Table 1. Patient demographics and clinical profiles.

Variables	Discovery phase				Validation phase
	MPE (n=3)	HC (n=3)	P value		MPE (n=54)	BPE (n=33)	MT (n=50)	HC (n=46)
Age, yr, mean ± SD	78±3	63±8.89	0.051		61.87±13.13	59.82±13.61	62.02±13.24	55.80±14.38
Gender			0.083
Male	2	0			28	22	30	19
Female	1	3			26	11	20	27
Smoking			0.273
Smoker	1	0			27	13	23	27
Non-smoker	2	3			27	20	27	19
Histology type
Adenocarcinoma	3				26		20
Squamous cell carcinoma	0				9		11
Small cell lung cancer	0				12		19
Malignant mesothelioma	0				7		0
Parapneumonic effusion						12
Tuberculous pleural effusion						9
Connective tissue disease						6
Transudative pleural effusion						5
Pulmonary embolism						1

MPE, malignant pleural effusion; BPE, benign pleural effusion; MT, malignant tumor without pleural effusion; HC, healthy control.