CANCERS DIFFERENCIES DE LA THYROIDE DE L'ENFANT. EXPERIENCE DE L'INSTITUT GUSTAVE-ROUSSY

Purpose: despite favorable long term survival of children with differentiated thyroid carcinoma (DTC), cancer related deaths have been reported. This study was undertaken to determine prognostic factors, treatment and follow-up modalities, and long term outcome of this rare disease. Patients: ninety-eight children with DTC who were 16 years old or younger at the time of initial treatment were followed for a median time of 13.8 yrs. Results: initially, 19% had lung metastases and 66% had palpable lymph nodes. Capsular invasion was found in 59% and histological lymph node involvement in 88%. Sixty patients were in complete remission after initial treatment, of whom 20 relapsed. Twenty-one patients without distant metastases at presentation underwent incomplete surgery, of whom 12 relapsed. Lung metastases were observed in 36 patients, more frequently in children 7 years old or younger at initial treatment and in those with extended thyroid tumour. Among them, 30 were treated with radioiodine and 25 achieved a complete remission. Consequences of radioiodine treatment were not significant. Six patients died from metastases at ages ranging from 19-44 yrs, 12-33 yrs after initial treatment. All these 6 patients were less than 10 years old at the time of initial treatment. Despite favorable long term survival (93.6% at 20 yrs), the standardized mortality ratio was equal to 6.4. Conclusion: younger age is associated with more aggressive disease. Complete surgical treatment and strict follow-up are warranted.