Background: We have been investigating various molecules correlated with the malignancy of esophageal squamous cell carcinoma and, in the present study, we examined the correlation of four of them (KAI1, FAK, EphA2, Ki-67 labeling index) with the prognosis of affected patients. Furthermore, the use of biopsy samples was studied to evaluate whether the grade of tumor malignancy can be determined before treatment in a clinical setting.
Materials and methods: Tissue specimens that had been surgically removed from 91 patients with thoracic esophageal cancer and 247 biopsy samples were examined. The malignancy index (MI) was defined in terms of the KAI1, FAK and EphA2 scores and the Ki-67 labeling index, and the reliability and utility of the correlation between MI and prognosis was evaluated.
Results: The mean 5-year survival rate of patients with MI=0 was 100%, while that of patients with MI=1, 2 and 3 was 70%, 48% and 10%, respectively. Patients with MI=4 all died, with the exception of one who has been observed for 3 years. The rate of concordance between the biopsy samples and surgical specimens was 79.4% for KAI1, 88.2% for FAK and 73.5% for EphA2, and the rates of concordance for 1, 2, 3, 4, 5, 6, 7 and 8 biopsy samples were 66.7%, 64.1%, 74.5%, 90.7%, 91.7%, 83.3%, 100% and 100%, respectively.
Conclusion: It may be feasible to evaluate the malignancy of tumor cells and to predict patient outcome by using multiple marker molecules. It is anticipated that such data will accelerate the development of "tailor-made" therapy.