Electrical stimulation has been widely applied in medicine to combat microorganisms,1 enhance wound healing,2 and treat tumors,3 as well as promote strengthening and motor control of skeletal muscles.4,5 Common rehabilitation practice is to place electrodes on the skin to stimulate nerves supplying muscle groups of interest to increase strength.6,7 Neuromuscular electrical stimulation (NMES) has been used for decades on a wide array of muscle groups, but it was investigated for dysphagia rehabilitation in neurologically impaired patients in the late 1990s,8,9 and in 2002, the U.S. Food and Drug Administration (FDA) cleared a device for the treatment of dysphagia. Several meta-analyses have since evaluated the effect of NMES on swallowing rehabilitation and revealed a small but significant summary effect size.10,11 More recently, investigation of NMES has focused on its effects as an adjunct to traditional swallowing therapy in patients receiving treatment for locally advanced head and neck cancer.12 However, the FDA applies a general warning to all NMES devices to avoid stimulating over areas of malignancy.13,14 The concern is that applying electrical stimulation to the anterior neck may stimulate tumor growth if there is residual disease or recurrence following treatment. It is common practice to wait at least several months after radiation and/or surgical treatment before initiating NMES to minimize or resolve dysphagia. A drawback to delaying therapy is that by the time NMES has commenced, the patient typically has chronic dysphagia,15 making the condition more difficult to manage. If NMES in the setting of active malignancy proves not to enhance tumorigenic activity, then perhaps its benefit for dysphagia therapy can be enhanced by starting therapy earlier in the rehabilitation period. To our knowledge, there has never been an animal or human study investigating the effects of skin surface electrical stimulation (as in NMES) on an underlying malignancy, located deep to the skin surface but aligned with the location of electrical stimulation. Based on our review of the literature pertaining to electrodes inserted directly into tumors and resulting in tumor destruction,3, 16–21 we hypothesized that NMES will not increase underlying tumor burden.