OBJECTIVETo investigate the factors that influence survival of the patients with differentiated thyroid carcinoma in young people and evaluate the efficiency of unilateral lobectomy plus isthmectomy with therapeutic cervical lymph node dissection and postoperative TSH (thyroid stimulating hormone) suppressive therapy.

METHODSOne hundred and thirty-one patients under 30 years old with differentiated thyroid carcinoma treated in this hospital (14 cases no more than and 117 cases more than 16 years) from Jan. 1st, 1985 to Dec. 31st, 1997 were retrospectively reviewed. One hundred and twenty-eight patients were received only surgery and TSH suppressive therapy, and 3 patients received chemotherapy or radiotherapy because of the progressive metastasis in necks or mediastina. A multivariate analysis was performed in these patients by the Cox proportional hazard model.

RESULTSThe mean follow-time (x +/- s) of all patients were (140.86 +/- 43.76) months, with range from 20 to 229 months; Ninety-eight patients followed more than 10 years. Ten patients died of thyroid cancer. The overall 10-year survival rate was 97.18%. The 10-year survival rate for patients < or = 16 years of age and > 16 years were 75.97% and 96.57% respectively (P = 0. 0006). The 10-year survival rate for women and men were 94.91% and 93.69% respectively (P = 0.5261). The 10-year survival rates of patients with papillary thyroid carcinoma and follicular thyroid carcinoma were 93.77% and 96. 55% respectively (P = 0.8137). For patients with tumor size of < or = 1 cm, 1-4 cm and >4 cm the survival rate was 100.0%, 96.40%, and 80.67% respectively (P = 0. 0589). The 10-year survival rates of patients with or without lymph node metastasis were 88.37% and 100. 0% respectively (P = 0.0313). For patients of with or without distant metastasis, The survival rate was 96.64% or 60.00% (P = 0.0000). The 10-year survival rates with or without recurrence were 86. 67% and 95.48% respectively (P = 0. 5681). Using multivariate analysis, risk factors that independently influence survival were distant metastasis, tumor size and age.

CONCLUSIONSThe distant metastasis, tumor size and age at diagnosis were the independent factors influencing survival significantly. The status of lymph node metastasis may have certain effect on the prognosis. Unilateral lobectomy plus isthmectomy with a therapeutic cervical lymph node dissection followed by postoperative TSH suppressive therapy is a favourable model to children and young adults with DTC without distant metastasis, but to the patients with distant metastasis, their prognosis of this therapy model is disappointing.