title: Risk-adapted management of papillary thyroid carcinoma according to our own risk group classification system: is thyroid lobectomy the treatment of choice for low-risk patients?
abstract: BACKGROUND
  Our original system for risk group classification for predicting cause-specific death from papillary thyroid carcinoma (PTC) defined patients with distant metastasis and older patients (≥ 50 years) with either massive extrathyroidal extension or large (≥ 3 cm) lymph node metastasis as high risk; all others are low risk. For unilateral, low-risk PTC, the extent of thyroidectomy (less-than-total thyroidectomy vs total or near-total thyroidectomy) has been determined based on the choice of the patient since 2005.
  
  
  METHODS
  Of 1,187 patients who underwent initial thyroidectomy for PTC (tumor size [T] >1 cm) between 1993 and 2010, 967 (82%) were classified as low risk. Among low-risk patients, 791 (82%) underwent less than total thyroidectomy.
  
  
  RESULTS
  The 10-year cause-specific survival and disease-free survival rates did not differ between patients who underwent total thyroidectomy versus less than total thyroidectomy (cause-specific survival, 99% vs 99% [P = .61]; disease-free survival, 91% vs 87% [P = .90]). Age ≥ 60 years, T ≥ 3 cm, and lymph node metastases >3 cm represented significant risk factors for distant recurrence.
  
  
  CONCLUSIONS
  The favorable overall survival of low-risk patients, regardless of the extent of thyroidectomy, supports patient autonomy in treatment-related decision making. Low-risk patients possessing risk factors for distant recurrence would be likely to benefit from total thyroidectomy followed by radioactive iodine.
authors.affiliation: Division of Head and Neck, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Aya
authors.initials: A
authors.lastname: Ebina
authors.affiliation: Division of Head and Neck, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan; Division of Endocrine Surgery, Department of Surgery, Nippon Medical School, Tokyo, Japan. Electronic address: isugitani@jfcr.or.jp.
authors.forename: Iwao
authors.initials: I
authors.lastname: Sugitani
authors.affiliation: Division of Head and Neck, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Fujimoto
authors.affiliation: Division of Ultrasonography Examination, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Yamada
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D002277:Carcinoma / Q000145:classification / Q000401:mortality* / Q000601:surgery*; D002291:Carcinoma, Papillary; D015331:Cohort Studies; D003657:Decision Making; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness / Q000473:pathology; D009367:Neoplasm Staging; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012308:Risk Management; D016019:Survival Analysis; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000145:classification / Q000401:mortality* / Q000601:surgery*; D013965:Thyroidectomy / Q000379:methods* / Q000401:mortality; D016896:Treatment Outcome; D055815:Young Adult