A ten-year clinical update of a large RET p.Gly533Cys kindred with medullary thyroid carcinoma emphasizes the need for an individualized assessment of affected relatives

Clin Endocrinol (Oxf). 2014 Feb;80(2):235-45. doi: 10.1111/cen.12264. Epub 2013 Jun 28.

Abstract

Objective: Reviewing the clinical outcomes of a large kindred with a RET p.Gly533Cys mutation, 10 years after the first description of this kindred, has provided an important set of clinical data for healthcare decision-making.

Design and patients: We identified 728 RET533 Brazilian relatives, spread out over 7 generations. We performed clinical examination, biochemical and imaging analyses in the proband and in 103 carriers.

Measurement and results: The proband has been followed without evidence of structural disease in the last 10 years but with elevated calcitonin. The clinical and surgical features of 60 thyroidectomized RET533 relatives were also described. Forty-six patients had MTC (21-72 years), and 11 patients had C-cell hyperplasia (CCH) (5-42 years). Twelve MTC patients with lymph node metastases had a tumour size of 0·7-2·8 cm. Calcitonin level and CEA were correlated with disease stage, and none of the patients presented with an altered PTH or metanephrine. A 63-year-old woman developed pheochromocytoma and breast cancer. Two other RET533 relatives developed lung squamous cell carcinoma and melanoma.

Conclusions: A vast clinical variability in RET533 presentation was observed, ranging from only an elevated calcitonin level (3%) to local metastatic disease (25%). Many individuals were cured (42%) and the majority had controlled chronic disease (56%), reinforcing the need for individualized ongoing risk stratification assessment. The importance of this update relies on the fact that it allows us to delineate the natural history of RET 533 MEN2A 10 years after its first description.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Amino Acid Substitution
  • Calcitonin / blood
  • Carcinoembryonic Antigen / blood
  • Carcinoma, Neuroendocrine
  • Child
  • Child, Preschool
  • Cysteine / genetics
  • Family Health
  • Female
  • Follow-Up Studies
  • Glycine / genetics
  • Humans
  • Male
  • Metanephrine / urine
  • Middle Aged
  • Multiple Endocrine Neoplasia Type 2a / genetics*
  • Multiple Endocrine Neoplasia Type 2a / surgery
  • Mutation*
  • Pedigree
  • Proto-Oncogene Proteins c-ret / genetics*
  • Thyroid Neoplasms / genetics*
  • Thyroid Neoplasms / surgery
  • Thyroidectomy
  • Time Factors
  • Young Adult

Substances

  • Carcinoembryonic Antigen
  • Metanephrine
  • Calcitonin
  • Proto-Oncogene Proteins c-ret
  • Cysteine
  • Glycine

Supplementary concepts

  • Thyroid cancer, medullary