The study focused on the acute-phase cascade, a systemic inflammatory response that has been correlated with outcome in many different cancers. Cytokines are a main driver of this cascade, and the team reasoned that the soluble cytokine and growth factor profile in a patient’s serum at diagnosis might encode prognostic information that conventional staging misses. They measured six molecules: the growth factors epidermal growth factor, or EGF, and vascular endothelial growth factor, or VEGF; the cytokines interleukin-4 and interleukin-6; and the chemokines interleukin-8 and monocyte chemoattractant protein-1, known as MCP-1. All were quantified using enzyme-linked immunosorbent assay, a plate-based immunoassay in which antibodies capture the target protein from plasma and a colorimetric signal reveals its concentration.

The cohort consisted of 115 patients with head and neck squamous cell carcinoma whose blood was sampled at diagnosis, before treatment with curative intent. Following observation for up to ten years, the researchers determined HNSCC-specific survival, meaning the fraction of patients who did not die from their cancer. The analysis was stratified by HPV status, a distinction that has reshaped the entire field of head and neck oncology. HPV-positive tumors, which arise from virally driven transformation of epithelial cells, behave clinically as a different disease from HPV-negative tumors, which are typically driven by tobacco and alcohol exposure and carry a heavier burden of genomic chaos.

The results reveal a molecular fault line running along that viral divide. High plasma levels of interleukin-6 predicted worse survival among all patients, regardless of HPV status. Interleukin-6 is a pleiotropic cytokine at the heart of the acute-phase response; it drives the liver to produce C-reactive protein and orchestrates a systemic inflammatory state that can promote tumor proliferation, angiogenesis, immune evasion and metastasis. Its elevation in circulation is therefore a plausible readout of a tumor-fueled inflammatory furnace burning within the patient, and its negative prognostic weight across the whole cohort is consistent with a large body of literature linking IL-6 signaling to poor outcomes in solid tumors.

The other four molecules told a different story, one reserved almost exclusively for HPV-positive patients. Increased levels of the chemokines interleukin-8 and MCP-1 predicted worse prognosis among HPV-positive patients, and high levels of the growth factor VEGF at diagnosis showed a trend towards worse outcomes in the same group. Interleukin-8 is a chemokine that recruits neutrophils and promotes angiogenesis, while MCP-1, also known as CCL2, draws monocytes into tumors and can polarize them toward immunosuppressive phenotypes. VEGF, meanwhile, is the canonical driver of tumor angiogenesis, the sprouting of new blood vessels that feed growing tumors. That all three molecules carry negative prognostic weight specifically in HPV-positive disease suggests that the virally driven tumors, despite their generally favorable response to treatment, are vulnerable to a systemic inflammatory and angiogenic milieu in ways that HPV-negative tumors are not.

Epidermal growth factor emerged as the most clinically actionable of the six markers. High levels of EGF predicted decreased overall and HNSCC-specific survival among HPV-positive patients. EGF is the ligand for the epidermal growth factor receptor, or EGFR, a cell-surface signaling hub that drives proliferation, survival and invasion in epithelial cancers and is itself a validated therapeutic target in head and neck squamous cell carcinoma. Circulating EGF at diagnosis may therefore reflect the intensity of EGFR pathway activation in the tumor and the host’s systemic growth factor economy. Receiver operating characteristic analysis demonstrated that, clinically, EGF levels above 2.3 picograms per milliliter yielded more than 75 percent sensitivity and specificity for long-term HNSCC-specific survival in HPV-positive patients. In practical terms, a single plasma EGF measurement at diagnosis, at a threshold of just 2.3 picograms per milliliter, could classify HPV-positive patients into prognostic groups with better than 75 percent accuracy on both ends of the classification.

Not every marker pointed toward doom. Increased levels of interleukin-4 predicted better survival among HPV-negative patients, a finding that runs counter to the general assumption that elevated cytokines signal a worse prognosis. Interleukin-4 is classically associated with type 2 immune responses, driving the differentiation of naive T cells toward Th2 phenotypes and promoting antibody production. Its association with improved survival in HPV-negative disease raises intriguing questions about the role of systemic immune polarization in this tobacco-driven cancer. One possibility is that a type 2-skewed systemic immune environment, rather than reflecting immunosuppression, may correlate with an immune state that restrains tumor progression in HPV-negative tumors, which lack the strong viral antigens that mobilize cytotoxic responses in HPV-positive disease. The authors note that the finding is a correlation, not proof of causation, and that the mechanistic basis remains to be established.

The technical rigor of the study deserves emphasis. The cytokines were determined by ELISA from blood samples obtained at diagnosis, before any treatment, eliminating the confounding effects of surgery, radiation or chemotherapy on circulating protein levels. The survival endpoint was HNSCC-specific survival, which excludes deaths from other causes and therefore isolates the prognostic signal relevant to the cancer itself. The follow-up period of up to ten years is unusually long for biomarker studies in this field, where most analyses stop at three to five years. The stratification by HPV status is equally important, because pooling HPV-positive and HPV-negative patients would have diluted the HPV-specific signals that the study reveals. The study was approved by the Norwegian regional ethics committee and performed in accordance with the Declaration of Helsinki, with all samples collected after written informed consent.

The implications for clinical practice are substantial. At present, prognostication in head and neck squamous cell carcinoma relies on anatomical staging, HPV status, and increasingly on radiomic and genomic features, but systemic inflammatory biomarkers measured in a simple blood draw have not been integrated into routine risk assessment. This study suggests that a panel of six plasma proteins, measured at diagnosis with a standardized immunoassay, could add independent prognostic information. For HPV-positive patients, elevated EGF, IL-8, MCP-1 and VEGF at diagnosis may identify a subgroup at higher risk of dying from their cancer despite the generally favorable prognosis of virally driven disease, potentially justifying treatment intensification or closer surveillance. For HPV-negative patients, high IL-4 may mark a subgroup with better survival, while elevated IL-6 across the board may flag patients whose systemic inflammatory burden is eroding their prognosis.

The study also carries broader scientific weight. It reinforces the concept that cancer is not merely a disease of transformed cells but of the entire systemic environment in which those cells live, including the cytokine economy of the host. The acute-phase cascade, long studied through crude markers such as C-reactive protein and the neutrophil-to-lymphocyte ratio, is now being dissected at the level of individual soluble mediators, and the Norwegian findings show that this dissection reveals prognostic information that varies by viral etiology. The correlation between circulating EGF and survival in HPV-positive patients, with a clinically defined threshold of 2.3 picograms per milliliter, is the kind of finding that could seed prospective validation studies and eventually clinical trials of EGFR pathway monitoring. The work received financial support from the Norwegian Cancer Society and the Norwegian Central Health West authorities, and the authors declare no competing interests. As with all biomarker studies, the next step is independent validation in larger, prospective cohorts, ideally with standardized assay protocols and multiethnic patient populations, before a six-protein plasma panel can move from the research bench to the oncology clinic.

Subject of Research: Cancer

Article Title: Plasma biomarkers and long-term survival in head and neck squamous cell carcinoma patients: insights from EGF, VEGF, IL-4, IL-6, IL-8 and MCP-1 at diagnosis

Article References: Moe, S. E. E., Aarstad, H. H., Erland, F., Lybak, S., & Aarstad, H. J. (2026). Plasma biomarkers and long-term survival in head and neck squamous cell carcinoma patients: insights from EGF, VEGF, IL-4, IL-6, IL-8 and MCP-1 at diagnosis. BMC Cancer. https://doi.org/10.1186/s12885-026-17176-8

Image Credits: AI Generated

DOI: 10.1186/s12885-026-17176-8

Keywords: head and neck cancer, biomarkers, HPV, cytokines, EGF, IL-6, survival, oncology, Plasma, long-term, head, neck