Despite increased awareness of cancer's causes and predisposition, preventive measures and risk reduction are not 100% effective at avoiding cancer. The key to success in treating cancer is early detection. Unfortunately, symptoms of cancer may be evasive, are often non-specific, and may be dismissed or attributed to other common ailments, aging, diet, and lifestyle. Such vague symptoms may include fatigue, loss of appetite, weight loss, transient pain, and change in bowel regularity. Tumors may be growing undetected and may not cause detectable symptoms for many years in some individuals. Aggressive tumors may even begin to metastasize before the cancer is detected.
When the body fails to alert individuals of a looming problem, the need for a reliable and sensitive tumor marker becomes evident.