p53 labeling index in cholangioscopic biopsies is useful for determining spread of bile duct carcinomas

Background: Preoperative biopsy specimens obtained by means of percutaneous transhepatic cholangioscopy are useful for planning curative resection of bile duct carcinoma in an effort to improve survival. However, tissue diagnosis is sometimes difficult. This study evaluated the usefulness of p53 immunostaining of cholangioscopic specimens for determination of tumor spread. Methods: A total of 107 biopsy specimens from 28 patients with bile duct carcinoma was selected. Before surgery, these specimens were diagnosed histopathologically (hematoxylin and eosin staining) as positive or negative for carcinoma. After definitive surgery, specimens were immunostained with anti-p53 antibody. Results: Eighteen of 28 cases (64%) were positive for p53. Among these, 86% obtained from the main carcinomatous lesion or an area of superficial spread of the carcinoma exhibited a p53 labeling index (LI) over 25% as opposed to a p53 LI under 25% for all specimens obtained from noncarcinomatous lesions. Twelve specimens from 8 cases were classified before surgery as indeterminate (hematoxylin and eosin staining). The criterion of p53 LI over 25% was applicable in 11 of the 12 specimens. Conclusion: The p53 immunostaining of biopsy specimens obtained by means of percutaneous transhepatic cholangioscopy is helpful in determining tumor spread in bile duct carcinoma. (Gastrointest Endosc 2002;56:688-95.)