Surgical treatment of papillary thyroid carcinoma: uni- and multivariate analysis of prognostic factors (TNM staging system included).
Out of 677 patients, who underwent surgery for papillary thyroid carcinoma between '67-'95, we selected for survival uni and multivariate analysis 463 patients with over 5 years of minimal follow up (max 28, mean 11.15 +/- 5.29). Patient's sex, age (over and under 45) tumour size (smaller and larger than 15 mm), stage, any TNM parameter, hystological variety, surgical procedure on the thyroid and nodes were the factors assessed in order to establish the prognosis. Male:female ratio was 1:3, average age 42.2 +/- 0.68; only 25.9% of the patients presented smaller than 15 mm tumors, about 57% positive nodes and 8.85% distant metastases; total or near total thyroidectomy was performed in 86% of the cases and nodal dissection in 68.47%. The 10, 15, 20 year survival rate resulted to be 94.36%, 91.38% and 88.69%; 23 patients (4.96%) died of poorly differentiated and locally advanced carcinoma, but none of them was younger than 45. Age over 45, T4 and M+ stage parameters and dedifferentiated histotype resulted of high value while nodal involvement, interrelated with T and M, showed no independent impact; stage gradually got worse but no difference was found between stage I and II, or T1 and T2. Surgical treatment has not resulted to affect survival, whereas lymphnodes involvement is correlated with complications. Adverse effect of male sex resulted from its interrelation with more advanced stages. A significantly higher relapse rate was found in males and in patients over 45, interrelated with T and N extension: no tumor smaller than 15 mm recurred and no relation was found between recurrence and surgical procedure. Longer follow-up is needed to compare the more conservative treatments with total thyroidectomy and nodal dissection.