Objective To explore the commonly seen traditional Chinese medicine（TCM） syndromes of lung cancers. Methods Databases including CNKI

Wanfang

VIP and SinoMed were searched for literature on TCM syndromes in patients with lung cancers; the literature was screened and selected according to the inclusion and exclusion criteria; data on title

publication year

literature source

disease category

syndrome type and symptoms were extracted to establish a database. Frequency was used to analyze the distribution of common syndromes and the related symptoms of lung cancers. Latern 5.0 software was used to establish the latent structure model of related symptoms based on the LTM-EAST method

and the common syndromes were obtained through comprehensive clustering; factor analysis and system clustering analysis of related symptoms were conducted to infer the potential syndromes by using SPSS 20.0 software; common syndromes were used to define the criteria

and therefore the commonly seen TCM syndromes of lung cancers were obtained. Results A total of 556 papers and 1453 syndrome records were included

involving 54 syndromes and 126 symptoms; the top three syndromes with frequency ≥5% were deficiency of both lung qi and yin syndrome（19.34%）

yin deficiency and lung heat syndrome（10.53%） and phlegm-damp obstructing the lung syndrome（10.25%）

and the most frequent symptoms included cough（73.23%）

fatigue（39.30%）

chest oppression（36.27%）

phlegm with blood（36.06%） and red tongue（34.48%）. Twenty-one latent variables were obtained through latent structure analysis

and nine common syndromes were inferred by comprehensive clustering based on professional knowledge

which were lung qi deficiency syndrome

lung-spleen qi deficiency syndrome

phlegm-damp obstructing lung syndrome

lung-kidney yang deficiency syndrome

yin and yang deficiency syndrome

liver fire invading the lung syndrome

binding of phlegm and stasis syndrome

yin deficiency and lung heat syndrome

and phlegm-heat obstructing the lung. Factor analysis obtained 15 common factors

and further system clustering analysis inferred eight potential syndromes

including deficiency of both lung qi and yin syndrome

qi deficiency and lung heat syndrome

lung-spleen qi deficiency syndrome

qi stagnation and blood stasis syndrome

phlegm-heat obstructing the lung syndrome

lung qi deficiency

liver fire invading the lung

and phlegm-damp obstructing the lung. The criteria was defined according to the symptom characteristics of the commonly seen TCM syndromes

and finally 10 common TCM syndromes of lung cancers were obtained. Conclusion The commonly seen TCM syndromes of lung cancers are qi stagnation and blood stasis syndrome

binding of phlegm and stasis syndrome

phlegm-damp obstructing the lung syndrome

phlegm-heat obstructing the lung syndrome

liver fire invading the lung syndrome

deficiency of both lung qi and yin syndrome

lung-spleen qi deficiency syndrome

lung qi deficiency syndrome

yin deficiency and lung heat syndrome

and yin and yang deficiency syndrome.