Development and Preliminary Validation of a Wearable Tumor Treating Fields Device for Breast Cancer Therapy.

[INTRODUCTION] Tumor treating fields (TTFields) is a novel non-invasive tumor treatment method that can inhibit the growth of a variety of tumors with few side effects. However, the devices used for TTFields therapy are relatively scarce and has great limitations in scientific research and clinical application scenarios.

[OBJECTIVE] The objective of this study is to address the challenge posed by the large size of TTFields therapeutic devices, which adversely affect patient mobility, quality of life, and treatment adherence. Furthermore, this study aims to explore the potential of TTFields as a therapeutic approach for breast cancer treatment, evaluating its efficacy and feasibility in extracranial applications.

[METHODS] In this study, we designed a wearable device called TTF-Backpack integrates a stimulator for generating alternating electric field (0~250 kHz, 0~40 mA). In addition, we planned circuit experiments to evaluate the electrical performance of the device and validated its efficacy by establishing rat models of breast cancer syngeneic graft. The models were treated with alternating electric fields (frequency 250 kHz, intensity 1-1.5 V/cm) for 24 hours daily over 7 days.

[RESULTS] The maximum output voltage of TTF-Backpack is approximately 55V with the frequency bandwidth of 0~250 kHz, and its current can reach 40 mA. Furthermore, animal experiment results indicated that TTF-Backpack can inhibit the progression of breast cancer. Analysis of tumor tissue sections demonstrated that the mRNA levels of ki67, the mRNA and protein expression levels of the pro-apoptotic gene Bax upregulated, while the protein expression level of the anti-apoptotic marker Bcl2 downregulated significantly.

[CONCLUSION] This study demonstrates the feasibility and preliminary efficacy of a novel wearable TTFields device for breast cancer therapy.