Table 4. CA15.3 in serum and pleural effusions.

Sample population	n	Mean	Median	Positive (%) (>53 U ml−1)	Significance levela
Serum
Mesothelioma	49	100±189	47	17 (35%)
Normal	24	21.5±9.7	21	0	P<0.0001
Asbestos-exposed benign disease	32	52±34	38	9 (28%)	ns
Benign effusions	11	34±26	32.6	1 (9%)	P=0.016
Effusion
PE mesothelioma	51	69±107	24	17 (33%)
PE benign	30	10±10	8.5	0	ns
PE malignancy	25	66±112	24	7 (28%)	P=0.004

^aLevel of significance relative to samples from patients with mesothelioma.