P33. Potential clinical relevance of in vitro migratory activity in malignant pleural mesothelioma

Abstract

Background

Malignant pleural mesothelioma (MPM) displays locally invasive behavior and local recurrence. Recently we demonstrated that MPM cells have a high migratory potential in vitro. Accordingly, in the present study the correlation of in vitro migration with histological subtype and clinical outcome has been investigated.

Methods

Five international cell lines and seventeen cell lines established in our laboratory were analyzed by long-term videomicroscopy. Average migrated distance was calculated for all cell lines and dichotomized to slow and fast migratory cells at the cut-off of 90 micron per day. Correlation of migratory potential and histological subtype was performed by Fisher’s exact test and by Mann-Whitney analysis. Kaplan-Meier analysis was performed for overall survival in the slow and fast migratory group.

Results

A total of 13 epitheloid, seven biphasic and two sarcomatoid lines were analyzed. There was no significant difference in the ratio of slow migratory potential in epitheloid and non-epitheloid cell lines (54% and 44%, respectively). However, biphasic cell lines showed a modestly increased albeit not significantly elevated migratory potential compared to epitheloid MPM cells. Interestingly, patients with high motility MPM cells had a non-significant decrease in median overall survival when compared to those with tumor cells characterized by slow migratory activity (255 vs. 338 days, respectively).

Conclusions

Based on the study panel of our MPM cell lines, there is a tendency for higher migratory activity in biphasic cell lines and for decreased overall survival for patients with highly migratory tumor cells. Accordingly, the high migratory potential of MPM cells may indeed be an important component of the malignant phenotype of MPM. Cell migration might be—beside its potential prognostic value—a promising new target for therapeutic intervention.