“…Some markers classified as tumor associated antigens are produced by various organs and are not specific to cancer but associated with cancer, such as, cancer antigen (CA) 125, CA153, CA199 (Watanabe, 1996;Malati, 2007). Now, levels of pleural effusion CEA, AFP, CA125, CA153 and CA199 have been assayed in many studies focusing on differentiating benign and malignant pleural effusions (Botte et al, 1990;Cascinu et al, 1997;Porcel et al, 2004;Shitrit et al, 2005;Gaspar et al, 2008;Liang et al, 2008). But there is as yet no evidence that PE tumor markers were employed in predicting the cause of MPE.…”