Thyroid cancer treated in Chang Gung Memorial Hospital (northern Taiwan) during the period 1979-1992: clinical presentation, pathological finding, analysis of prognostic variables, and results of treatment.

This study is a retrospective analysis of 248 thyroid cancer patients who received their primary treatment in the Chang Gung Memorial Hospital during the period January 1979 to December 1992. Among these cases, there were 173 papillary thyroid cancers (69.8%), 52 cases of follicular thyroid cancer (21%), 7 cases of medullary thyroid cancer (2.8%), and 16 cases of anaplastic thyroid cancer (6.5%). The subjects included 184 female patients with a mean age of 40.7 +/- 14.3 years and 64 males patients with a mean age of 49.2 +/- 14.3 years. Most of the cases had a nearly total thyroidectomy after the diagnosis was confirmed by frozen section during the operation. During the follow-up period, 19 (8.2%) patients diagnosed with well-differentiated thyroid cancer died of thyroid cancer in contrast to 12 patients (75%) with anaplastic thyroid cancer. The 1-year Greenwood survival probabilities after the disease is diagnosed in papillary, follicular, and anaplastic thyroid cancer are 0.98, 0.86, and 0.25, respectively. For the analysis of prognostic variables in well-differentiated thyroid cancer patients, 16 factors were entered for univariate and multivariate analysis. Using a log-rank univariate analysis, survival was significantly associated with the cell type of the primary tumor, age, clinical staging, postoperative 131I pattern, tumor size, postoperative thyroglobulin (Tg) level and postoperative x-ray results. In the Cox multivariate regression analysis the combination factors that gave the best prognostic value were the association of x-ray finding (P = .004), age (P = .017), and Tg level (P = 0.19). In conclusion, thyroid cancer is not an unusual disease in Taiwan. As previously reported anaplastic thyroid cancer has a poor prognosis. In this limited period of follow-up study, the patients' age with postoperative first positive x-ray finding and Tg level may provide the prognostic factors for patients with well-differentiated thyroid cancer.