Immunohistochemical Expression of Cathepsin D in Primary and Recurrent Squamous Cell Carcinoma

The aim of this study is to analyze and compare the immunohistochemical expression of cathepsin B in primary oral squamous cell carcinoma (OSCC) and recurrent OSCC.

A total of 50 cases were studied immunohistochemically for rabbit polyclonal antihuman cathepsin D expression. A total of 10 cases of breast carcinoma were taken as positive controls. Immunohistochemical staining was performed using labeled streptavidin-biotin technique.

All the 45 cases of OSCC, both primary and recurrent cases included, showed varying grades of cathepsin D immu-noreactivity. Statistical significance at 5% level was observed in cathepsin D expression between the different grades of well, moderate, and poorly differentiated primary squamous cell carcinomas. In the comparison of cathepsin D staining intensity among primary squamous cell carcinomas with and without recurrence, a statistical significance between the groups was observed when the p-value was at 10%, but the same comparison was not significant when the p-value was at 5%.

Cathepsin D expression in primary squamous cell carcinomas with recurrences was very variable as compared with primary squamous cell carcinomas without recurrences. Comparison of cathepsin D expression in primary with their recurrent counterparts showed mostly similar intensity of expression in recurrent carcinomas, thus suggesting its limited usefulness in predicting recurrence.

Although cathepsin D might have shown limited usefulness in predicting cancer recurrence, it, however, is a proven valuable tool to detect the aggressiveness of various other tumors, and if corroborated with a larger sample may hold the key to early, more effective, and more specific treatment modalities for cases of oral cancer also.