title: Selective surgery and adjuvant therapy based on risk classifications of well-differentiated thyroid cancer.
abstract: BACKGROUND
  The prognosis of well-differentiated thyroid cancer has been stratified into low- and high-risk groups. These risk groups can be used to predict prognosis and to guide treatment.
  
  
  METHODS
  Retrospective study of 962 patients with well-differentiated thyroid cancer treated from 1940 to 1998. Stratification into low- and high-risk groups based on age, metastases, extent, and size (AMES). Effects on survival of surgery, lymph node dissection, and radiation therapy were examined.
  
  
  RESULTS
  Seven hundred twenty-eight cases were papillary and 234 were follicular carcinoma. Seven hundred-fifty cases were low risk and 207 high risk. Twenty-year survival was 97.4% in the low-risk patients and 54.0% in high-risk patients (P < 0.001); it was 63.2% in the younger high-risk group and 41.0% in the older high-risk group (P < 0.001). Older high-risk patients had a survival advantage with bilateral thyroidectomy. Extent of surgery did not change survival in either the younger high-risk group or the low-risk group. Lymph node dissection and radioactive iodine ablation did not have an impact on survival.
  
  
  CONCLUSIONS
  Well-differentiated thyroid cancer in low-risk patients has a favorable outcome regardless of treatment. Low-risk patients can be safely treated with unilateral thyroidectomy alone. Risk stratification with a modification of the AMES criteria can be used to guide treatment.
authors.affiliation: Lahey Clinic, Burlington, Massachusetts 01803, USA.
authors.forename: S
authors.initials: S
authors.lastname: Cross
authors.forename: J P
authors.initials: JP
authors.lastname: Wei
authors.forename: S
authors.initials: S
authors.lastname: Kim
authors.forename: D M
authors.initials: DM
authors.lastname: Brams
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000401:mortality / Q000601:surgery*; D000231:Adenocarcinoma, Papillary / Q000401:mortality / Q000601:surgery*; D000367:Age Factors; D018572:Disease-Free Survival; D017558:Elective Surgical Procedures; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008197:Lymph Node Excision; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D013964:Thyroid Neoplasms / Q000401:mortality / Q000601:surgery*; D013965:Thyroidectomy / Q000379:methods*
chemical_list: D007457:Iodine Radioisotopes