prognostic factors in patients with invasive differentiated thyroid carcinoma who underwent palliative resection in order to determine surgical strategy for locally advanced thyroid carcinoma a multivariate analysis of prognostic factors was carried out with 70 patients of locally advanced thyroid carcinoma who underwent palliative surgery multivariate analysis was conducted by coxs proportional hazard model the patients have been followed up from 5 to 26 years we have demonstrated the influence of age sex distant metastasis pathological findings numbers of adjacent organs infiltrated extent of resection external irradiation and 131i therapy on survival the result of this study showed that age had an impact on survival the survival rate of the patients under 40 years was much better than that of the patients 40 years and over the result implies that aggressive surgery and postoperative adjuvant therapy should be considered in the old patients but not always be indication in the young patients