title: Association of GUCY2C expression in lymph nodes with time to recurrence and disease-free survival in pN0 colorectal cancer.
abstract: BACKGROUND
  The established relationship between lymph node metastasis and prognosis in colorectal cancer suggests that recurrence in 25% of patients with lymph nodes free of tumor cells by histopathology (pN0) reflects the presence of occult metastases. Guanylyl cyclase 2C (GUCY2C) is a marker expressed by colorectal tumors that could reveal occult metastases in lymph nodes and better estimate recurrence risk.
  
  
  OBJECTIVE
  To examine the association of occult lymph node metastases detected by quantifying GUCY2C messenger RNA, using the reverse transcriptase-polymerase chain reaction, with recurrence and survival in patients with colorectal cancer.
  
  
  METHODS
  Prospective study of 257 patients with pN0 colorectal cancer enrolled between March 2002 and June 2007 at 9 US and Canadian centers (7 academic medical centers and 2 community hospitals) provided 2570 fresh lymph nodes measuring 5 mm or larger for histopathology and GUCY2C messenger RNA analysis. Patients were followed up for a median of 24 months (range, 2-63 months) for disease recurrence or death.
  
  
  METHODS
  Time to recurrence (primary outcome) and disease-free survival (secondary outcome) relative to expression of GUCY2C in lymph nodes.
  
  
  RESULTS
  Thirty-two patients (12.5%) had lymph nodes negative for GUCY2C (pN0 [mol-]), and all but 2 remained free of disease during follow-up (recurrence rate, 6.3%; 95% confidence interval [CI], 0.8%-20.8%). Conversely, 225 patients (87.5%) had lymph nodes positive for GUCY2C (pN0 [mol+]), and 47 developed recurrent disease (20.9%; 95% CI, 15.8%-26.8%) (P = .006). Multivariate analyses revealed that GUCY2C in lymph nodes was an independent marker of prognosis. Patients who were pN0 (mol+) exhibited earlier time to recurrence (adjusted hazard ratio, 4.66; 95% CI, 1.11-19.57; P = .04) and reduced disease-free survival (adjusted hazard ratio, 3.27; 95% CI, 1.15-9.29; P = .03).
  
  
  CONCLUSIONS
  Expression of GUCY2C in histologically negative lymph nodes appears to be independently associated with time to recurrence and disease-free survival in patients with pN0 colorectal cancer.
authors.affiliation: Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, 132 S 10th St, Philadelphia, PA 19107, USA. Scott.Waldman@jefferson.edu
authors.forename: Scott A
authors.initials: SA
authors.lastname: Waldman
authors.forename: Terry
authors.initials: T
authors.lastname: Hyslop
authors.forename: Stephanie
authors.initials: S
authors.lastname: Schulz
authors.forename: Alan
authors.initials: A
authors.lastname: Barkun
authors.forename: Karl
authors.initials: K
authors.lastname: Nielsen
authors.forename: Janis
authors.initials: J
authors.lastname: Haaf
authors.forename: Christine
authors.initials: C
authors.lastname: Bonaccorso
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Li
authors.forename: David S
authors.initials: DS
authors.lastname: Weinberg
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis / Q000378:metabolism*; D015179:Colorectal Neoplasms / Q000201:enzymology*; D018572:Disease-Free Survival; D005260:Female; D006162:Guanylate Cyclase / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008198:Lymph Nodes / Q000201:enzymology*; D008207:Lymphatic Metastasis / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D019370:Observation; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012333:RNA, Messenger / Q000032:analysis; D000074261:Receptors, Enterotoxin; D050705:Receptors, Guanylate Cyclase-Coupled; D018000:Receptors, Peptide / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D014408:Biomarkers, Tumor; D012333:RNA, Messenger; D018000:Receptors, Peptide; C000613654:GUCY2C protein, human; D006162:Guanylate Cyclase; D000074261:Receptors, Enterotoxin; D050705:Receptors, Guanylate Cyclase-Coupled