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 theclinical role of p53 mutations in patients with locally advancedesophageal carcinomas treated with concurrent chemoradiotherapy.The subjects of this study were 20 patients with previouslyuntreated esophageal carcinomas with evidence of T4 diseaseand/or distant node metastases. Treatment comprised protracted5-fluorouracil and 2-h cisplatinum infusions along with radiationtreatment with a total radiation dose of 60 Gy. Tumor specimensfrom 18 of the 20 patients were analyzed immunohistochemically.Mutant p53 protein expression in the biopsy materials from theprimary tumors was analyzed by immunohistochemical stainingusing a polyclonal antibody, RSP53. Expression of p53 was detectedimmunohistochemically in 10 (56%) of the 18 esophageal tumors,the cancer cell nuclei of which were diffusely stained. Therewere no significant differences between the patient backgroundsof the p53-"positive" and "negative" groups. Four (40%) of the10 patients with p53 expression achieved overall complete remissions(CRs) and 7 (70%) of these 10 achieved CRs of their primarytumors. In contrast, none of the 8 p53-negative patients achievedoverall CRs and two (25%) achieved CRs of their primary tumors.The CR rates overall and of primary tumors tended to be higherin the p53-positive than negative group, but the differenceswere not significant. The survival rate for the 10 patientswith p53 expression was better than that for the 8 negativeones (P > 0.01): their median survival times were 12 and4.5 months, respectively. Expression of p53 protein may be anindicator of a favorable prognosis in patients with locallyadvanced esophageal carcinomas treated with concurrent chemoradiotherapy.