title: The significance and the predictive factors of microscopic lymph node metastasis in patients with clinically node negative papillary thyroid cancer: A retrospective cohort study.
abstract: BACKGROUND
  The management of pathological lateral node involvement (pN1b) from papillary thyroid cancer (PTC) are controversial.
  
  
  METHODS
  A consecutive series of 246 patients, diagnosed with clinically node negative (cN0) PTC who had undergone surgery with prophylactic lateral node dissection, and without postoperative radioactive iodine administration from 2001 to 11, were reviewed to clarify the significance of pN1b.
  
  
  RESULTS
  Eighty-five (35%) patients had pN1b disease. One-half and 30% had pN1b in younger (age less than 45) and older patients (age 45 or over), respectively. Tumor size (≥ 21 mm) could predict pN1b disease in older patients. Patients with pN1b disease recurred more frequently (9 cases, 10.6%) than those without (4 cases, 2.4%), and 2 cases with pN1b died of the disease.
  
  
  CONCLUSIONS
  pN1b disease was commonly found in patients with PTC even when they were diagnosed clinically as node negative. pN1b disease with prognostic meaning was often found in the older patients with larger PTC indicating the necessity for adjuvant treatments.
authors.affiliation: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, Japan. Electronic address: s-noda@med.osaka-cu.ac.jp.
authors.forename: Satoru
authors.initials: S
authors.lastname: Noda
authors.affiliation: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, Japan.
authors.forename: Naoyoshi
authors.initials: N
authors.lastname: Onoda
authors.affiliation: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, Japan.
authors.forename: Tamami
authors.initials: T
authors.lastname: Morisaki
authors.affiliation: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, Japan.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Kashiwagi
authors.affiliation: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Takashima
authors.affiliation: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, Japan.
authors.forename: Kosei
authors.initials: K
authors.lastname: Hirakawa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000473:pathology* / Q000601:surgery* / Q000628:therapy; D002291:Carcinoma, Papillary; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D037981:Neck Dissection; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000473:pathology* / Q000601:surgery* / Q000628:therapy; D013965:Thyroidectomy
keywords: Microscopic node metastasis; Predictive factor; Thyroid cancer