Identification and relationship of HER-2/neu overexpression to short-term mortality in primary malignant brain tumors

Abstract

Introduction: HER-2/neu overexpression has been associated with poor prognosis in solid tumors. The extent to which HER-2/neu is overexpressed in human central nervous system malignancies is unclear. We retrospectively analyzed a large cohort of patients with primary brain tumors to evaluate the prognostic role of HER-2/neu overexpression and clinical characteristics at presentation in patients with shortened survival (< 6 months).

Materials and methods: Between 1986 and 2001, 136 patients (81 males, 55 females) with a mean age of 69 years (age range: 49-78 years), with a biopsy-proven diagnosis of a primary malignant brain tumor and survival of < six months from the time of diagnosis, were identified. Archival tissue samples were analyzed for HER-2/neu overexpression using the Hercep immunohistochemical assay. A score of 2+ or greater on the assay was considered positive for HER-2/neu overexpression. Short-term mortality (less than 6 months) and its predictors were evaluated using multiple logistic regression.

Results: Mean overall survival was 2.8 months. HER-2/neu overexpression was detected in 23 out of 136 specimens (17%). However, HER-2/neu overexpression did not predict increased 6-month mortality (p = 0.43). Interestingly, the presence of HER-2/neu overexpression was associated with a significantly increased risk of an associated second primary malignancy in addition to the primary brain tumor. Other factors examined did not predict increased 6-month mortality either, including site of tumor (p = 0.54), tumor histology (p = 0.77) and presenting symptoms (p = 0.32).

Conclusion: Her-2/neu overexpression was detected in 17% of patients with primary brain tumors, but, did not predict increased short-term mortality in patients with brain tumors surviving less than six months. We were not able to identify any clinical variables that could predict survival in our patient population. At present, there are few reliable prognostic indicators for brain tumors. Further studies are needed to specify whether certain tumor subtypes are more likely to overexpress HER-2/neu and to evaluate the role of HER-2/neu as a target for therapy in malignant brain tumors.