Purpose: To determine whether published disease penetrance estimates of 50% for pheochromocytoma and 20-30% for primary hyperparathyroidism in multiple endocrine neoplasia (MEN 2A), conceivably reflecting overrepresentation of index patients with completely developed MEN 2A, may be too high.
Methods: Cross-sectional study of carriers at high risk of MEN 2A from a tertiary referral center.
Results: There were 213 carriers of RET mutations in codon 634, born between 1922 and 2014. Median age of thyroidectomy was 17 years, with MTC being present in 76.5%; pheochromocytoma in 31.0% at a median of 34 years in the first, and in 18.8% at a median of 35 years in the second adrenal; and primary hyperparathyroidism in 10.8% at a median of 39 years. MTC, pheochromocytoma and primary hyperparathyroidism, stratified by year of birth, were diagnosed earlier over time: for MTC from 51 to 4 years; for pheochromocytoma from 51 to 22.5 years in the first, and from 51 to 29.5 years in the second adrenal, and for primary hyperparathyroidism from 46 to 12 years (P ≤ 0.008). This decline in age was paralleled by diminishing tumor diameters, more strongly in the thyroid (from 20 to 1.8 mm; P < 0.001) than in the adrenals (from 43 to 30 mm in the first, and from 20-57.5 to 30.5 mm in the second adrenal; statistically nonsignificant).
Conclusions: The lower disease penetrance estimates and sluggish decline of adrenal tumor diameters call for more widespread adoption of adrenal-sparing and parathyroid preservation surgery based on early and regular biochemical screening.
Keywords: Biochemical screening; Molecular genetic screening; Multiple endocrine neoplasia 2A; Precision medicine; RET proto-oncogene; Serum biomarkers.