title: Detection of lymphatic micrometastases in patients with stages I and II colorectal cancer: impact on five-year survival.
abstract: OBJECTIVE
  Despite having removed the whole macroscopic disease (curative intent surgery), one of five patients with Stages I and II colorectal cancer will develop recurrence. Lymphatic micrometastases detected by immunohistochemistry could be one of explanation for recurrence and cancer-related death in patients without lymph node involvement at light microscopy. However, the biologic importance of micrometastases remains unclear. This study was designed to determine the impact of micrometastases in five-year survival in patients with Stages I and II colorectal cancer.
  
  
  METHODS
  This retrospective study included patients operated on between May 1989 and January 1999 for colorectal cancer without histopathologic lymph node involvement. Patients who received any adjuvant therapy were excluded. Immunohistochemical staining of the lymph nodes was performed with antipancytokeratin antibodies. Follow-up data were obtained from the clinical database and death certificates. Survival was estimated by the Kaplan-Meier method and compared by the log-rank test.
  
  
  RESULTS
  Micrometastases were observed in 26 of 90 patients (28.9 percent). The mean follow-up time was 90.7 (range, 11-160) months. Seventeen cancer-related deaths occurred during follow-up (18.9 percent), 6 of them in patients with micrometastases (23.1 percent) and 11 in patients without micrometastases (17.2 percent; P = 0.559). Cancer-specific five-year survival was 87 percent in the whole group and 81 percent in patients positive for micrometastases vs. 90 percent in negative patients ( P = 0.489).
  
  
  CONCLUSIONS
  The presence of micrometastases in patients with Stages I and II colorectal cancer seems not to have any impact on cancer-specific survival.
authors.affiliation: Department of Digestive Surgery, Faculty of Medicine, Catholic University of Chile, Santiago, Chile.
authors.forename: Udo
authors.initials: U
authors.lastname: Kronberg
authors.forename: Francisco
authors.initials: F
authors.lastname: López-Kostner
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Soto
authors.forename: Alvaro
authors.initials: A
authors.lastname: Zúñiga
authors.forename: Ignacio
authors.initials: I
authors.lastname: Wistuba
authors.forename: Vanessa
authors.initials: V
authors.lastname: Miranda
authors.forename: Eliana
authors.initials: E
authors.lastname: Pinto
authors.forename: Paola
authors.initials: P
authors.lastname: Viviani
authors.forename: Guillermo
authors.initials: G
authors.lastname: Marshall
mesh_terms: D000368:Aged; D015179:Colorectal Neoplasms / Q000401:mortality* / Q000473:pathology*; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology*; D009367:Neoplasm Staging; D012189:Retrospective Studies; D016019:Survival Analysis