Objective: Several Cytokeratin (CK) isoforms have been analyzed in cervical intraepithelial lesions. However, previously reported numbers of specimens have been too low to evaluate any correlation between CK and CIN.
Methods: We examined the immunohistochemical staining of p16, CK8, and CK17 in 134 cervical tissues obtained by punch biopsy and graded as follows: CIN I (n=39), CIN II (n=31), CIN III (n=43), SCC (n=21).
Results: p16 staining was identified in 74.4% of CIN I, 93.6% of CIN II, 97.7% of CIN III, and 100% of SCC cases. CK8 and CK17 staining were identified in 12.8% and 33.3% of CIN I, 22.6% and 58.1% of CIN II, 62.8% and 81.4% of CIN III, and 71.4% and 95.2% of SCC cases, respectively. Interestingly, positivity for CK8 and CK17 correlated with increasing lesion grade of the intraepithelial lesions and also correlated with p16 staining (p16, p=0.0008; CK8, p<0.0001, and CK17, p<0.0001), and a coordinate expression profile of CK8[+]/CK17[+] correlates with increasing CIN grade and carcinoma (likewise, a coordinate expression profile of CK8[-]/CK17[-] correlates with decreasing CIN grade and absence of carcinoma), but expression of just CK8 (CK8[+]/CK17[-]) or just CK17 (CK8[-]/CK17[+]) does not correlate with increasing CIN grade and carcinoma.
Conclusions: Results of the present study showed that p16, CK8, and CK17 immunostaining differed according to the degree of cervical intraepithelial lesions and SCC, and surprisingly, that staining was significantly correlated with increasing lesion grade of CIN and SCC.