DIFFERENTIATED THYROID-CANCER IN CHILDREN AND ADOLESCENTS - CLINICAL OUTCOME AND MORTALITY AFTER LONG-TERM FOLLOW-UP

Background. Children and adolescents with differentiated thyroid cance r (DTC) have a good prognosis and prolonged survival even when extensi ve regional disease or lung metastases are present at the diagnosis; v ery-long-term follow-up is needed to appreciate what, if any, impact t he disease may exert on the ultimate outcome. Methods. We retrospectiv ely reviewed the clinical course of 112 patients with DTC who register ed at M. D. Anderson Cancer Center between 1944 and 1986, were younger than 20 years old at the time of diagnosis, and were followed for at least 10 years. Surgery alone or combined with radioactive iodine or r adiotherapy was used for most cases. Results. At the time of most rece nt contact, 99 patients remained alive and 13 had died. The 99 patient s had 25 +/- 0.9 years of available follow-up (mean,SEM) and were 41 /- 0.9 years of age at time of last contact; one fourth had had recurr ent disease at some point since diagnosis. Among the 13 patients who d ied, one died of complications from coexisting diabetes mellitus, and the cause of death was not clear in one other case. Two patients died of breast cancer 13 and 15 years after thyroid cancer diagnosis. In th ree cases, cause of death could be considered etiologically related to initial radiotherapy: one patient developed tracheal necrosis 26 year s after diagnosis and died of upper airway complications, whereas anot her two patients developed sarcomas of the cervical region 22 and 29 y ears after thyroid cancer diagnosis. Lastly, six patients died of thyr oid cancer 26 +/- 3.1 years after initial diagnosis (at age 40 +/- 2.1 years). Among these cases. one patient had invasive disease and lung metastases at diagnosis and died of progressive lung metastases after 36 years. The other five patients were initially seen with local/regio nal disease and developed lung and skeletal metastases after a 2- to 2 0-year disease-free inter val. Conclusions. Our findings support the c linical impression that children and adolescents with DTC live for man y years regardless of apparent extent of disease at diagnosis or devel opment of recurrence. Indeed, overall survival was 100% at 10 years ev en in patients with distant metastases. However, attention to these pa tients' clinical course beyond the first decade indicates that a small minority (5% to 7%) of patients eventually succumb to progressive dis ease and that a similar number develop possibly treatment-related leth al complications or second neoplasms. We suggest lifelong surveillance for all such patients. (C) 1998 John Wiley & Sons, Inc.