It is believed that qi changes throughout the whole process of malignant tumors. Tumour formation is induced by qi constraint in the early stage， qi sinking is the core disease mechanism after tumour surgery， qi counterflow is an important disease mechanism for nausea and vomiting related symptoms in chemotherapy stage， and qi deficiency is the main pathology in recurrence and metastasis stage. It is proposed that the therapeutic principle of “regulating qi with changes” discussed in Miraculous Pivot-Wei Qi Disorder （《灵枢·卫气失常》） should be implemented in traditional Chinese medicine （TCM） pattern identification and treatment of malignant tumours， modifying the treatment with changes， and regulating qi with corresponding methods： for qi constraint， it should soothe to eliminate the tumour by the method of rectifying qi to resolve constraint， with treatment as Shugan Jianpi Formula （疏肝健脾方）； for qi sinking， it should raise to lift up postoperative viscera by the method of boosting qi to raise sinking， with treatment as Shengxian Decoction （升陷汤） from Records of Chinese Medicine with Reference to Western Medicine （《医学衷中参西录》）； for qi counterflow， the method of moving qi and direct counterflow downward will be used to dissipate the accumulated medicinal toxicity， and patients with retention of medicinal toxicity in the middle jiao and ascending counterflow of stomach qi treated by Xuanfu Daizhe Decoction （旋覆代赭汤） from On Cold Damage （《伤寒论》）， patients with middle yang deficiency and turbid ying failing to descend treated by Wuzhuyu Decoction （吴茱萸汤） from On Cold Damage （《伤寒论》） ； for qi deficiency， it should tonify to prevent the tumor toxin from spreading by the method of boosting qi to resolve toxins， treated by Fuzheng Jiedu Formula （扶正解毒方）.

Based on the theory of “chuanshe”， this paper expounded the role of yang deficiency and toxic knot as the core pathogenesis in various aspects of gastric cancer recurrence and metastasis after surgery， and put forward the prevention and treatment ideas of recurrence and metastasis of gastric cancer by conjugating yang to curb the trend of “transmission （chuan）”， protecting the yang to prevent metastasis by settling its “residence （she）”， preventing immersion by warming the yang to block the way of “chuan-she”， and attacking and cutting to clear the pathogen of cancer and poison and eliminate the root of the disease. In the process of preventing and treating recurrence and metastasis after gastric cancer surgery， the three methods of conjugating yang， protecting yang and warming yang should be flexibly used based on the principle of treating yang； combined with attacking and removing cancer poison， differentiating syndromes and diseases ； meanwhile， the changes of cold and heat in the body should be identified in detail and treated by the syndromes， in order to provide reference for the clinical differentiation and treatment of recurrence and metastasis after gastric cancer accurately.

It is believed that the occurrence and development of squamous cell carcinoma （SCC） is closely associated with inflammatory responses. The theory of fire and heat， advocated by LIU Wansu， provides significant clinical guidance for understanding the pathogenesis and treatment of SCC. Based on this theory， the pathological mechanisms and clinical characteristics of SCC at different stages were analyzed. In the precancerous and early stages， the primary pathogenesis is qi stagnation leading to internal generation of constrained heat； in post-surgery， the condition shifts to qi deficiency with latent yin fire； during the treatment phase， the pathogenesis involves accumulation of pathogenic factors， excess toxins， and severe heat toxicity； in the late stage， the main pathology is yin deficiency with toxic heat， and phlegm-stasis obstruction of the internal organs. Corresponding stage-based treatment strategies are proposed. In the early stage， regulating qi movement to dissipate constrained heat； for post-surgery， tonifying qi and raising yang to dispel latent fire； during treatment stage， clearing heat and detoxifying to eliminate cancerous toxins； and in the late stage， nourishing yin and unblocking the bowels to clear deficiency heat.

ObjectiveTo explore the distribution characteristics of traditional Chinese medicine （TCM） syndromes in postoperative gastric cancer patients， and to analyse the factors associated with yang deficiency syndrome and its severity. MethodsTotally， 173 patients who underwent postoperative gastric cancer surgery and were treated in four centers nationwide from February 22， 2022 to March 21， 2023， were enrolled. General information and TCM syndromes were collected， and Diagnostic Scale for Yang Deficiency Syndrome in Gastric Malignancies was filled in. The frequency of TCM syndromes after gastric cancer surgery was analyzed， and univariate analysis and multivariate logistic regression analysis were performed on the related factors of yang deficiency syndrome versus non-yang deficiency syndrome and between different severity of yang deficiency syndrome. ResultsThe most common syndrome after gastric cancer surgery was qi deficiency （95 cases， 54.91%）， followed by yang deficiency （87 cases， 50.29%）. Patients with yang deficiency syndrome were often suffered from qi deficiency， qi stagnation， and phlegm dampness syndrome. Comparing yang deficiency syndrome with non-yang deficiency syndrome， univariate analysis showed that history of alcohol consumption， pathological stage， degree of differentiation， Lauren grade， signet ring cell carcinoma， vascular cancer thrombus， and nerve invasion were statistically significant （P＜0.05）； and multivariate logistic regression analysis showed that history of alcohol consumption， signet ring cell carcinoma， pathological stage Ⅲ， Ⅳ， and vascular cancer thrombus may be correlated with yang deficiency syndrome in postoperative gastric cancer patients （P＜0.05）. The univariate analysis showed that age， pathological stage， precancerous lesions， and body mass index grade were significantly different when compared between mild and severe yang deficiency syndrome （P＜0.05）； multivariate logistic regression analysis showed that age， low body weight， and pathological stage Ⅲ and Ⅳ might be correlated with severe yang deficiency syndrome after gastric cancer surgery （P＜0.05）. ConclusionQi deficiency and yang deficiency are common TCM syndromes in postoperative patients with gastric cancer. Alcohol consumption history， pathological staging （stage Ⅲ and Ⅳ）， signet ring cell carcinoma， and the presence of vascular cancer thrombus may be correlated with the occurrence of yang deficiency syndrome， and higher age， low body weight， and pathological staging （stage Ⅲ and Ⅳ） may be the correlates of severe yang deficiency syndrome.

"Stagnation" is an important pathological state in the development and progression of malignant tumors. However， its intrinsic connection with different stages of tumor evolution has not been clearly elucidated in previous studies. Drawing on clinical practice， this paper proposes the theory of stagnant toxin， emphasizing stage-specific pathogenesis and differentiated treatment strategies for tumors based on the varying manifestations of stagnation at each phase. The theory interprets the pathogenesis of stagnant toxin across the stages of tumor development through the five elements "wood， fire， earth， metal， and water" corresponding respectively to wood stagnation in the precancerous stage， metal stagnation in the postoperative phase， fire stagnation during adjuvant therapy， earth stagnation in the progressive stage， and water stagnation in the advanced stage. Each type of stagnation reflects a distinct pathogenic mechanism， such as wood stagnation giving rise to disease， metal stagnation inducing residual symptoms， fire stagnation resulting in ulceration， earth stagnation spreading toxin transmission， and water stagnation leading to critical deterioration. Accordingly， the treatment principles include guiding wood stagnation with counterflow， dispersing metal stagnation to harmonize symptoms， venting fire stagnation to regress ulcers， depleting earth stagnation to block progression， and controlling water stagnation to preserve vitality. This theoretical framework offers a traditional Chinese medicine perspective for understanding and treating malignant tumors based on the concept of stagnant toxin.