title: The Prevalence of Overall and Initial Lymph Node Metastases in Clinical T1N0 Thoracic Esophageal Cancer: From the Results of JCOG0502, a Prospective Multicenter Study.
abstract: OBJECTIVE
  To evaluate the sites and frequencies of overall and initial lymph node (LN) metastases (LNMs) of clinical T1N0 esophageal cancer.
  
  
  BACKGROUND
  The sites and frequencies of initial LNMs and sentinel LNs (SLNs) of esophageal cancer remain unclear.
  
  
  METHODS
  The Japan Clinical Oncology Group JCOG0502 trial was a 4-arm prospective study that compared esophagectomy with chemoradiotherapy for clinical T1N0 esophageal cancer in both randomized and patient-preference arms. The preoperative diagnostic accuracy was evaluated for patients assigned to the surgery arm. Patients who withdrew consent and who were not treated were excluded. All patients underwent esophagectomy with D2 or greater LN dissection. From the pathologic findings, sites and frequencies of LNMs and SLNs were assessed and the frequency of skip LNMs was calculated.
  
  
  RESULTS
  In total, 211 patients underwent LNM and SLN analysis. Regarding N-factor accuracy, 57 (27.0%) of 211 clinical N0 cases had pathologic LNMs. The upper mediastinal and mediastinal/abdominal regions were frequent sites of LNMs in upper and lower thoracic cases, respectively. However, in middle thoracic cases, LNMs were observed in the neck, mediastinal, and abdominal regions, and pathologic SLN spread to all 3 fields. The frequency of skip LNMs was 36.7%.
  
  
  CONCLUSIONS
  A clinical diagnosis of T1N0 is not sufficiently accurate, and therefore, it is unacceptable to omit LN dissection or minimize the prophylactic radiation field. SLNs, which are not location restricted, should be surveyed in all 3 fields.
authors.affiliation: *Department of Frontier Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan†Gastrointestinal Medical Oncology Division, National Cancer Center Hospital, Tokyo, Japan‡Esophageal Surgery Division, National Cancer Center Hospital, Tokyo, Japan§Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan¶Department of Surgery, National Hospital Organization Shikoku Cancer Center, Matsuyama, Japan||Esophageal Surgery Division, National Cancer Center Hospital East, Kashiwa, Japan**Department of Surgery, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan††Gastroenterological Surgery, Toranomon Hospital, Tokyo, Japan‡‡Department of Surgery, Niigata Cancer Center Hospital, Niigata, Japan§§Department of Surgery, Shizuoka General Hospital, Shizuoka, Japan¶¶Japan Clinical Oncology Group Data Center, National Cancer Center, Tokyo, Japan||||Department of Surgery, Keio University, School of Medicine, Tokyo, Japan.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Akutsu
authors.forename: Ken
authors.initials: K
authors.lastname: Kato
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Igaki
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Ito
authors.forename: Isao
authors.initials: I
authors.lastname: Nozaki
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Daiko
authors.forename: Masahiko
authors.initials: M
authors.lastname: Yano
authors.forename: Harushi
authors.initials: H
authors.lastname: Udagawa
authors.forename: Satoru
authors.initials: S
authors.lastname: Nakagawa
authors.forename: Masakazu
authors.initials: M
authors.lastname: Takagi
authors.forename: Junki
authors.initials: J
authors.lastname: Mizusawa
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kitagawa
mesh_terms: D000328:Adult; D000368:Aged; D059248:Chemoradiotherapy; D004938:Esophageal Neoplasms / Q000473:pathology* / Q000628:therapy*; D016629:Esophagectomy; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008207:Lymphatic Metastasis / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D015995:Prevalence; D011446:Prospective Studies; D016019:Survival Analysis