Cancer may affect people at all ages, even fetuses, but the risk for most varieties increases with age. One of the major problems in dealing with cancer today is that many cancers are symptom-free in their early and mid stages. In certain cancers, such as gallbladder cancer, symptoms often do not start until the disease has reached an advanced stage. A simple blood test may be able to detect the presence of up to 13 common cancers in their early stages. An early detection is needed to initiate treatment in order to effectively get rid of the cancer. As many would know, recurrence of cancer is common as age catches up.