Correlation between amplification of the gene for the epidermal growth factor receptor (EGFR), data from preoperative proton-MR-spectroscopy (1HMRS) and histomorphometric data of glioblastomas.

OBJECTIVE

To investigate a correlation between preoperative data from proton-MR-spectroscopy (1HMRS), genomic alterations (epidermal growth growth factor receptor [EGFR] gene amplification) and histomorphometric data from glioblastomas.

STUDY DESIGN

In surgical specimens from 18 patients with glioblastomas, the degree of amplification of the gene for EGFR was determined in the region with the largest Ki-67 proliferation index by differential polymerase chain reaction.

RESULTS

Correlation analysis showed significant positive correlation between degree of EGFR gene amplification and choline and total creatine (CHO/TCR) ratio, indicating increased membrane turnover. Cases with a high EGFR/interferon ratio showed a tendency toward a low lipid peak, whereas cases with a low EGFR/interferon ratio showed a large variation of the lipid peak. Differences were observed regarding quantitative histomorphologic data of tumor cell nuclei, especially nuclear size and shape. Together with the EGFR/interferon ratio, these morphometric data provided a good reclassification of cases with low and with high values for both spectroscopic variables by means of cross-validated linear discriminant analysis.

CONCLUSION

The results provide further evidence for the biologic significance of metabolic data from preoperative 1HMRS, because these metabolic data showed a significant statistical relationship with histomorphology and a frequently occurring molecular biologic alteration (EGFR gene amplification) in glioblastomas.