Therapeutic efficacy of acupuncture point stimulation for stomach cancer pain: a systematic review and meta-analysis

Pain associated with stomach cancer represents one of the major concerns in modern cancer care. Gastric cancer is the fifth most prevalent cancer worldwide and the third leading cause of cancer-related death. Among patients with solid tumors, the incidence of clinically significant chronic pain ranges from 15% to over 75%, dramatically impacting patient quality of life. This pain arises mainly from two sources: directly from tumors (approximately 75% of cases) and as a consequence of anticancer treatments such as surgery, chemotherapy, and radiation therapy (about 25% of cases).

The complexity of cancer pain management, compounded by the current opioid crisis, has directed medical attention toward nonpharmacological therapeutic approaches. In this context, traditional Chinese medicine, particularly acupuncture point stimulation, emerges as a promising alternative that has been gaining increasing recognition in the field of cancer pain treatment.

This pioneering study aimed to systematically evaluate the efficacy and safety of acupuncture point stimulation in the treatment of gastric cancer pain. The researchers conducted a comprehensive systematic review and meta-analysis, searching seven major scientific databases, including PubMed, Web of Science, Cochrane Library, Embase, and Chinese databases such as WANFANG, CNKI, and VIP, covering publications from database inception through July 2023. Only randomized controlled trials investigating acupuncture point stimulation — encompassing traditional acupuncture, electroacupuncture, moxibustion, and acupoint injection — for the treatment of patients with gastric cancer pain, with no language restrictions, were included. The methodological quality of the studies was assessed using the Cochrane Risk of Bias tool, and the results were synthesized through meta-analysis using fixed- or random-effects models depending on heterogeneity between studies.

The study protocol was registered in PROSPERO under number CRD42023457341, ensuring transparency and methodological rigor.

The final analysis included 11 randomized controlled trials, encompassing 768 patients with gastric cancer and associated pain. Of these participants, 406 received acupuncture point stimulation while 372 were in the control group with conventional medication. The results demonstrated significant and consistent benefits of acupuncture treatment. The efficacy rate was markedly higher in the acupoint stimulation group compared with the medication control group, with a relative risk of 1.63 and a 95% confidence interval of 1.37 to 1.94.

Regarding pain intensity, measured by the Numeric Rating Scale, there was a significantly greater reduction in the acupuncture group, with a standardized mean difference of -1.30 and a 95% CI of -1.96 to -0.63. The subgroup analysis revealed that acupoint injection showed the best therapeutic results, followed by moxibustion and traditional acupuncture. In terms of safety, acupuncture treatment demonstrated a superior profile, with a lower incidence of nausea and vomiting compared with the groups receiving medication alone. Frequency analysis of acupuncture points showed that Sanyinjiao (三陰交) and Zusanli (足三里) were the most commonly used points, followed by Zhongwan (中脘) and Neiguan (內關).

For patients facing gastric cancer-related pain, these results offer encouraging perspectives on an effective and safe complementary therapeutic option. Acupuncture point stimulation may represent a valuable alternative or complement to conventional pharmacological treatment, potentially reducing dependence on analgesic medications and their associated side effects. For health care professionals, the study provides robust scientific evidence that may guide the integration of traditional Chinese medicine techniques into cancer pain treatment protocols. The identification of the most effective acupuncture points offers practical guidelines for clinical application.

The findings suggest that an integrative approach, combining traditional medicine with conventional treatments, may optimize therapeutic outcomes, providing more effective pain relief with a lower risk of adverse events. This evidence is particularly relevant in the current context of the search for alternatives to opioids for chronic pain management.

Despite the promising results, the study has important limitations that must be considered in interpreting the findings. The considerable heterogeneity among the included studies, evidenced by I² values greater than 50% in some analyses, suggests variability in methodologies and study populations. All included studies were conducted in China, which may limit the generalizability of the results to other populations and cultural contexts. Additionally, some studies had small sample sizes and incomplete data, factors that may influence the robustness of the conclusions.

The inability to adequately blind participants and clinicians, inherent to the nature of acupuncture interventions, represents another significant methodological limitation. Publication bias, evidenced by asymmetry in the funnel plots, suggests that studies with negative results may not have been published, potentially overestimating the observed benefits. These limitations highlight the urgent need for additional, well-designed clinical trials with larger samples and greater geographic diversity to confirm and strengthen the evidence presented. Future studies should also investigate the underlying mechanisms of action and standardize treatment protocols to optimize the therapeutic benefits of acupuncture point stimulation in the management of gastric cancer pain.