Impact of Serum GDF-15 and IL-6 on Immunotherapy Response in Cancer: A Prospective Study

Immunotherapy has transformed cancer treatment; however, predicting treatment response remains challenging. Serum biomarkers can help identify patients who are most likely to benefit from immunotherapy.

This study evaluates the relationship between serum growth differentiation factor 15 (GDF-15) and interleukin-6 (IL-6) levels and treatment outcomes in cancer patients undergoing second-line immunotherapy.

We conducted a prospective observational study involving 85 patients with non-small-cell lung cancer (NSCLC), renal cell carcinoma (RCC), or malignant melanoma treated with nivolumab. The baseline serum levels of GDF-15 and IL-6 were measured by using ELISA kits. The primary endpoints were progression-free survival (PFS) and overall survival (OS), with cachexia as a secondary outcome.

Elevated GDF-15 levels were significantly associated with shorter PFS (HR: 0.55, 95% CI: 0.32-0.96, p = 0.032) and OS (HR: 0.47, 95% CI: 0.25-0.90, p = 0.020). Higher IL-6 levels correlated with shorter PFS, though statistical significance was not achieved. Additionally, high GDF-15 levels were linked to increased cachexia incidence (p = 0.037).

Our findings indicate that GDF-15 could serve as a prognostic biomarker for immunotherapy response and may also be a target for cachexia management. Further studies should explore its potential to guide clinical decision making in oncology.