Relationship between traditional Chinese medicine constitutional types with chemotherapy-induced nausea and vomiting in patients with breast cancer: an observational study

BACKGROUND The theory of traditional Chinese medicine (TCM) constitution involves genetic characteristics, psychological factors, organ functions, and many other aspects. Studies have shown that TCM constitution is associated with HLA polymorphisms and has a genetic basis. A large number of Chinese studies have suggested that the clinical evolution of breast cancer may differ among patients with different TCM constitutions. In addition, patients with breast cancer and different TCM constitutions may have different degrees of myelosuppression after chemotherapy. Some studies have revealed that some constitutions may become predictive factors for death and morbidity of some diseases. The study was to investigate the risk factors among TCM constitutions for chemotherapy-induced nausea and vomiting (CINV) in patients with primary breast cancer undergoing chemotherapy. METHODS From September 2008 to January 2014, 612 patients who underwent surgery and chemotherapy for breast cancer in three hospitals in Xi'an, Shanxi province, underwent TCM constitution assessment using the Nine Basic Constitutions in Chinese Medicine Questionnaire before chemotherapy. CINV was monitored during treatments. Patients were asked to complete the Functional Living Index-Emesis (FLIE) questionnaire. The most severe CINV grade during chemotherapy was recorded according to the WHO standard. The relationships between TCM constitutions, CINV, and clinical and pathological characteristics of the cancers were assessed. RESULTS There were no differences in the incidence of CINV among breast cancer patients receiving different chemotherapy regimens, and among patients with different TCM constitutions. The wetness-heat score was an independent risk factor for severe CINV (grade III-IV) (OR = 1.012, 95 % CI: 1.007-1.021, P < 0.001). In-depth analyses of the wetness-heat constitution showed that bitter taste/smelly mouth was an independent risk factor for severe CINV (OR = 1.209, 95 % CI: 1.035-1.412, P = 0.017), as well as progesterone receptor-positive cancer (OR = 1.429, 95 % CI: 1.030-1.981, P = 0.032). Vomiting history was a protective factor against CINV (OR = 0.548, 95 % CI: 0.353-0.849, P = 0.007). CONCLUSION Risk of grade III-IV nausea and vomiting was higher in breast cancer patients with TCM constitution of wetness-heat, especially bitter taste or smelly mouth.