Nano-pulse stimulation (NPS) ablate tumors and inhibit lung metastasis on both canine spontaneous osteosarcoma and murine transplanted hepatocellular carcinoma with high metastatic potential

BACKGROUND: Nanosecond pulsed electric field (nsPEF), which is also termed as nano-pulse stimulation (NPS), has the potential of stimulating immune responses toward cancer cells. The current study investigates its local and systemic antitumor efficacy in vivo in late stage tumors with lung metastasis. METHOD: The 12 canines with spontaneous osteosarcomas and 12 nude mice transplanted with human hepatocellular carcinoma were divided randomly and were given NPS treatment, surgery or no treatment control. Nanosecond pulsed electric field was delivered with puncture electrodes at 40 kV/cm with 500 pulses at 1 Hz. The survival time, tumor volume, serum alkaline phosphatase (ALP), joint capsule damage and lung metastasis were followed up. The efficacy was compared with control. RESULTS: Nanosecond pulsed electric field reduced primary tumor volume and extended the survival significantly compared to the control group (P<0.05). Inhibition of serum alkaline phosphatase and lung metastasis without joint deformity or thermal damage were also observed. CONCLUSION: Locally applied nanosecond pulsed electric field is a novel non-thermal ablation method. It can ablate the primary tumor and decrease lung metastasis as a palliative therapy for late stage tumor.