title: Prognostic relevance of occult metastases detected by cytokeratin 20 and mucin 2 mRNA levels in sentinel lymph nodes from colon cancer patients.
abstract: OBJECTIVE
  To investigate the prognostic value of occult metastases detected by quantitative measurements of candidate biomarkers in sentinel lymph nodes (SLNs) from patients curatively resected for colon cancer.
  
  
  METHODS
  Resection specimens from consecutive patients undergoing surgery for localized colon cancer were subjected to ex vivo SLN mapping. SLNs were examined for the presence of metastases by routine hematoxylin-erythrosin-safranin staining and by cytokeratin 20 (CK20) and mucin 2 (MUC2) mRNA quantification. The patients were stratified according to KRAS and BRAF mutation status and microsatellite instability status in their primary tumors. Survival end points were analyzed by Kaplan-Meier survival estimates and log-rank tests.
  
  
  RESULTS
  A total of 817 SLNs were identified in 206 (97 %) of the 213 included patients. Routine histological examination of SLNs and other regional lymph nodes identified 63 patients with positive nodes (pN+), of which 42 (67 %) were positive in one or more SLNs (sensitivity 67 %, false-negative rate 33 %). On the basis of the CK20 and MUC2 mRNA levels in SLNs, occult metastases were suggested in 86 (60 %) and 52 (36 %) of the 143 otherwise LN-negative (pN0) patients, respectively. Survival analysis with a median 3.6-year follow-up revealed that MUC2 mRNA quantification had significant prognostic value in SLNs from all patients; however, occult SLN metastasis detection did not.
  
  
  CONCLUSIONS
  Occult SLN metastases detected by CK20 and MUC2 mRNA quantification had limited prognostic value.
authors: Department of Hematology and Oncology, Stavanger University Hospital, Stavanger, Norway. nood@sus.no
authors: Oddmund
authors: O
authors: Nordgård
authors: Satu
authors: S
authors: Oltedal
authors: Ole Gunnar
authors: OG
authors: Aasprong
authors: Jon Arne
authors: JA
authors: Søreide
authors: Kjetil
authors: K
authors: Søreide
authors: Kjersti
authors: K
authors: Tjensvoll
authors: Bjørnar
authors: B
authors: Gilje
authors: Reino
authors: R
authors: Heikkilä
authors: Marianne
authors: M
authors: Guriby
authors: Ragnhild A
authors: RA
authors: Lothe
authors: Rune
authors: R
authors: Smaaland
authors: Hartwig
authors: H
authors: Kørner
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics*; D003110:Colonic Neoplasms / Q000235:genetics / Q000401:mortality / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053554:Keratin-20 / Q000235:genetics*; D008207:Lymphatic Metastasis; D008297:Male; D053842:Microsatellite Instability; D008875:Middle Aged; D055262:Mucin-2 / Q000235:genetics*; D009154:Mutation / Q000235:genetics; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D011518:Proto-Oncogene Proteins / Q000235:genetics; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics; D016283:Proto-Oncogene Proteins p21(ras); D021701:Sentinel Lymph Node Biopsy; D015996:Survival Rate; D055815:Young Adult; D018631:ras Proteins / Q000235:genetics
chemical_list: D014408:Biomarkers, Tumor; C117307:KRAS protein, human; D053554:Keratin-20; C524625:MUC2 protein, human; D055262:Mucin-2; D011518:Proto-Oncogene Proteins; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins