title: Circulating tumor cells in metastatic colorectal cancer: do we need an alternative cutoff?
abstract: OBJECTIVE
  To assess the prognostic and predictive value of circulating tumor cells (CTCs) in metastatic colorectal cancer (mCRC) irrespective of detection level.
  
  
  METHODS
  We evaluated the prognostic and predictive significance of CTC count at baseline and under treatment in 119 mCRC subjects and compared the standard cutoff (≥3 CTCs/7.5 mL to ≥1 CTCs/7.5 mL).
  
  
  RESULTS
  An overall comparison was made between patients with 0, 1-2 and ≥3 CTC (median PFS 8, 4 and 5 months, respectively). Two poor prognostic groups were found, including patients with ≥1 CTCs before and during treatment and patients with 0 CTC at baseline who converted to ≥1 CTCs (p = 0.014).
  
  
  CONCLUSIONS
  The presence of at least 1 CTC at baseline count is predictive for poor prognosis in mCRC patients. Patients with 1-2 CTC should be switched from the favorable prognostic group--conventionally defined by the presence of <3 CTC--to the unfavorable, deserving a more careful monitoring.
authors.affiliation: Department of Molecular Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00141 Rome, Italy. paola.gazzaniga@uniroma1.it
authors.forename: P
authors.initials: P
authors.lastname: Gazzaniga
authors.forename: C
authors.initials: C
authors.lastname: Raimondi
authors.forename: A
authors.initials: A
authors.lastname: Gradilone
authors.forename: G
authors.initials: G
authors.lastname: Biondi Zoccai
authors.forename: C
authors.initials: C
authors.lastname: Nicolazzo
authors.forename: O
authors.initials: O
authors.lastname: Gandini
authors.forename: F
authors.initials: F
authors.lastname: Longo
authors.forename: S
authors.initials: S
authors.lastname: Tomao
authors.forename: G
authors.initials: G
authors.lastname: Lo Russo
authors.forename: P
authors.initials: P
authors.lastname: Seminara
authors.forename: B
authors.initials: B
authors.lastname: Vincenzi
authors.forename: I
authors.initials: I
authors.lastname: Chimenti
authors.forename: M
authors.initials: M
authors.lastname: Cristofanilli
authors.forename: L
authors.initials: L
authors.lastname: Frati
authors.forename: E
authors.initials: E
authors.lastname: Cortesi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000097:blood* / Q000401:mortality / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009360:Neoplastic Cells, Circulating / Q000473:pathology*; D011237:Predictive Value of Tests; D011379:Prognosis; D012016:Reference Values; D012189:Retrospective Studies