Although the development of various chemotherapeutic drugs has greatly improved clinical outcomes and survival rate of cancer patients, it also causes various adverse side effects. Chemotherapy-induced cognitive impairment, often referred to as chemobrain, has drawn increasing attention due to the rise in the number of cancer survivors over the past decade. Numerous studies have shown that chemotherapy can cause acute and long-term post-treatment cognitive impairment, including problems with visual and verbal memory, forgetfulness, difficulty in learning, attention, concentration and coordination of multitasking and organization. Over 75% cancer patients reported to experience acute cognitive symptoms during chemotherapy and 17%-34% of them have long-term post-treatment cognitive deficits which can persist up to 10 years. Breast cancer survivors may display higher prevalence of post-treatment cognitive impairment. The severity of reported chemobrain symptoms is variable, from subtle to more severe. Chemobrain has become an apparent quality-of-life issue for survivors and will be encountered more frequency in the future. However, there are no effective interventions available to prevent and treat chemobrain, although some pharmacological, antioxidant and various cognitive approaches have been tested.

It is believed that chemobrain is a consequence of brain neuronal injury induced by systemically administered chemotherapeutic agents via direct and indirect mechanisms, resulting in the suppression of neuronal cell proliferation, epigenetic modification and microstructural changes of the brain. These pathological circumstances are largely developed from alternations in cytokine milieu. While physical and psychological stressors that cancer patients experienced after diagnosis, chemotherapy and long-term follow-up have been shown to increase circulating cytokine levels and increased cytokine levels are associated with cognitive decline in cancer patients, the administration of chemotherapy also results in cytokine production at peripheral and central levels as the medications induce tumor cell death and collateral tissue injury. Patients undergoing chemotherapy have been found to display significant increases in multiple cytokines.

A large body of evidence well confirms that acupuncture is effective in reducing anti-cancer treatment-caused side effects, including pain, nausea, hot flashes, fatigue, xerostomia, anxiety, depression and sleep disturbance. Numerous studies further have shown the effectiveness of acupuncture therapy in improving cognitive function of patients with mild cognitive impairment (MCI) and various dementia. The reduced severity of cognitive symptoms is associated with neuroimaging improvement in brain regions associated with learning and memory process. Acupuncture also ameliorates cognitive impairment in various animal models. Studies have further revealed that the cognition-improving effects of acupuncture are associated with the inhibition of cytokine-mediated neuronal cell apoptosis, inflammatory reaction and oxidative cellular injury and the effects in reducing cognitive symptoms are related to the protection of neuronal cells, improvement of electrophysiological activities of the hippocampus and brain cell proliferation. Moreover, acupuncture also displays a significant effect in facilitating the recovery of the brain at microstructural histopathological level in patients with cerebral infarction and in rats with transient focal cerebral ischemia. The investigators therefore hypothesize that acupuncture may be also effective in preventing and reducing chemotherapy caused cognitive impairment.

Recently, the investigators have developed a novel acupuncture stimulation called dense cranial electroacupuncture stimulation (DCEAS) on the basis of neuroanatomical rationale. In this mode, electrical stimulation is delivered on dense acupoints located on the forehead innervated by the trigeminal nerve. The trigeminal sensory pathway has much intimate fiber connections with brain regions associated with sensory, locomotor, visceral function, sleep, emotion, learning and memory. Therefore, DCEAS can effectively modulate brain functions. Over the past 5 years, the investigators have completed several clinical studies and demonstrated the benefits of DCEAS in the treatment of major depression, insomnia, OCD, postpartum depression and post-stroke depression. In the proposed study, a combination of DCEAS and body acupuncture will be employed to prevent and treat chemobrain in breast cancer patients.