Prognostic value of proliferating cell nuclear antigen immunostaining using a thermal retrieval technique in esophageal carcinoma

Abstract

The significance of proliferating cell nuclear antigen immunostaining in esophageal carcinoma was investigated using an antigen retrieval technique. Preliminary examination revealed that heating in a bath at 80°C in phosphate buffer solution resulted in successful proliferating cell nuclear antigen immunostaining of paraffin sections fixed in formalin for less than seven days. Formalin-fixed, paraffin-embedded sections from 79 surgical cases were examined in this study using the antigen retrieval technique. The proliferating cell nuclear antigen labeling index varied from 84.0% to 27.8%, (mean 60.0 ± 14.4%). There were no significant differences in the index as a function of the histologic type, depth of invasion, node status or stage. The five-year survival rate of the high (>60) and low (<60) proliferating cell nuclear antigen labeling index groups were 34% and 64%, respectively (P < 0.01). In conclusion, proliferating cell nuclear antigen immunostaining using a thermal antigen retrieval technique is a useful indicator of the prognosis of esophageal carcinoma.