Acupuncture for Breast Cancer: A Systematic Review and Meta-Analysis of Patient-Reported Outcomes

Breast cancer is currently the most common neoplasm among women globally, affecting approximately eight million survivors worldwide. Although advances in treatment have provided five-year survival rates between 85 and 90% in high-income countries, patients frequently face significant side effects from treatments such as chemotherapy, radiation therapy, and hormonal therapy. These may include pain, hot flashes, fatigue, sleep disturbances, anxiety, and depression, substantially impacting their quality of life. In this context, complementary medicine, especially acupuncture, has gained attention as a possible tool to alleviate these treatment-related symptoms.

Acupuncture, an ancient practice of traditional Chinese medicine, has been studied as an adjuvant treatment for various symptoms in oncology patients. Although its mechanism of action is not yet fully clarified, it is believed to help with pain control, hot flash reduction, fatigue improvement, and other common symptoms after breast cancer treatment. However, the results of prior studies had inconsistent results, generating uncertainty about its true efficacy.

This study aimed to comprehensively evaluate the effects of acupuncture in women with breast cancer, specifically focusing on outcomes reported by the patients themselves (known as PROs — Patient-Reported Outcomes). To do this, the researchers conducted a systematic review and meta-analysis, searching for scientific evidence in seven databases (three international and four Chinese) through September 2020. Only randomized controlled studies that investigated different acupuncture techniques (such as manual acupuncture and electroacupuncture) in comparison with control groups (sham acupuncture, no intervention, usual care, or medications) for at least four weeks were included. The primary outcomes were quality of life, while secondary outcomes included pain, hot flashes, fatigue, sleep disturbances, depression, and anxiety.

Of the 2,524 studies initially identified, 29 studies representing 33 articles were included in the final analysis, totaling 2,094 patients. Of these, 1,091 patients received acupuncture and 1,003 were part of control groups. The studies were conducted mainly in the United States, China, and Australia, with patients undergoing acupuncture sessions one to two times per week for four to twelve weeks. The results showed significant improvements in the quality of life of patients treated with acupuncture, measured through validated questionnaires.

Specifically, there was improvement in the physical, emotional, and functional well-being of the patients.

Regarding pain, one of the most debilitating symptoms, acupuncture demonstrated significant efficacy in reducing all dimensions evaluated through standardized scales. Patients reported a decrease in both pain intensity and its interference with daily activities. For hot flashes, a common side effect of hormonal therapy, the results were more modest but still showed benefits in the overall hot flash score. Cancer-related fatigue, which affects the majority of survivors, also showed significant improvement with acupuncture treatment.

Additionally, sleep disturbances and anxiety showed important improvements, while effects on depression were not statistically significant.

The clinical implications of these findings are relevant for both patients and healthcare professionals. For patients, acupuncture represents a relatively safe complementary therapeutic option, with minimal reported adverse effects (mainly mild pain at the application site, minor bleeding, or hematomas). The beneficial effects appear to persist even after treatment ends, suggesting long-lasting benefits. For healthcare professionals, especially oncologists and palliative care specialists, these results provide scientific evidence that can guide integrated treatment recommendations.

Acupuncture may be considered as part of a multidisciplinary approach to symptom management, especially when conventional treatments are inadequate or cause additional side effects.

However, it is important to acknowledge the significant limitations of this study. Many of the included studies were small in size, which may limit the generalizability of the results. In addition, approximately one-third of the studies presented high risk of bias due to the difficulty of blinding in acupuncture studies. Heterogeneity among studies, including different acupuncture protocols, patient populations, and outcome measures, also complicates the interpretation of the results.

Another important aspect is that, when compared to sham acupuncture (where needles are inserted at non-specific points), the benefits of real acupuncture were less pronounced, raising questions about placebo effects versus specific effects of the technique.

In conclusion, although this systematic review provides encouraging evidence on the potential benefits of acupuncture for breast cancer treatment-related symptoms, the results should be interpreted with caution. Acupuncture appears to be a promising and safe intervention that may improve various aspects of quality of life in breast cancer survivors. However, the limited quality of some studies and the small sample sizes preclude definitive conclusions about its efficacy. The authors emphasize the need for larger, better-designed randomized controlled studies with long-term follow-up to confirm these preliminary findings.

In the meantime, healthcare professionals should consider individual patient preferences and specific factors when evaluating acupuncture as a complementary therapeutic option in the comprehensive care of women with breast cancer.