Fatty acid composition of lysophosphatidic acid and lysophosphatidylinositol in plasma from patients with ovarian cancer and other gynecological diseases

Objective. We previously reported that plasma levels of total lysophosphati dic acid (LPA) represented a potential biomarker for ovarian cancer and oth er gynecological cancers [1]. However, total LPA is composed of different L PA species with distinct fatty acid chains. The major objective of the curr ent study, therefore, was to determine whether one or more specific fatty a cid LPA species was associated with disease or disease staging. If this was determined, these species could be useful in further improving the sensiti vity and/or specificity of this biomarker for the diagnosis and/or prognosi s of the disease. Because lysophosphatidylinositol (LPI) comigrates with LP A, this study represents the analysis of combined molecular species from bo th lysolipid classes. Methods. The patient population, sample collection, and analyses have been reported previously [1]. Lipids were hydrolyzed from the LPA band on thin-l ayer chromatography plates. The following individual fatty acid species wer e analyzed by gas chromatography: palmitic acid (16:0), stearic acid (18:0) , oleic acid (18:1), linoleic acid (18:2), arachidonic acid (20:4), and doc osahexaenoic acid (22:6). The LPA/LPI fatty acid composition levels were an alyzed and compared with disease status. Results. Distinct plasma LPA/LPI fatty acid chain species were not associat ed with ovarian or other gynecological cancers, compared to patients with b enign gynecological disease or healthy controls. However, an increased pres ence of unsaturated fatty acids in plasma LPA/LPI was found in patients wit h late-stage or recurrent ovarian cancer and possibly with other gynecologi cal cancers. Conclusions. Analysis of individual fatty acid species present in plasma LP A/LPI do not appear to enhance the sensitivity or specificity of total LPA/ LPI as a marker for gynecological cancer detection. However, our results su ggest that increased LPA/LPI species with unsaturated fatty acid chains may be associated with late-stage or recurrent ovarian cancer. (C) 2001 Academ ic Press.