Many people incorrectly believe that cancer is caused by one or two occurrences that transpire within the lifetime of an individual. This is not so. For a human being to acquire cancer, many factors are involved. Using phase 1(in vitro studies), phase 2(small animal studies), and phase 3(studies using humans) trials specific events have been identified as trigger factors for the incidence of tumors. However the individuals must have had a predisposition towards cancer to begin with. For example, in large pharmaceutical companies, the cell lines experimented with are usually derived from individuals that have specific treatable and untreatable cancer cells. The advantage to using cell lines which are carried from biopsies of cancer patients is many fold. These cell lines don’t die after 50 generations, as do cell lines derived from normal patients. Additionally, cancer cells don’t adhere as tightly to the petri dish in in vitro studies, and they round up, allowing for more cells to be fit on a plate than normal.
Every day life can now be more enjoyable to people who believe that cancer is a multi-hit process. For example, in the summer time, people who get too much sunlight don’t have to worry about acquiring melanoma right away. They would have to be over-exposed to sunlight for a relatively long period of time; or they would have had to engaged in other cancer-causing activities such as cigarette smoking to suffer from cancer. That’s why injury attorneys take cases from clients who claim to have gotten cancer from working with asbestos, even if the clients are smokers. Because maybe a light smoker wouldn’t have been afflicted with lung cancer if they had been able to live an otherwise cancer-free life. But, the exposure to asbestos may have augmented the deleterious affects of smoking; and therefore this asbestos exposure may have actually been the triggering event for cancer of this particular cancer, rather than the light smoking. This is why the personal injury attorney would be inclined to take this case.
So far we have discussed environmental factors that act together; and ultimately lead to cancer. However, there are are also multiple genetic factors that prove to be cancer causing. As you probably have read by now, normal DNA sequences, proto-oncogenic in nature, may be cleaved to produce oncogenes, and as such encode proteins which are believed to play a role in causing cancer. However, these proteins themselves do not cause cancer themselves. They act together with other genetic or environmental events to produce malignant tumors.