There’s a huge body of evidence demonstrating that all of the cells within a tumor mass are derived from a single cell. Imagine; one damaged cell may result in a life-threatening tumor. The size of the real meaning behind this is hard to grasp because it’s a very shocking and frightening revelation.
Although all the cells within a tumor mass could be derived from a single cell, this doesn’t mean that all of the cells in a tumor are genetically indistinguishable like you may expect. Tumor cells are more unstable than normal cells, meaning that they mutate at a significantly higher rate and they fix themselves much less efficiently. Therefore, the cells within a tumor are distinct even from one another. Fortunately, the series of events resulting in one cell getting a cancerous tumor comprising millions of its own offspring is an uncommon event.
Actually, it isn’t only one event that causes this, but many events that have to occur in a certain sequence. First, a bit of the DNA strand has to be significantly mutated (we’ll discuss how this could happen later) and the mutations must slide through the repair mechanics. These mutations may occur over generations of cells. For instance, one generation might have one mutation; another may have no.
A subsequent generation may have yet another and so on, until the “cancer mutations” have happened. Because of these mutations, the mobile must achieve the capacity to proliferate (divide rapidly) and consequently lose its normal function. In a sense, the significant use of the cell has to be to split. There are probably only a restricted number of alterations which will enable a cell to lose its capabilities and divide out of control. Some alterations affect nothing, others can cause a minor change that’s not really threatening to the mobile, and still others can outright kill the cell.
So, to become cancerous, the cell has to maintain its ability to divide without causing any damage to restrict its capacity to survive. If a cell becomes bent on dividing, the mobile will only continue dividing and crowd out other cells within the region. In some fortunate cases an individual’s own immune system might actually block the growth of the tumor. The immune system may recognize the cells within the tumor aren’t normal. If this occurs, the immune cells will then have a simple time destroying the tumor.
This may take place lots of times throughout someone’s life without them being affected. If a tumor goes unnoticed and starts to grow, a lack of nutrients can eventually limit its development. If nutrients aren’t continuously provided, the tumor cells can’t metabolize. In cases like this, at the very least, no new growth can occur. If a tumor becomes unable to grow and not able to support some of its functions and cell death occurs, the tumor may go into a dormant state. In this case it can’t spread.
This is known as carcinoma “in situ”, which means “in place”. Once the tumor reaches this limiting size, (which is no larger than a pea), and if it’s not able to get more nutrients, it is going to remain in this dormant state and might eventually die off. Autopsies have shown that 40 percent of women in their 40’s have these miniature”in situ” tumors (not effective at spreading) within their breasts. Had some of those females lived longer, they could have developed breast cancer if they were elderly.
However, a number of these girls would not develop cancer. The little tumors wouldn’t have been able to find the essential nutrients to grow any bigger. A tumor in this situation can’t do any damage. It is going to usually just die off. An individual may actually have several of those stationary, “in situ” tumors and live to a healthy, old age, completely unaffected by the tumors. Researchers are attempting to develop tests which will determine whether someone’s breast and prostate tumors will stay dormant or spread. In that manner, patients in the future could be spared unnecessary therapies.