OBJECTIVES: Tumor Treating Fields (TTFields) are a non-invasive cancer treatment 
modality approved for the treatment of patients with recurrent glioblastoma. The 
present study determined the efficacy and mechanism of action of TTFields in 
preclinical models of pancreatic cancer.
METHODS: The effect of TTFields in vitro was assessed using cell counts, 
clonogenic assays, cell cycle analysis and analysis of mitotic figures. The 
effect in vivo effect was studied in the PC1-0 hamster pancreatic cancer model.
RESULTS: Application of TTFields in vitro showed a significant decrease in cell 
count, an increase in cell volume and reduced clonogenicity. Further analysis 
demonstrated significant increase in the number of abnormal mitotic figures, as 
well as a decrease in G2-M cell population. In hamsters with orthotopic 
pancreatic tumors, TTFields significantly reduced tumor volume accompanied by an 
increase in the frequency of abnormal mitotic events. TTFields efficacy was 
enhanced both in vitro and in vivo when combined with chemotherapy.
CONCLUSIONS: These results provide the first evidence that TTFields serve as an 
effective antimitotic treatment in preclinical pancreatic cancer models and have 
a long term negative effect on cancer cell survival. These results make TTFields 
an attractive candidate for testing in the treatment of patients with pancreatic 
cancer.