Subset analysis of the Japanese risk classification guidelines for papillary thyroid carcinoma

Endocr J. 2020 Mar 28;67(3):275-282. doi: 10.1507/endocrj.EJ19-0387. Epub 2019 Nov 27.


Guidelines published by the Japan Association of Endocrine Surgeons (JAES)/Japanese Society of Thyroid Surgery (JSTS) for patients with papillary thyroid carcinoma describe four risk classes (very low-, low-, intermediate- and high-risk) for deciding on therapeutic strategies. Here, we investigate cause-specific survival (CSS) of high- and intermediate-risk patients, taking their age into consideration. CSS of intermediate-risk patients ≥55 years was poorer than that of those <55 years (p < 0.0001) (20-year CSS rates, 96.9% vs. 98.7%). CSS of intermediate-risk patients <55 years was excellent but still poorer (p = 0.0152) than that of low- or very low-risk patients (20-year CSS rates, 100%). CSS of high-risk patients <55 years (20-year CSS rates, 96.0%) was similar (p = 0.7412) to that of intermediate-risk patients ≥55 years, while high-risk patients ≥55 years (20-year CSS rates, 80.6%) showed much poorer prognosis (p < 0.0001) than the others. In high-risk patients <55 years, distant metastasis (M1), extrathyroid extension (Ex), node metastasis ≥3 cm, and extranodal tumor extension, and in those ≥55 years, M1, Ex, and tumor size >4 cm were regarded as prognostic factors on multivariate analysis. We therefore conclude that 1) prognosis of high-risk patients ≥55 years should be carefully treated because of significantly poor prognosis, 2) prognostic factors of high-risk patients vary according to patient age, and 3) overtreatment of intermediate-risk patients and young high-risk patients should be avoided; however, appropriate treatment strategies need to be established, considering that their prognoses are excellent, but still poorer than low- or very low-risk patients.

Keywords: Age; Extrathyroid extension; Guidelines; Papillary thyroid carcinoma; Prognosis.

MeSH terms

  • Adolescent
  • Adult
  • Age Factors
  • Aged
  • Aged, 80 and over
  • Child
  • Child, Preschool
  • Female
  • Guidelines as Topic
  • Humans
  • Japan
  • Male
  • Middle Aged
  • Prognosis
  • Risk Assessment
  • Risk Factors
  • Thyroid Cancer, Papillary / pathology*
  • Thyroid Cancer, Papillary / surgery
  • Thyroid Gland / pathology*
  • Thyroid Gland / surgery
  • Thyroid Neoplasms / pathology*
  • Thyroid Neoplasms / surgery
  • Thyroidectomy
  • Young Adult