title: Biopathologic features and clinical significance of micrometatasis in the lymph node of early gastric cancer.
abstract: OBJECTIVE
  To evaluate the biopathologic features and clinical significance of nodal micrometastasis (MI) in early gastric cancer (EGC).
  
  
  METHODS
  Among 1022 EGC patients who underwent gastrectomy with lymphadenectomy of D1 + β or more from March 2001 to December 2005 at the Korean National Cancer Center, available nodal metastasis was found in 90 pT1N1 patients. Nodal metastasis was confirmed by immunohistochemistry (IHC) with cytokeratin and patients were classified into MI and macrometastasis (MA) groups based on the main tumor burden according to the 6(th) International Union Against Cancer/American Joint Committee on Cancer staging system; the main tumor burden with a diameter of greater than 0.2 mm but no greater than 2 mm as MI, and greater than 2 mm as MA of the representative metastatic node. Proliferative and apoptotic activities of the primary tumor and the nodal metastasis were measured by IHC with Ki-67 and terminal deoxynucleotidyl transferase dUTP nick end labeling, respectively. Biopathologic and clinical features of the patients were analyzed and compared between MI and MA groups. Patients with recurrence were compared with those without recurrence to identify risk factors for recurrence.
  
  
  RESULTS
  Thirty-seven patients showed MI and the other 53 patients revealed MA in the lymph node; the incidence of patients with MI and MA was 41.1% and 58.9%. The main tumor burden was 0.9 and 4.6 mm in the representative metastatic node, respectively. Japanese N2 stations were more frequently involved in MA group (20.9%) than in MI group (10.3%) but the difference was not statistically different (P = 0.338). Proliferative and apoptotic activities of MI were decreased than those of MA (26.7% vs 40.5%, P = 0.004 and 1.0% vs 3.0%, P < 0.001, respectively). However, nodal MI in the current study showed a relatively high proliferative activity and an equivalent apoptotic activity compared to other cancers in the previously published studies. Recurrence was observed in 6 patients during the mean follow up period of 87.6 ± 26.2 mo. The recurrence was significantly associated with the presence of MA (P = 0.041) and lymphovascular invasion of the primary tumor (P = 0.032).
  
  
  CONCLUSIONS
  Lymphadenectomy of D1 + β or more might be necessary in patients with MI in sentinel node to prevent recurrence by clearing MI involving Japanese N2 station.
authors.affiliation: Min Jung Jo, Ji Yeon Park, Myeong-Cherl Kook, Keun Won Ryu, Soo-Jeong Cho, Jun Ho Lee, Il Ju Choi, Young-Woo Kim, Gastric Cancer Branch, Research Institute and Hospital, National Cancer Center, Goyang-si 410-769, South Korea.
authors.forename: Min Jung
authors.initials: MJ
authors.lastname: Jo
authors.affiliation: Min Jung Jo, Ji Yeon Park, Myeong-Cherl Kook, Keun Won Ryu, Soo-Jeong Cho, Jun Ho Lee, Il Ju Choi, Young-Woo Kim, Gastric Cancer Branch, Research Institute and Hospital, National Cancer Center, Goyang-si 410-769, South Korea.
authors.forename: Ji Yeon
authors.initials: JY
authors.lastname: Park
authors.affiliation: Min Jung Jo, Ji Yeon Park, Myeong-Cherl Kook, Keun Won Ryu, Soo-Jeong Cho, Jun Ho Lee, Il Ju Choi, Young-Woo Kim, Gastric Cancer Branch, Research Institute and Hospital, National Cancer Center, Goyang-si 410-769, South Korea.
authors.forename: Joon Seon
authors.initials: JS
authors.lastname: Song
authors.affiliation: Min Jung Jo, Ji Yeon Park, Myeong-Cherl Kook, Keun Won Ryu, Soo-Jeong Cho, Jun Ho Lee, Il Ju Choi, Young-Woo Kim, Gastric Cancer Branch, Research Institute and Hospital, National Cancer Center, Goyang-si 410-769, South Korea.
authors.forename: Myeong-Cherl
authors.initials: MC
authors.lastname: Kook
authors.affiliation: Min Jung Jo, Ji Yeon Park, Myeong-Cherl Kook, Keun Won Ryu, Soo-Jeong Cho, Jun Ho Lee, Il Ju Choi, Young-Woo Kim, Gastric Cancer Branch, Research Institute and Hospital, National Cancer Center, Goyang-si 410-769, South Korea.
authors.forename: Keun Won
authors.initials: KW
authors.lastname: Ryu
authors.affiliation: Min Jung Jo, Ji Yeon Park, Myeong-Cherl Kook, Keun Won Ryu, Soo-Jeong Cho, Jun Ho Lee, Il Ju Choi, Young-Woo Kim, Gastric Cancer Branch, Research Institute and Hospital, National Cancer Center, Goyang-si 410-769, South Korea.
authors.forename: Soo-Jeong
authors.initials: SJ
authors.lastname: Cho
authors.affiliation: Min Jung Jo, Ji Yeon Park, Myeong-Cherl Kook, Keun Won Ryu, Soo-Jeong Cho, Jun Ho Lee, Il Ju Choi, Young-Woo Kim, Gastric Cancer Branch, Research Institute and Hospital, National Cancer Center, Goyang-si 410-769, South Korea.
authors.forename: Jun Ho
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Min Jung Jo, Ji Yeon Park, Myeong-Cherl Kook, Keun Won Ryu, Soo-Jeong Cho, Jun Ho Lee, Il Ju Choi, Young-Woo Kim, Gastric Cancer Branch, Research Institute and Hospital, National Cancer Center, Goyang-si 410-769, South Korea.
authors.forename: Byung-Ho
authors.initials: BH
authors.lastname: Nam
authors.affiliation: Min Jung Jo, Ji Yeon Park, Myeong-Cherl Kook, Keun Won Ryu, Soo-Jeong Cho, Jun Ho Lee, Il Ju Choi, Young-Woo Kim, Gastric Cancer Branch, Research Institute and Hospital, National Cancer Center, Goyang-si 410-769, South Korea.
authors.forename: Eun Kyung
authors.initials: EK
authors.lastname: Hong
authors.affiliation: Min Jung Jo, Ji Yeon Park, Myeong-Cherl Kook, Keun Won Ryu, Soo-Jeong Cho, Jun Ho Lee, Il Ju Choi, Young-Woo Kim, Gastric Cancer Branch, Research Institute and Hospital, National Cancer Center, Goyang-si 410-769, South Korea.
authors.forename: Il Ju
authors.initials: IJ
authors.lastname: Choi
authors.affiliation: Min Jung Jo, Ji Yeon Park, Myeong-Cherl Kook, Keun Won Ryu, Soo-Jeong Cho, Jun Ho Lee, Il Ju Choi, Young-Woo Kim, Gastric Cancer Branch, Research Institute and Hospital, National Cancer Center, Goyang-si 410-769, South Korea.
authors.forename: Young-Woo
authors.initials: YW
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D017209:Apoptosis; D014408:Biomarkers, Tumor / Q000032:analysis; D001706:Biopsy; D049109:Cell Proliferation; D017024:Chemotherapy, Adjuvant; D055088:Early Detection of Cancer / Q000379:methods; D005260:Female; D005743:Gastrectomy; D006801:Humans; D007150:Immunohistochemistry; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D061206:Neoplasm Micrometastasis; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D056910:Republic of Korea; D012189:Retrospective Studies; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor
keywords: Early gastric cancer; Lymphadenectomy; Macrometastasis; Micrometastasis; Sentinel node biopsy