1. In the fifth year of followup, 8 of 12 original patients thyroidectomized for MTC, diagnosed solely by abnormal
calcitonin values, are disease free by all criteria. Elevated
calcitonin levels are the only manifestation of active disease in three patients with presumed
metastases. 2. Routine annual screening of susceptible individuals is a practical measure and has in 6 cases detected the premalignant condition of G-cell
hyperplasia and in 1 patient a premetastatic state of MTC. It is premature to conclude that yearly screening is sufficient to detect all cases of premetastatic disease and for this reason we are recommending a yearly screen with
pentagastrin and
calcium tests and the more convenient
pentagastrin test at 6 month intervals for those in the high-risk age group between 8 and 18. If screening at such intervals proves to be ineffective in preventing the disease in every case, consideration must be given to prophylactic
thyroidectomy although we are not currently recommending this precedure. 3.
Pentagastrin injection is often a more effective
secretagogue for
calcitonin than is
calcium infusion, but this is not uniformly true. We therefore recommend use of both tests as the most appropriate screening procedure. 4.
Epinephrine is a major secretory product of
pheochromocytomas in the J-kindred and sequential E/N ratios may be of use in the early detection of
pheochromocytoma in other kindreds. 5. Adrenal medullary
hyperplasia has been found in 3 adrenal glands and is probably a
preneoplastic condition analogous to C-cell
hyperplasia.