OVEREXPRESSION OF P53 PROTEIN AND DNA CONTENT ARE IMPORTANT BIOLOGIC PROGNOSTIC FACTORS FOR THYROID-CANCER

Background. Many factors have been reported to be of prognostic import ance for thyroid cancer. Biologic aggressiveness may influence postope rative recurrences and the prognosis of thyroid cancer Immunohistochem ical staining for the p53 protein and DNA content are novel factors th at suggest biologic aggressiveness. Methods. Retrospective study of th e survival rate after operation of differentiated thyroid cancer was u ndertaken at Osaka Police Hospital. Age, gender, operative method, ext ent of lymph node dissection, use of radioiodine, primary or recurrent Armor, tumor tumor size and invasion lymph node involvement, presence of distant metastases, DNA ploidy percentage of S phase and G2M phase fractions, positive staining for the p53 protein, and histologic type and subtype were evaluated as possible Prognostic factors by univaria te and multivariate analyses of survival. Results. Positive staining f or the p53 protein was related to postoperative local recurrence, and DNA ploidy was related to distant metastatic recurrence. Univariate an alysis suggested that age, tumor size and invasion, lymph node involve ment, presence of distant metastases, percentage of S phase fraction, histologic subtype, DNA ploidy, and positive staining ow the p53 prote in were significant prognostic factors. Multivariate analysis suggeste d that positive staining of the protein and DNA ploidy were independen t prognostic factors for overall survival. Conclusions. Both positive staining for the p53 protein and DNA ploidy which suggest biologic agg ressiveness, are independent prognostic factors for overall survival o f patients with thyroid cancer. Examination of these biologic factors may provide new information regarding postoperative recurrences and th e prognosis of thyroid cancer.