title: Tumor growth delay by adjuvant alternating electric fields which appears non-thermally mediated.
abstract: Delivery of the so-called Tumor Treatment Fields (TTFields) has been proposed as a cancer therapy. These are low magnitude alternating electric fields at frequencies from 100 to 300 kHz which are applied continuously in a non-invasive manner. Electric field delivery may produce an increase in temperature which cannot be neglected. We hypothesized that the reported results obtained by applying TTFields in vivo could be due to heat rather than to electrical forces as previously suggested. Here, an in vivo study is presented in which pancreatic tumors subcutaneously implanted in nude mice were treated for a week either with mild hyperthermia (41 °C) or with TTFields (6 V/cm, 150 kHz) and tumor growth was assessed. Although the TTFields applied singly did not produce any significant effect, the combination with chemotherapy did show a delay in tumor growth in comparison to animals treated only with chemotherapy (median relative reduction=47%). We conclude that concomitant chemotherapy and TTFields delivery show a beneficial impact on pancreatic tumor growth. Contrary to our hypothesis, this impact is non-related with the induced temperature increase.
authors.affiliation: Universitat Pompeu Fabra, Barcelona, Spain. Electronic address: quim.castellvi@upf.edu.
authors.forename: Quim
authors.initials: Q
authors.lastname: Castellví
authors.affiliation: Institut Català d'Oncologia-IDIBELL, Hospital Duran i Reynals, l'Hospitalet de Llobregat, Spain.
authors.forename: Mireia M
authors.initials: MM
authors.lastname: Ginestà
authors.affiliation: Institut Català d'Oncologia-IDIBELL, Hospital Duran i Reynals, l'Hospitalet de Llobregat, Spain.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Capellà
authors.affiliation: Universitat Pompeu Fabra, Barcelona, Spain.
authors.forename: Antoni
authors.initials: A
authors.lastname: Ivorra
mesh_terms: D000818:Animals; D002455:Cell Division; D004560:Electricity; D051379:Mice; D008819:Mice, Nude; D009369:Neoplasms / Q000473:pathology*
keywords: Alternating electric field; Chemotherapeutic adjuvant; Hyperthermia; Pancreatic tumor; TTFields