MAGE-E1 Expression in Non-Small Cell Lung Cancer
Department of Thoracic Surgery, Kyoto University Hospital, Kyoto, Japan
Aim: MAGE (melanoma-associated antigen) was the first Cancer/Testis antigen to be defined, and over 25 different MAGE genes have been identified until now. MAGE-E1 is a novel member of MAGE family, but the clinical significance in non-small cell lung cancer (NSCLC) remains unknown. We sought to determine whether or not MAGE-E1 gene expression correlated with clinicopathological factors and MAGE-E1 might be a biomarker in patients with NSCLC. Methods: A total of 202 patients with pathologic (p-) stage I-IIIA, NSCLC were reviewed. MAGE-E1 expression was examined by immunohistochemistry. Results: MAGE-E1 expression in tumor cells was strong in 121 patients (69%), and weak in the other 81 patients. Strong MAGE-E1 expression was more frequently seen in squamous cell carcinoma patients (56/75, 75%) than in adenocarcinoma patients (55/109, 51%; p<0.01). MAGE-E1 status was not significantly correlated with other patients’ characteristics including sex, age, performance status, grade of tumor differentiation, pT-factor, or pN-factor. The mean proliferative index (PI) for strong MAGE-E1 tumor was 51, which was significantly higher than that for weak MAGE-E1 tumor (PI, 42; p=0.04), and aberrant expression of p53 was also more frequent in strong MAGE-E1 tumor (64/121, 53%) than in weak MAGE-E1 tumor (21/81, 25%; p<0.01). There was no significant difference according to the MAGE-E1 status in apoptotic index or microvessel density. There was no difference in the postoperative survival between weak MAGE-E1 patients and strong MAGE-E1 patients (5-year survival rates, 65% and 69%, respectively; p=0.742) Conclusions: Enhanced MAGE-E1 expression was more frequent in squamous cell carcinoma, and was also significantly correlated with active tumor-cell proliferation and aberrant p53 status. However, MAGE-E1 status was not correlated with the postoperative survival.
Paper presented at the International Symposium on Predictive Oncology and Intervention Strategies; Nice, France; February 7 - 10, 2004; in poster session 797 (Manifestations of cancer).