The Influence of the Pretreatment Immune State on Response to Radiation Therapy in High-Risk Prostate Cancer: A Validation Study From NRG/RTOG 0521

Int J Radiat Oncol Biol Phys. 2022 Oct 1;114(2):266-274. doi: 10.1016/j.ijrobp.2022.05.048. Epub 2022 Jun 5.


Purpose: The immunoinflammatory state has been shown to be associated with poor outcomes after radiation therapy (RT). We conducted an a priori designed validation study using serum specimens from Radiation Therapy Oncology Group (RTOG) 0521. It was hypothesized the pretreatment inflammatory state would correlate with clinical outcomes.

Methods and materials: Patients on RTOG 0521 had serum banked for biomarker validation. This study was designed to validate previous findings showing an association between elevations in C-reactive protein (CRP) and shorter biochemical disease free survival (bDFS). CRP levels were measured in pretreatment samples. An exploratory panel of related cytokines was also measured including: monocyte chemotactic protein-1, granulocyte-macrophage colony-stimulating factor, interferon-γ, interleukin (IL)-1b, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IL-13, IL-17A, IL-23, and tumor necrosis factor. The primary endpoint examined was bDFS. Additional exploratory endpoints included overall survival, distant metastases, and toxicity events attributed to RT.

Results: Two hundred and two patients in RTOG/NRG 0521 had serum samples available. Median age was 66 years (48-83), and 90% of patients were White. There was not an association between CRP and bDFS (adjusted hazard ratio [HR], 1.07 per 1 log increase in CRP; 95% confidence interval, 0.83-1.38; P = .60). In the exploratory, unplanned analysis, pretreatment IL-10 was significantly associated with worse bDFS (adjusted HR, 1.61 per log increase; P = .0027) and distant metastases (HR, 1.55 per log increase; P = .028). The association of IL-10 with bDFS was maintained on a multiplicity adjustment. The exploratory analyses of pretreatment levels of interferon-γ, IL-1b, IL-2, IL-13, IL-23 were negatively associated with grade 2 or higher pollakiuria (adjusted odds ratio, 0.64, 0.65, 0.71, 0.72, and 0.74, respectively, all P < .05), and IL-6 was negatively associated with grade 2 or higher erectile dysfunction (odds ratio, 0.62; P = .027).

Conclusions: Pretreatment CRP was not associated with a poorer bDFS after RT. In a hypothesis- generating analysis, higher baseline levels of IL-10 were associated with lower rates of bDFS. These findings require additional prospective evaluation.

Publication types

  • Validation Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Biomarkers / blood
  • C-Reactive Protein / analysis
  • Cytokines* / blood
  • Disease-Free Survival
  • Humans
  • Immunity*
  • Inflammation* / blood
  • Inflammation* / immunology
  • Male
  • Middle Aged
  • Prostatic Neoplasms* / blood
  • Prostatic Neoplasms* / immunology
  • Prostatic Neoplasms* / radiotherapy


  • Biomarkers
  • Cytokines
  • C-Reactive Protein