Expression of dysadherin and cytokeratin as prognostic indicators of disease-free survival in patients with stage I NSCLC.

Adjuvant chemotherapy is required following the resection of aggressive NSCLC. It is therefore necessary to identify factors that accurately predict prognosis. Tumor specimens were collected from 107 patients who underwent a complete resection for NSCLC from 1994-2000 in this Department. The expression of E-cadherin, dysadherin, and cytokeratin in stage I NSCLC specimens was analyzed by immunohistochemistry. Seventeen percent of tumors showed reduced E-cadherin immunostaining. Twenty-nine per cent of tumors showed dysadherin expression in over 50% of the cancer cells. Positive expression of cytokeratin was identified in 30 (28.0%) patients. The incidence of positive expression of dysadherin in females and elderly patients was higher than that in other patients. Cytokeratin immunoreactive tumor cells in lymph nodes were identified in 34 (28.0%) out of 107 patients. The incidence of positive expression of cytokeratin in T1 tumors was higher than that in T2 tumors. There was a significant inverse correlation between the expression of E-cadherin and dysadherin. The increased expression of cytokeratin was significantly associated with recurrence. Logistic regression models indicated that cytokeratin expression was an independent predictor of recurrence. The increased expression of dysadherin and cytokeratin had a significant impact on patient survival. Furthermore, tumors with an increased expression of dysadherin and a reduced expression of E-cadherin showed the worst prognosis. The detection of dysadherin in tumors and cytokeratin in the lymph nodes may be a potential significant indicator of a poor prognosis for patients who undergo complete resection of stage I NSCLC.