Chinese medicine syndromes and stages of early breast cancer: hierarchical cluster analysis and implication for clinical practice

Background: Chinese medicine (CM) has been widely used for women's health, including those with early breast cancer. Contemporary literature varies in descriptions of the CM syndromes that are critical for determining CM treatment options for breast cancer patients. However, the corresponding syndromes have not been standardized to align with the conventional medicine treatment stages. This review aimed to address this knowledge gap to enhance the quality and consistency of CM interventions for early breast cancer patients. Methods: In total, eight Chinese and English language databases were searched, and textbooks and clinical care documents were gathered. Sources were classified according to five treatment stages: preoperative, postoperative, chemotherapy, radiation therapy, and endocrine therapy. Descriptive statistics were used to examine the syndromes, and hierarchical cluster analysis was conducted to investigate clusters of signs and symptoms. Results: The CM syndrome of dual deficiency of qi and Blood was one of the most common syndromes across all treatment stages, whereas lack of strength and lassitude were the most common clinical presentations throughout all stages, except the preoperative stage. Cluster analyses identify three or four syndromes in each treatment stage. Cluster results for the preoperative stage were: Blood stasis, Liver depression and qi stagnation, and Kidney yin deficiency. Dual deficiency of qi and Blood existed at different stages except for the preoperative stage. In the postoperative stage and chemotherapy stages, some symptoms were categorized into clusters that related to the Spleen and Stomach. Syndromes such as yin deficiency with fire toxin and yin deficiency with fluid depletion were unique to the radiation therapy stage. Clusters for endocrine therapy stage included the dual deficiency of Spleen and Kidney, Liver depression and qi stagnation, and Kidney yin deficiency. Conclusions: Systematic review of the contemporary literature for early breast cancer revealed that the most frequently seen CM syndromes and cluster results have some similarities but some important distinctions. Clinical data are needed to confirm whether the syndromes described in contemporary literature reflect those seen in women with early breast cancer.