title: Circulating tumor cells: A promising marker of predicting tumor response in rectal cancer patients receiving neoadjuvant chemo-radiation therapy.
abstract: OBJECTIVE
  The aim of this study was to investigate the role of circulating tumor cells (CTCs) in assessing and predicting tumor response to neoadjuvant chemoradiotherapy (CRT) for patients with locally advanced rectal cancer (LARC).
  
  
  METHODS
  A total of 115 patients with T3-4 and/or N+ rectal cancer were enrolled. All patients received neoadjuvant CRT followed by radical surgery after 6-8 weeks. The pathological results after surgery were evaluated according to tumor regression grade (TRG) classification.
  
  
  RESULTS
  Based on TRG score, patients were classified as responders (TRG3-4) and non-responders (TRG0-2). The baseline CTC counts of responders were significantly higher than those of non-responders (44.50±11.94 vs. 37.67±15.45, P=0.012). By contrast, the post-CRT CTC counts of responders were significantly lower than those of non-responders (3.61±2.90 vs. 12.08±7.40, P<0.001). According to ROC analysis, Δ%CTC (percentage difference in CTC counts between baseline and post-CRT) was identified as the stronger predictor to discriminate responders from non-responders (AUC: 0.860). The results of multivariate analysis also indicated that post-CRT CTC counts and Δ%CTC were significantly and independently associated with tumor response to CRT.
  
  
  CONCLUSIONS
  The detection of CTCs is a powerful and promising tool for evaluating and predicting responses to neoadjuvant CRT in LARC patients.
authors.affiliation: Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, China.|Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China.
authors.forename: Wenjie
authors.initials: W
authors.lastname: Sun
authors.affiliation: Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, China.|Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China.
authors.forename: Guichao
authors.initials: G
authors.lastname: Li
authors.affiliation: Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, China.|Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China.
authors.forename: Juefeng
authors.initials: J
authors.lastname: Wan
authors.affiliation: Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, China.|Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China.
authors.forename: Ji
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China.|Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai 200032, China.
authors.forename: Weiqi
authors.initials: W
authors.lastname: Shen
authors.affiliation: Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, China.|Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059248:Chemoradiotherapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D020360:Neoadjuvant Therapy; D009360:Neoplastic Cells, Circulating / Q000187:drug effects* / Q000528:radiation effects*; D011379:Prognosis; D012372:ROC Curve; D012004:Rectal Neoplasms / Q000097:blood* / Q000175:diagnosis / Q000628:therapy*; D016896:Treatment Outcome; D055815:Young Adult
keywords: circulating tumor cells; neoadjuvant chemo-radiation therapy; prediction; rectal cancer