title: A pilot study examining circulating interleukin-6 and transforming growth factor-β levels during pelvic radiation therapy.
abstract: OBJECTIVE
  To determine if circulating levels of the inflammatory cytokines interleukin-6 (IL-6) and transforming growth factor-β (TGF-β levels) are elevated during pelvic radiotherapy (RT).
  
  
  METHODS
  Patients receiving pelvic RT with a minimum dose of 45 Gy were eligible for this prospective observational study. Patients were assessed before RT, during week 3 of RT, and during the last week of RT. Assessment included determination of gastrointestinal toxicity and laboratory evaluation for serum IL-6 and plasma TGF-β using quantitative 2-site enzyme immunoassays. Dose to the rectum, colon, and small bowel were analyzed using dose-volume histograms. A 2-sided 0.05-level Kruskal Wallis one-way analysis of variance test was used to test the equality of the means of IL-6 and TGF-β levels at the different time points.
  
  
  RESULTS
  Twenty patients were enrolled, of whom 18 were eligible. The mean (95% confidence interval) serum IL-6 levels at baseline, 3 weeks, and during the last week of RT were 5.1 (1.9-8.3) pg/mL, 4.1 (2.6-5.7) pg/mL, and 7.5 (4.9-10.1) pg/mL, respectively (P-value > 0.05). The mean (95% confidence interval) plasma TGF-β levels at baseline, 3 weeks, and during the last week of RT were 8.7 (5.0-12.3) ng/mL, 5.5 (3.8-7.2) ng/mL, and 7.0 (4.5-9.5) ng/mL, respectively (P-value > 0.05). There was no correlation between cytokine levels and clinically evident RT enteritis or volume of bowel receiving RT.
  
  
  CONCLUSIONS
  We did not observe significant changes in circulating levels of TGF-β and IL-6 during pelvic RT.
authors: Department of Radiation Oncology, Mayo Clinic, Rochester, MN 55905, USA.
authors: Christopher L
authors: CL
authors: Hallemeier
authors: Matt J
authors: MJ
authors: Iott
authors: James A
authors: JA
authors: Martenson
authors: Michael G
authors: MG
authors: Haddock
authors: Xinghua Cathy
authors: XC
authors: Zhao
authors: Robert C
authors: RC
authors: Miller
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D014408:Biomarkers, Tumor / Q000097:blood*; D015331:Cohort Studies; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods; D010386:Pelvic Neoplasms / Q000097:blood* / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D010865:Pilot Projects; D011446:Prospective Studies; D011879:Radiotherapy Dosage; D011882:Radiotherapy, High-Energy / Q000009:adverse effects / Q000379:methods; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012737:Sex Factors; D015996:Survival Rate; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000097:blood*; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; D015850:Interleukin-6; D016212:Transforming Growth Factor beta