Spontaneous remission in thyroid cancer patients after biochemical incomplete response to initial therapy

Clin Endocrinol (Oxf). 2012 Jul;77(1):132-8. doi: 10.1111/j.1365-2265.2012.04342.x.


Objective: To validate the American Thyroid Association (ATA) initial risk of recurrence scheme and the Memorial Sloan Kettering Cancer Center (MSKCC) response to therapy re-stratification approach in a large cohort of patients with differentiated thyroid cancer (DTC) treated outside of the United States.

Design: Retrospective chart review.

Patients: Five hundred and six patients with DTC followed for a median of 10 years after total thyroidectomy and RAI remnant ablation at a major cancer centre in Brazil.

Measurements: Final clinical outcomes were assessed based on American Joint Cancer Committee (AJCC)/Union Internationale Contre le Cancer (UICC) staging, ATA risk stratification and response to therapy assessment (excellent, acceptable, biochemical incomplete and structural incomplete).

Results: The AJCC/UICC staging system did not adequately stratify patients with regard to the risk of recurrence/persistent disease. However, the ATA system demonstrated a 13% risk of recurrent/persistent disease in low-risk patients, 36% in intermediate risk patients, and 68% in high-risk patients. Furthermore, an excellent response to therapy decreased the risk of recurrent/persistent disease to 1·4%. At the time of final follow-up, 34% of the biochemical incomplete response patients had been re-classified as having no evidence of disease (NED) without having received any additional therapy beyond continue levothyroxine suppression. Conversely, even after additional therapies, only 9% of the patients with an incomplete structural response were eventually re-classified as NED.

Conclusions: These data validate the ATA risk classification as an excellent initial predictor of recurrent/persistent disease and confirm the clinical utility of the MSKCC dynamic risk assessment system in a cohort of patients evaluated and treated outside the United States.

Publication types

  • Evaluation Study
  • Validation Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Biomarkers, Tumor / analysis
  • Biomarkers, Tumor / blood
  • Carcinoma / blood
  • Carcinoma / pathology
  • Carcinoma / therapy*
  • Cohort Studies
  • Female
  • Humans
  • Male
  • Middle Aged
  • Neoadjuvant Therapy
  • Neoplasm Staging / methods
  • Remission, Spontaneous
  • Retrospective Studies
  • Risk Assessment
  • Risk Factors
  • Societies, Medical
  • Thyroid Neoplasms / blood
  • Thyroid Neoplasms / pathology
  • Thyroid Neoplasms / therapy*
  • Treatment Outcome
  • Young Adult


  • Biomarkers, Tumor