title: A systematic review of primary active surveillance management of low-risk papillary carcinoma.
abstract: OBJECTIVE
  Active surveillance is close follow-up of neoplasms, with predetermined intervention triggers. We systematically reviewed the published English language literature on primary active surveillance of low-risk papillary thyroid cancer (PTC).
  
  
  RESULTS
  We searched seven electronic databases (1980-2015), supplemented with a hand search. Two reviewers independently screened 1715 citations and reviewed 32 full-text papers, ultimately including two papers. Data were independently abstracted. There were two Japanese single-center, single-arm studies reporting on 1235 and 322 patients with PTC microcarcinoma (primary ≤1 cm in diameter) confined to the thyroid. Mean study follow-up was of 5.0 and 6.5 years, respectively. Disease triggers for thyroidectomy included progression of the primary tumor or incident metastatic disease. The rates of thyroidectomy were 15.5% (191/1235) and 8.7% (28/322) in respective studies. The incidence of primary tumor enlargement ≥3 mm in maximal diameter was 4.6% (58/1235) and 5.0% (16/322). The incidence of nodal metastases was 1.5% (19/1235) and 0.9% (3/322). There were neither reports of PTC-related death nor development of distant metastatic disease. Quality of life, psychosocial health, and economic outcomes were not reported.
  
  
  CONCLUSIONS
  In two Japanese single-arm studies, active surveillance of PTC microcarcinoma was relatively well tolerated; however, more long-term outcome research is needed.
authors.affiliation: aDepartment of Medicine, Division of Endocrinology, University of Toronto bDepartment of Otolaryngology Head and Neck Surgery, University Health Network and University of Toronto cDepartment of Medicine, Division of Endocrinology, University Health Network, Toronto, Ontario, Canada.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Alhashemi
authors.forename: David P
authors.initials: DP
authors.lastname: Goldstein
authors.forename: Anna M
authors.initials: AM
authors.lastname: Sawka
mesh_terms: D002277:Carcinoma / Q000473:pathology* / Q000628:therapy; D002291:Carcinoma, Papillary / Q000473:pathology / Q000628:therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000473:pathology* / Q000628:therapy; D013965:Thyroidectomy / Q000706:statistics & numerical data