Prognostic factors and therapeutic strategy for anaplastic carcinoma of the thyroid

Although anaplastic thyroid carcinoma (ATC) is one of the most aggressive m alignancies, a few patients survive for a fairly long time after modern int ensive treatment. We tried to identify prognostic factors of ATC to assist in deciding on the proper therapeutic strategy in individual patients, Of 4 7 patients with;ITC (1976-1999), 3 patients with "incidental" ATC (largely differentiated thyroid carcinoma with a small region of ATC) were excluded because they had a favorable outcome. The 1-year survival rate of the remai ning 44 patients with clinically distinct ATC was 16%. The presence of acut e symptoms, large tumor (> 5 cm), distant metastasis, and leukocytosis (whi te blood cell count greater than or equal to 10,000/mm(3)) proved to be sig nificant risk factors. Multivariate analysis by the Cox proportional hazard model showed that these four factors were independent factors for predicti ng death from ATC, We devised a novel prognostic index (PI) based on the nu mber of these four unfavorable characteristics the patient possessed. Patie nts with a PI of less than or equal to1 had a 62% survival rate at 6 months , whereas no patients with a PI of greater than or equal to3 survived longe r than 6 months. All patients with a PI of 4 died from their disease within 3 months. Nine patients received multimodal treatment with a combination o f surgery, external irradiation, and chemotherapy and had a long survival ( mean 333 +/- 68 days; one patient is still alive and tumor-free), with a me an PI of 0.6, Our PI is useful as a means of selecting patients for aggress ive therapy. When the PI is low, multimodal treatment should be attempted t o obtain the best survival results; if it is high most patients are too ser iously ill to tolerate intensive treatment and palliative therapy is recomm ended.