Patent ID: 7368254

Claim:
A method for identifying malignant tissue in a mammal, wherein said malignant tissue is a member selected from the group consisting of lung cancer, ovarian cancer and sarcoma tissue, said method comprising: a) administering a lipid-based system comprising a lipid derivative and a label to an individual suspected of having a malignant disease characterised by having an elevated PLA 2 level whereby said label is released from said lipid derivative to the malignant tissue, and b) detecting said label, thereby identifying said malignant tissue, and wherein said lipid derivative constitutes 50-100 mol % of said lipid-based system, and wherein said lipid derivative has the following formula: wherein X and Z are O; Y is —OC(O)—, Y then being connected to R 2 via either the oxygen or carbonyl carbon atom; R 1 is an aliphatic group of the formula Y 1 Y 2 ; R 2 is an organic radical having at least 7 carbon atoms; where Y 1 is —(CH 2 ) n1 —(CH═CH) ni2 —(CH 2 ) n3 —(CH═CH) n4 —(CH 2 ) n5 —(CH═CH) n6 —(CH 2 ) n7 —(CH═CH) n8r —(CH 2 ) n9 , and the sum n1+2n2+n3+2n4+n5+2n6+n7+2n8+n9 is an integer of from 9 to 29; n1 is zero or an integer of from 1 to 29, n3 is zero or an integer of from 1 to 20, n5 is zero or an integer of from 1 to 17, n7 is zero or an integer of from 1 to 14, and n9 is zero or an integer of from 1 to 11; and each of n2, n4, n6 and n8 is independently zero or 1; and Y 2 is CH 3 or CO 2 H; where each Y 1 —Y 2 independently may be substituted with halogen or C14-alkyl, and R 3 is selected from phosphatidic acid (P0 2 -OH), derivatives of phosphatidic acid and bioisosters to phosphatic acid and derivatives thereof.