Abstract
We performed an immunohistochemical analysis on mutant epidermal growth factor receptor (ΔEGFR) expression using an anti-ΔEGFR monoclonal antibody, DH8.3, on seventy-four astrocytic tumors obtained during surgeries at Saitama Medical School. At the same time, expressions of wild-type EGFR, TP53 and CDKN2A were analyzed to recognize their mutual relationships and possible contributions to patients'survival time. Results : 1) ΔEGFR expression was observed in 0/19 (0%) diffuse astrocytoma cases, 3/14 (21.4%) anaplastic astrocytoma cases, and 20/41 (48.8%) glioblastoma cases. 2) EGFR expression was more frequent in TP53-negative cases, and in CDKN2A-negative cases as well, although it did not reach the statistically significant level of p=0.05 by chi-square test. 3) Univariate and multivariate analyses of survival time did not show ΔEGFR being a significant and independent prognostic factor. Conclusion: Although ΔEGFR promotes glioblastoma progression in vivo through several activities such as down-regulating p27(a negative regulator of the cell cycle) and BclX(L) (an inhibitor of apoptosis), and promoting tumor cell invasion, its clinical significance still remains to be elucidated.
