It’s useful to know how the body normally keeps its cells healthy (Greer, 1999). Your body’s cells don’t just hold standardized genetic information about who you are. They also need to monitor where in your body they are, so they know what their particular job is within that whole community of cells. The cells in your skin, for example, need to know that they are skin cells. They do this partially by checking what cells are around them.
If a cell has its genetic instructions damaged repeatedly, it can lose track of where it is and what job it is meant to be doing. This can happen due to toxic chemicals, radiation, or “free radicals” (chemicals which result from normal body oxidation, and accumulate with age). If a cell is damaged enough to lose track of where it fits in the community of cells, it is then described as more “undifferentiated” looking, and it may start dividing randomly, instead of at the rate needed to replace itself. It could then be described as a cancer cell. Actually, before reaching this stage, genetic damage is usually repaired. This is a possibility not often discussed in oncology (cancer treatment). However, the body is usually capable of repairing genetic damage unless there is some interference or inhibition of the immune response. Psychological depression has been shown to be one factor which inhibits such repair. (Kiecolt-Glaser, 1985).