Prognostic importance of various clinicopathological features in papillary thyroid carcinoma

The influence of various pathological features on tumour recurrences and cancer deaths has been studied in 173 consecutive cases of surgically treated papillary thyroid carcinoma recorded in 1971-1985. During the follow-up (median 7.3 years), 18.6% of the 161 radically treated patients had recurrent disease, and 8.7% died of thyroid cancer. In the univariate life-table analysis, recurrence-free survival was significantly related to age, pTNM category, tumour size, presence of certain growth patterns, tumour necrosis, tumour infiltration in surrounding thyroid tissue and thyroid gland capsule, lymph node metastases, presence of extra-nodal tumour growth and number of positive lymph nodes, whereas only tumour diameter, thyroid gland capsular infiltration and presence of extra-nodal tumour growth remained as significant prognostic factors in the multivariate analysis. Regarding thyroid cancer deaths, sex, age, pTNM category, radicality of surgical treatment, tumour diameter, macroscopic appearance, cellular atypia, tumour necrosis, thyroid gland capsular infiltration, vascular invasion, extra-thyroidal extension and lymph node metastases were all significant variables in the univariate analysis. However, only sex, age, radicality of surgical treatment and vascular invasion were found to be significant predictors of thyroid cancer deaths in the final multivariate Cox model, whereas cellular atypia and necrosis showed a borderline significance. Our study thus documents the independent importance of certain histological features for morbidity and mortality in surgically treated cases of papillary thyroid cancer.