Chronic inflammation has been recognized as both a contributor to and suppressor of cancer, depending on the specific biological context. Key molecular pathways and immune cells—including NF-κB, IL-6, STAT3, tumor-associated macrophages (TAMs), myeloid-derived suppressor cells (MDSCs), and regulatory T cells (Tregs)—are known to create an environment that supports tumor growth.
Recent research published in the Journal of Exploratory Research in Pharmacology reviews how inflammation drives all stages of cancer development and affects responses to immunotherapy. The review highlights that up to 20% of cancers are linked to chronic infections, autoimmune diseases, or environmental factors. It also notes that since Virchow's observations in the 19th century, inflammation has become established as a hallmark of cancer.
The article discusses several signaling pathways—such as NF-κB and STAT3—that promote cell survival, blood vessel formation within tumors, and suppression of anti-tumor immunity. The COX-2/PGE2 pathway is identified for its role in promoting cell proliferation and recruiting MDSCs.
Immune cells like M2-polarized TAMs, MDSCs, Tregs, and N2 neutrophils are highlighted for their role in suppressing the body's ability to fight tumors. New technologies such as single-cell analyses have helped reveal heterogeneity among these immune populations and potential targets for therapy.
Other mechanisms discussed include activation of the NLRP3 inflammasome and epigenetic changes that maintain chronic inflammatory cycles within tumors.
The review details recent advances in immunotherapy:
- Immune checkpoint inhibitors targeting PD-1/PD-L1/CTLA-4 have shown response rates between 20–40%, but high levels of IL-6 may predict resistance.
- LAG-3 blockade with relatlimab was approved in 2024.
- CAR-T cell therapies remain effective primarily for blood cancers; efforts using CRISPR-edited CAR-T cells aim to improve outcomes in solid tumors.
- Personalized vaccines based on neoantigens and investigational use of oncolytic viruses are being studied alongside anti-inflammatory agents.
- Tumor-infiltrating lymphocyte (TIL) therapy shows efficacy in melanoma with enhancements under development through gene editing techniques.
Emerging treatments such as bispecific T-cell engagers (BiTEs) and antibody-drug conjugates (ADCs) target inflammatory markers for more precise delivery. Drug repurposing efforts show aspirin can reduce colorectal cancer risk while statins are being evaluated for similar benefits.
Several drugs targeting cytokines—including tocilizumab (anti-IL6R), siltuximab (anti-IL6), and infliximab (anti-TNF)—are currently undergoing clinical trials. In particular, studies beginning in 2025 will combine IL-6 blockers with immune checkpoint inhibitors for pancreatic cancer treatment.
Inhibitors targeting NF-kB or STAT3 signaling pathways are also being explored; bortezomib is noted for its suppression of NF-kB activity while new STAT3 inhibitors show promise preclinically by reducing MDSC populations.
Preclinical models such as humanized mice combined with multiomics approaches help researchers better understand spatial inflammatory niches within tumors. Lipid nanoparticles are being used experimentally to reprogram TAMs toward a phenotype less supportive of tumor growth.
Biomarkers including CRP, IL-6 levels, neutrophil-to-lymphocyte ratio (NLR), pan-immune-inflammation value (PIV), PD-L1 expression by immunohistochemistry (IHC), tumor mutational burden (TMB), microsatellite instability status (MSI), circulating tumor DNA signatures, and microbiome profiles assist clinicians in predicting prognosis or likely response to immunotherapies.
Combination strategies under investigation include pairing immune checkpoint inhibitors with aspirin or VEGF inhibitors as well as combining them with chemotherapy or radiation. Recent trials also explore integrating microbiome modulators into colorectal cancer treatment protocols involving immunotherapy agents.
Management strategies for immune-related adverse events from these therapies involve corticosteroids or TNF inhibitors; soluble CD25 serves as a marker predicting risk for complications.
Personalized medicine approaches increasingly rely on artificial intelligence-driven analysis of multiomic data sets to tailor patient care plans dynamically during treatment courses. Microbiome composition—specifically higher levels of Bifidobacterium or Akkermansia—has been associated with better responses to immunotherapy; ongoing studies evaluate fecal microbiota transplantation and CRISPR-based interventions aimed at modulating gut flora composition.
AI models now predict patient prognosis or likelihood of resistance against certain cellular therapies like CAR-T based on integrated imaging/textual data sources—a model developed at Stanford University was highlighted among these advances in 2024. Gene-editing tools such as CRISPR-Cas9 enable researchers to modify genes involved in T-cell exhaustion while RNA editing offers reversible control over gene expression relevant to therapy resistance mechanisms.
Single-cell omics combined with spatial mapping technologies allow identification of distinct clusters within tumors contributing either directly or indirectly toward therapeutic resistance—integrating this information via AI further refines dynamic maps describing tumor microenvironments over time. Liquid biopsies employing nanotechnology facilitate noninvasive monitoring through detection of circulating DNA bearing signatures reflective not only of malignancy but also underlying inflammatory states relevant for real-time adjustment during treatment regimens.
New opportunities continue emerging: ADC-delivered anti-inflammatory payloads target resistant disease subtypes; rational combinations simultaneously inhibiting parallel signaling pathways like NF-kB plus STAT3 hold promise; germline pharmacogenomic profiling may eventually guide selection/personalization around anti-inflammatory interventions.
Chronic inflammation remains central across multiple dimensions influencing cancer initiation/progression/response/resistance patterns—with integration between inflammation-targeted strategies/immunotherapies/biomarker-driven personalization marking a significant direction forward according to current research trends.
