http://www.amazon.com/Cancer-Diet-Understanding-Metabolic-Origin-ebook/dp/B00SDQ49ZK/ Dr. Kevin Buckman - Modified nucleosides are not reused by cells and ultimately are excreted by the body. Increased urinary levels of modified nucleosides have been detected in numerous cancer studies. Increased levels of urinary sarcosine have been observed in prostate cancer patients and were shown to be increased during prostate cancer progression and proliferation. The prostate cancer study also showed that introduction of sarcosine induced a malignant phenotype. Fatty acid synthesis has been known to be increased in tumors and lipids are involved in many tumor activities of all kinds (migration, dissemination, duplication). Choline, phosphocholine, phosphatidylcholine, and glycerophosphocholine are needed for cell wall synthesis and are increased in brain, breast, prostate and liver cancers. Lysophosphatidylcholines (lysoPCs) are lipid intermediates that can used to form PCs or are the products of phospholipases acting on PCs. Decreased blood levels of lysoPCs have been observed in lung and liver cancer while lysophosphatic acid has been reported as increased in ovarian cancer. Tissue levels of phosphoinositides have been increased in several tumors and three phosphatidylinositols in plasma were found to be reduced in pancreatic cancer. There are thousands of these metabolic activities going on with cancer. The analyses of lipids have shown that they play a significant role in tumor metabolism, growth, and signaling and are an important part of cancer studies about the role of fats, both good and bad. Glucose has another role, foods with hormones that favors cancer growth are just some of many examples of the metabolic nature of cancer.