Significance of immunohistochemical expression of p27 and involucrin as the marker of cellular differentiation of squamous cell carcinoma of the esophagus.

PURPOSE

p27kip1 belongs to the KIP/CIP family of cyclin-dependent kinase inhibitors and is considered to be a tumor suppressor. Involucrin has been known as a marker of differentiation of squamous cell carcinoma (SCC). The aim of this study was to evaluate the clinicopathologic significance of the expression of p27 and involucrin in esophageal SCC.

METHODS

Immunohistochemical expression of p27 and involucrin was examined in 70 specimens of esophageal SCC. The correlation of the expression of these proteins and clinicopathologic features was evaluated.

RESULTS

Cellular differentiation in esophageal SCC was significantly correlated with the expression of p27 and involucrin (p = 0.010 and p = 0.002, respectively). Among well, moderately and poorly differentiated SCCs, 45.8 +/- 21.6, 20.0 +/- 15.0 and 10.6 +/- 9.1% of carcinoma cells expressed involucrin, respectively (p < 0.0001 for well vs. poorly, p < 0.0001 for well vs. moderately, and p = 0.042 for moderately vs. poorly). There existed a more powerful statistical difference regarding the histological grade between SCCs with the expression of both p27 and involucrin and tumors with other expression patterns (p = 0.0001).

CONCLUSIONS

Expression of both p27 and involucrin can be a powerful biological marker of cellular differentiation of esophageal SCC.