REOPERATION FOR RECURRENT OR PERSISTENT MEDULLARY-THYROID CANCER

Background. Initial operations for medullary thyroid cancer (MTC) freq uently do not eradicate all disease, as evidenced by persistently elev ated levels of stimulated plasma calcitonin. Methods. Thirty-two patie nts with MTC and elevated stimulated plasma calcitonin levels after th yroidectomy were studied between 1990 and 1993. Thirty-five repeat nec k explorations and microdissections were performed. Four patients also underwent a median sternotomy and mediastinal dissection. Results. In nine patients (group 1), stimulated plasma calcitonin levels were und etectable after reoperation, whereas in 13 cases (group 2) the calcito nin levels decreased by 40% or more. In 10 cases (group 3) the CT leve ls did not decrease. Primary tumors that exhibited invasive features ( invasion of adjacent structures or extranodal or extracapsular spread) were found more often in Patients from group 3 than in patients from groups 1 or 2 (p < 0.05, Fisher's exact test). Conclusions. Reoperatio n resulted in normalization of calcitonin levels in 28% of patients an d a decrease in calcitonin levels by 40% or more in another 42% of pat ients. The data also suggest that patients whose primary MTC has invad ed tissues beyond the thyroid gland or a lymph node capsule are less l ikely to benefit from repeat operation.