Patients with the familial type of disease tend to have a better prognosis than those with the sporadic form.
Features associated with poor prognosis:
(1) extrathyroid tumor invasion, with extension into cervical soft tissue (patients with capsular invasion without extension into soft tissue have similar prognosis to those with intact capsule)
(2) age > 60 years
(3) distant metastases
(4) absence of amyloid in tumor
(5) aneuploid DNA pattern
(6) tumor diameter > 1 cm
(7) Stage III or IV at time of diagnosis
Features with a high risk of recurrence:
(1) absence of amyloid in tumor
(2) male sex
(3) extrathyroid tumor invasion
2 subgroups with 10 year survival comparable to general population
(1) Patients with hereditary form of medullary carcinoma detected by screening.
(2) Young patients with tumors < 1 cm in diameter and with clinical stage I or II at diagnosis.
