Survival and prognostic factors in thyroid carcinoma.

A multivariate analysis of prognostic factors and survival was carried out in a series of 200 patients with thyroid carcinoma. The cumulative survival rate corrected for intercurrent deaths was higher for papillary carcinoma than for follicular carcinoma both at 5 years (92% vs 74%) and at ten years (87% vs 66%) after the diagnosis. Seventeen of the eighteen patients with anaplastic carcinoma died within 24 months after the diagnosis. The most important independent prognostic factor in patients with papillary or follicular carcinoma, by multivariate analysis, was age at time of diagnosis, followed by tumor penetration beyond the thyroid capsule and follicular histologic type. When different types of treatment were included in the analysis, age at diagnosis still remained the most important prognostic factor. Misdiagnosed intercurrent deaths in the elderly did not explain the negative effect of age on survival.