ASSOCIATION OF P53 PROTEIN EXPRESSION WITH RESPONSES AND SURVIVAL OF PATIENTS WITH LOCALLY ADVANCED ESOPHAGEAL-CARCINOMA TREATED WITH CHEMORADIOTHERAPY

Immunohistochemical analysis was performed to determine the clinical r ole of p53 mutations in patients with locally advanced esophageal carc inomas treated with concurrent chemoradiotherapy. The subjects of this study were 20 patients with previously untreated esophageal carcinoma s with evidence of T4 disease and/or distant node metastases. Treatmen t comprised protracted 5-fluorouracil and 2-h cisplatinum infusions al ong with radiation treatment with a total radiation dose of 60 Gy. Tum or specimens from 18 of the 20 patients were analyzed immunohistochemi cally. Mutant p53 protein expression in the biopsy materials from the primary tumors was analyzed by immunohistochemical staining using a po lyclonal antibody, RSP53. Expression of p53 was detected immunohistoch emically in 10 (56%) of the 18 esophageal tumors, the cancer cell nucl ei of which were diffusely stained. There were no significant differen ces between the patient backgrounds of the p53-''positive'' and ''nega tive'' groups. Four (40%) of the 10 patients with p53 expression achie ved overall complete remissions (CRs) and 7 (70%) of these 10 achieved CRs of their primary tumors. In contrast, none of the 8 p53-negative patients achieved overall CRs and two (25%) achieved CRs of their prim ary tumors. The CR rates overall and of primary tumors tended to be hi gher in the p53-positive than negative group, but the differences were not significant. The survival rate for the 10 patients with p53 expre ssion was better than that for the 8 negative ones (P>0.01): their med ian survival times were 12 and 4.5 months, respectively. Expression of p53 protein may be an indicator of a favorable prognosis in patients with locally advanced esophageal carcinomas treated with concurrent ch emoradiotherapy.