title: Faecal DNA and calprotectin as biomarkers of acute intestinal toxicity in patients undergoing pelvic radiotherapy.
abstract: BACKGROUND
  Acute intestinal toxicity is a frequent complication that may lead to interruption of treatment in patients undergoing pelvic radiotherapy. Reliable, non-invasive biological markers to evidence their severity are not yet available.
  
  
  OBJECTIVE
  To test faecal DNA and calprotectin as potential biomarkers of intestinal toxicity caused by pelvic radiotherapy.
  
  
  METHODS
  Patients were categorized according to the location of the cancer as nonrectal (n = 25) and rectal (n = 27). Four stool samples were collected at weeks w0, w3, w5 (end of radiotherapy) and w7. Faecal DNA was determined by quantitative PCR and calprotectin by ELISA. Intestinal toxicity was scored according to the Common Toxicity Criteria.
  
  
  RESULTS
  In the nonrectal group, acute diarrhoea toxicity was present in 80% of patients, faecal DNA increased 10-fold during radiotherapy (1.5 x 10(3) copies/mg dry weight, 9.5 x 10(2)-8.8 x 10(3) at w0, median and interquartile range vs. 1.3 x 10(4), 1.9 x 10(3)-3.9 x 10(4) at w5, P < 0.01), but was not recovered at w7 (3.4 x 10(3), 1.5 x 10(3)-4.1 x 10(4)) and calprotectin doubled during treatment at w3 and w5. No significant changes in faecal markers were found in the rectal group.
  
  
  CONCLUSIONS
  Faecal excretion of human DNA and calprotectin increased during pelvic radiotherapy treatment, and may be a good objective biomarker of intestinal damage in nonrectal cancer patients.
authors.affiliation: Digestive System Research Unit, University Hospital Vall d'Hebron, Autonomous University of Barcelona, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Barcelona, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Varela
authors.forename: M
authors.initials: M
authors.lastname: Antolín
authors.forename: F
authors.initials: F
authors.lastname: Guarner
authors.forename: R
authors.initials: R
authors.lastname: Verges
authors.forename: J
authors.initials: J
authors.lastname: Giralt
authors.forename: J-R
authors.initials: JR
authors.lastname: Malagelada
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000032:analysis*; D015179:Colorectal Neoplasms / Q000532:radiotherapy*; D005243:Feces / Q000737:chemistry; D005260:Female; D006801:Humans; D039841:Leukocyte L1 Antigen Complex / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D010388:Pelvis; D011832:Radiation Injuries / Q000139:chemically induced / Q000175:diagnosis*; D002583:Uterine Cervical Neoplasms / Q000532:radiotherapy*
chemical_list: D015415:Biomarkers; D039841:Leukocyte L1 Antigen Complex