A method of detecting ovarian cancer in a female test subject comprising determining the amount of plasmenyl-PA or a biomarker having a mass charge ratio of approximately 655.3 in a sample of a bodily fluid taken from the female test subject and comparing the amount of plasmenyl-PA (or the biomarker) in the sample of the bodily fluid taken from the female test subject to a range of amounts of plasmenyl-PA (or the biomarker) found in samples of bodily fluids taken from a group of normal female subjects of the same species as the female test subject and lacking ovarian cancer, whereby a lower amount of the plasmenyl-PA (or the biomarker) in the sample of the bodily fluid taken from the female test subject indicates the presence of ovarian cancer.