Table 2. LPA concentration in pleural effusion of lung cancer patients.

Clinical variables	No. of patients	LPA (μg/L), mean ± SD	P value
Age (years)			0.41
≥60	56	20.68±9.30
<60	38	21.20±7.84
Gender			0.789
Male	55	21.87±8.10
Female	39	22.48±9.63
Smoke condition			0.838
Smoke	47	22.27±8.03
Non-smoke	47	21.90±9.44
Histologic type			0.603
Adenocarcinoma	74	22.01±9.28
Squamous cell carcinoma	12	20.76±4.65
Small cell lung cancer	8	24.75±8.19
Cytologic examination			0.234
Positive	28	24.10±11.68
Negative	66	21.23±11.68

LPA, lysophosphatidic acid.