title: Sustaining Blood Lymphocyte Count during Preoperative Chemoradiotherapy as a Predictive Marker for Pathologic Complete Response in Locally Advanced Rectal Cancer.
abstract: OBJECTIVE
  The objective of this study was to explore the relationship between the circulating lymphocyte level during preoperative chemoradiotherapy (CRT) and pathologic complete response (pCR) in locally advanced rectal cancer.
  
  
  METHODS
  From May 2010 to May 2013, 52 patients treated with preoperative CRT followed by surgery, were analysed. Patients received conventional fractionated radiotherapy (50-54 Gy) with fluorouracil-based chemotherapy. Surgical resection was performed at 4 to 8 weeks after the completion of preoperative CRT. Absolute blood lymphocyte counts and their relative percentage in total white blood cell counts were obtained from complete blood count tests performed prior to and after 4, 8, and 12 weeks of CRT. We analysed the association between achieving pCR and change in blood lymphocyte level during CRT, as well as clinical parameters.
  
  
  RESULTS
  Among 52 patients, 14 (26.9%) had evidence of pCR. Sustaining the blood lymphocyte count during CRT (lymphocyte count at 4 weeks/baseline lymphocyte count > 0.35; odds ratio, 8.33; p=0.02) and initial carcinoembryonic antigen < 4.4 ng/mL (odds ratio, 6.71; p=0.03) were significantly associated with pCR in multivariate analyses.
  
  
  CONCLUSIONS
  Sustaining blood lymphocyte count during preoperative CRT was predictive for pCR in rectal cancer. Further studies are warranted to investigate the association between pathologic responses and circulating lymphocyte count with its subpopulation during preoperative CRT.
authors.affiliation: Department of Radiation Oncology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Jaesung
authors.initials: J
authors.lastname: Heo
authors.affiliation: Department of Radiation Oncology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Mison
authors.initials: M
authors.lastname: Chun
authors.affiliation: Department of Radiation Oncology, Ajou University School of Medicine, Suwon, Korea ; Department of Medicine, The University of Arizona, Tucson, AZ, USA ; BIO5 Institute, The University of Arizona, Tucson, AZ, USA ; Leon Levy Cancer Center, The University of Arizona, Tucson, AZ, USA.
authors.forename: O Kyu
authors.initials: OK
authors.lastname: Noh
authors.affiliation: Department of Radiation Oncology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Young-Taek
authors.initials: YT
authors.lastname: Oh
authors.affiliation: Department of Surgery, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Kwang Wook
authors.initials: KW
authors.lastname: Suh
authors.affiliation: Department of Pediatrics, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Jun Eun
authors.initials: JE
authors.lastname: Park
authors.affiliation: Department of Radiation Oncology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Oyeon
authors.initials: O
authors.lastname: Cho
mesh_terms: D000328:Adult; D000368:Aged; D054316:Biomarkers, Pharmacological; D059248:Chemoradiotherapy; D005260:Female; D005472:Fluorouracil / Q000627:therapeutic use; D006801:Humans; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D012004:Rectal Neoplasms / Q000276:immunology* / Q000473:pathology / Q000601:surgery / Q000628:therapy*; D016896:Treatment Outcome
chemical_list: D054316:Biomarkers, Pharmacological; D005472:Fluorouracil
keywords: Chemoradiotherapy; Lymphocyte count; Neoadjuvant therapy; Pathologic complete response; Predictive factor; Rectal neoplasms