to note that this CTS protocol is currently a proposed hypothesis rather than an established medical standard. While it offers a promising way to handle complex tumor types, it has not yet been proven in clinical practice. Patients should discuss new treatment strategies with their oncology team.
What this means for you:
The CTS protocol is a proposed strategy to make tumors more responsive to immunotherapy by changing the local environment.
Common questions
What is the goal of the CTS protocol?
The goal of the CTS protocol is to rescue the immune-suppressive tumor microenvironment. It aims to convert 'cold' tumors into 'hot' ones, which makes them more responsive to immunotherapy. This is done by addressing issues like blood flow and cells that block the immune system from working effectively.
How does this approach differ from standard treatments?
While standard treatments focus on the tumor itself, this proposed strategy uses a combination of vascular normalization, epigenetic modifiers, radiation, and chemotherapy. It specifically targets the environment around the tumor to overcome heterogeneity and improve how the body's immune system responds to treatment.
Is this treatment available for patients now?
No, the CTS protocol is currently a proposed hypothesis and not an established clinical standard. Because it is still in the proposal stage, you should speak with your doctor or oncologist to discuss current approved treatments and how new research might apply to your specific case.
Since the introduction of the hallmarks of cancer framework over 25 years ago, treatment approaches have evolved into personalized medicine, offering benefits to select patient populations. However, three major components of heterotypic interactions in cancer—mutational evolution of cancer stem cells, epithelial-mesenchymal plasticity (EMP), and cancer-remodeled extracellular matrix (ECM)—remain critical barriers to therapy, particularly in patients who have failed treatment. EMP encompasses a spectrum of to-and-fro transitions between mesenchymal and epithelial states, yielding hybrid phenotypes of evolutionary heterogeneity. These are embedded in the vascular, metabolic, mutational, and immune-suppressive reprogramming of the tumor microenvironment (TME), induced and advanced by the hypoxia–reactive oxygen species (ROS)–hypoxia-inducible factor-1α (HIF-1α)–transforming growth factor-β (TGF-β) signaling axis. This review systematically examines the molecular mechanisms underlying EMP, tumor heterogeneity, and the hallmarks of cancer. It explores pharmacological strategies to target tumor burden, epigenetically revert transitional states, and restore immune-editing functions. Based on this analysis, we propose a phased anti-hallmark Combinations, Timing, and Sequencing (CTS) protocol. The methodology integrates vascular normalization, epigenetic modifiers, trimodal radiotherapy or stereotactic body radiotherapy (SBRT), chemotherapy (CT), and immunotherapy optimization, aiming to improve outcomes while minimizing toxicities. Also, mechanistically, by reverting mesenchymal phenotypes and normalizing the vasculature, the CTS protocol is designed to rescue the immune-suppressive tumor microenvironment—curtailing the recruitment of myeloid-derived suppressor cells (MDSCs) and regulatory T (Treg) cells. This restores cytotoxic T-cell homing, thereby converting immunologically “cold” tumors into “hot,” immunotherapy-responsive lesions.
