Acupuncture improves perceived cognitive impairment in breast cancer survivors

Acupuncture improves perceived cognitive impairment in breast cancer survivors

Real acupuncture and sham acupuncture were more effective at improving perceived cognitive impairment in breast cancer survivors compared to usual care, while real acupuncture was superior to sham acupuncture in improving objective cognitive function. This is according to the results of the randomized Phase II ENHANCE clinical trial presented at the San Antonio Breast Cancer Symposium (SABCS), December 9-12, 2025.

More than 40% of breast cancer survivors experience cancer-related cognitive difficulties, sometimes referred to as "brain fog" or "chemo brain," according to Jun J. Mao, MD, MSCE, Laurance S. Rockefeller Chair in Integrative Medicine and director of Integrative Medicine and Wellness Services at Memorial Sloan Kettering Cancer Center. “Cancer-related cognitive difficulties can make it difficult to complete everyday tasks and affect overall quality of life,” Mao explained. “Unfortunately, there are very few treatments supported by evidence for this problem.”

Previously, Mao and his colleagues found that insomnia was associated with cognitive difficulties in over 1,000 breast cancer survivors and that in a previous study, acupuncture improved insomnia and may have improved cognitive function compared to cognitive behavioral therapy for insomnia (CBT-I). To further test the effectiveness of acupuncture in improving cognitive function in breast cancer patients, researchers designed a three-arm study comparing real acupuncture with sham acupuncture and usual care given at the doctor's discretion. Sham acupuncture is intended to mimic the experience of real acupuncture and provide a similar overall relaxing experience. However, there are some key differences: Sham acupuncture uses locations on the body that are not considered traditional acupuncture points, and the needles do not penetrate the skin.

Acupuncture should be viewed as a complex procedure that includes both needling and the care provided. Simply believing that you are receiving helpful treatment and relaxing by lying down for 20 to 30 minutes can have potential therapeutic benefits, even if the needles are not inserted or placed at specific therapeutic points. By comparing real acupuncture with sham acupuncture, rather than just usual care, we were able to better understand whether the benefits were due to the acupuncture technique itself or the overall experience.”

Jun J. Mao, MD, MSCE, Laurance S. Rockefeller Chair in Integrative Medicine and Director of the Integrative Medicine and Wellness Service at Memorial Sloan Kettering Cancer Center

The clinical trial included 260 women with a history of stage 0-3 breast cancer who had completed treatment, had no signs of cancer, and self-reported moderate or greater cancer-related cognitive difficulties and insomnia. Participants were randomly assigned to treatment with real acupuncture (129), sham acupuncture (70), or usual care (61). Real or sham acupuncture treatments were administered once weekly for 10 weeks, and cognitive function was assessed at baseline, 10 weeks, and 26 weeks.

Perceived cognitive function was measured using the Functional Assessment of Cancer Therapy - Cognitive Function (FACT-Cog PCI), a validated patient-reported outcome that asks patients to complete a survey about how they feel their memory, attention, and ability to perform everyday tasks have been affected. Objective cognitive function was measured using the Hopkins Verbal Learning Test-Revised (HVLT), which measures memory, learning, or attention performance using standardized tasks.

“These two measures capture different aspects of cognition and often do not agree,” Mao said. "In our study, of participants who reported moderate to severe cognitive difficulties and met eligibility, only 30% met criteria for objective cognitive impairment as measured by the HVLT. This discrepancy highlights the importance of using both tools together as they provide a more complete picture."

After 10 weeks, those in the true acupuncture and sham acupuncture arms showed a clinically meaningful improvement in perceived cognitive impairment as measured by FACT-Cog PCI scores: an improvement of 10.3 points and 10.5 points, respectively, compared to a 4.8 point improvement in the usual care group. Real acupuncture also showed a two-fold improvement in reducing perceived cognitive impairment compared to usual care at both 10 weeks and 26 weeks, while the difference between real and sham acupuncture was not significant at any time point.

"The fact that real acupuncture and sham acupuncture had similar effects on improving perceived cognitive function may be because although sham acupuncture does not stimulate the body in the same way, it still provides benefits such as personal attention, relaxation and the feeling of being cared for, all of which can improve people's feelings," Mao explained.

While real acupuncture improved HVLT scores, sham acupuncture had no difference in objective perceptual function. At week 10, real acupuncture was significantly better than sham acupuncture, with a 4-point difference in HVLT scores. Overall, real acupuncture and usual care showed similar results in improving objective cognitive function. However, in the subset of patients identified as having impaired objective cognitive function at baseline, real acupuncture was associated with a promising trend in memory improvement compared to usual care and sham acupuncture.

"Previous research using brain scans in people with memory problems or pain suggests that real acupuncture may more effectively stimulate certain areas of the brain involved in memory, attention and learning," Mao explained. "While our study also shows that acupuncture needles may have a potential benefit in improving objective cognitive function in people with some impairment, future studies are needed to specifically confirm this."

Adverse events were mostly mild and limited to the acupuncture arm proper, with bruising being the most common (3.1% of participants). Outside of acupuncture, the study also found that insomnia was significantly related to objective cognitive performance and that sleep fragmentation - the number of awakenings and time to wake up - was significantly associated with poorer performance on objective cognitive tests.

“Cognitive difficulties for women with breast cancer are complex and require finding ways to manage both the burden associated with perceived cognitive ability and objective functioning,” Mao said. "While this study has shown that acupuncture's ability to improve a patient's perceived cognitive difficulties is likely due to the process of acupuncture treatment rather than specific needle techniques, it still makes sense for women with breast cancer to try a course of acupuncture to see if it can help improve their sense of cognitive difficulty. This may also benefit objective cognitive function, but we hope to see future studies with larger samples of patients with objective cognitive impairment." will provide more conclusive evidence.”

Limitations of this study include a small sample of patients who met criteria for objective cognitive impairment at baseline. The study was also conducted at a single, large, urban academic cancer center and limited participants to female breast cancer survivors, so the results may not be generalizable to male survivors, survivors with other cancers, or survivors in community or rural settings. The study was conducted during the COVID-19 pandemic, which may have introduced other variables related to a patient's stress and care.

This study was funded by grants from the National Cancer Institute and the National Institutes of Health Cancer Center Support Grant. Mao says other work will receive funds from Tibet Cheezheng Tibetan Medicine Co., Ltd. and Zhongke Health International LLC. He is also the co-founder of Greatly Health.

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