Fundamentally, cancer is a genetic problem that is either inherited or developed during an individual's lifetime, and cancer biologists have identified many of the genes that are involved in this process. These genes fall into two basic classes: proto-oncogenes and tumor-suppressor genes. In their normal states, a careful balance between these two classes of genes regulates cell growth and division, with proto-oncogenes accelerating cell growth and division and tumor-suppressor genes putting on the brakes. When mutated, proto-oncogenes can become oncogenes, producing too much or too active growth-stimulating product and driving the cell into a frenzy of unregulated division; loss of growth-inhibiting protein arising from mutation of a tumor-suppressor gene can have a similar effect.
Once the cancerous process is underway, a variety of detection options are available. The presence of cancer cell-specific components in the blood or lymph can be used to provide indirect evidence of cancer. Researchers have also ...
