The maintenance effect of acupuncture on breast cancer-related menopause symptoms: a systematic review

This systematic review and meta-analysis investigated a crucial aspect of acupuncture in the treatment of menopause-related symptoms in women with breast cancer: how long the benefits persist after the end of treatment. The question is especially relevant for this population, which often develops severe menopausal symptoms due to oncologic treatments such as chemotherapy and hormone therapy but has limited options for relief, since traditional hormone replacement can interfere with cancer treatment.

The researchers analyzed 13 randomized controlled trials that included 943 women, following rigorous guidelines (PRISMA) to ensure methodologic quality. The studies varied in their control groups, including sham acupuncture, usual care, applied relaxation, and hormone therapy. The mean age of the participants was 56 years, with sample sizes ranging from 38 to 190 participants. Follow-up ranged from 3 months to 2 years after the end of acupuncture treatment.

The results revealed an interesting and clinically significant pattern. For general menopausal symptoms, measured by the Kupperman Index (which assesses 11 items including hot flashes, night sweats, sleep disturbances, irritability, depressed mood, dizziness, general weakness, joint pain, headache, palpitations, and paresthesias), acupuncture demonstrated a significant maintenance effect for at least 3 months after the end of treatment (p = 0.001), with a mean reduction of 3.47 points on the scale.

However, when hot flashes were analyzed specifically — both in frequency and intensity — there was no significant maintenance effect at 3 months (p = 0.29 and p = 0.34, respectively). This distinction is important: although acupuncture does not maintain lasting effects on hot flashes, it appears to have a sustained impact on other aspects of the climacteric syndrome, such as sleep disturbances, arthralgia, headache, and neurovegetative symptoms.

The mechanistic explanation for these findings may lie in the different pathways through which acupuncture acts. For hot flashes, the mechanism may be more related to modulation of neurotransmitters such as serotonin and norepinephrine in the hypothalamic thermoregulatory center, effects that may be more transient. For other menopausal symptoms, acupuncture may act through modulation of the autonomic nervous system and release of endorphins, providing longer-lasting benefits for pain, anxiety, and sleep disturbances.

Importantly, no adverse events were reported in the included studies, reinforcing the safety profile of acupuncture. This is particularly relevant for women with breast cancer, who often already cope with multiple side effects of oncologic treatments.

The clinical implications are significant. The results suggest that acupuncture may be a valuable therapeutic option for women with breast cancer who experience menopausal symptoms, especially given the limitations of hormone therapy in this population. The 3-month maintenance effect also has practical implications for treatment planning, suggesting that booster sessions every 3 months may be a cost-effective strategy.

Limitations of the study include heterogeneity in the acupuncture protocols used, variation in control groups, and reliance on subjective self-reported measures for symptoms such as hot flashes. In addition, there was significant heterogeneity between studies (I² = 67% for hot flashes and 76% for menopausal symptoms), indicating variability in results.

This pioneering review on acupuncture maintenance effects provides important evidence to guide clinical practice and future research, establishing that the benefits of acupuncture extend beyond the active treatment period.