With the conquest of infectious disease in the past century, cancer has become the most feared and least understood of all human disorders. Almost 56 million Americans now living will eventually have cancer, one in four according to present rates. This report states that cancer will strike in approximately two of three families over the year. In the 1970’s there were over 6.5 million new cancer victims; over 3.5 million of these died. At present over 10 million Americans are under treatment for cancer.
The American Cancer Society and the National Cancer Institute have expended vast sums of money for the support of investigations directed toward the uncovering of new insights into the nature of cancer. It is likely that no biological problem has received more attention than that pertaining to cancer. Despite these efforts, there has been no significant breakthrough in the way of a definitive cure for cancer, perhaps because cancer is not a single disorder but a collection of diseases, sharing a number of common characteristics.
Despite the lack of a cure, there is now a clearer understanding of the pathophysiology of cancer at the cellular level, due to technological advances in the fields of biochemistry and molecular biology. Much is still unclear as to the precise mechanisms which are responsible for the process of cell transformation; however, he offered a description of the stages of cancer as follows: 1. an early stage is recognized, called initiation or introduction, which alters the cell, although this does not inevitably lead to the development of cancer.
A long period of latency may follow. 2. The next stage is promotion from the dormant to the visible stage. At this stage, the process of cancer transformation is still reversible. 3. The third step is progression, which leads to an irreversible definitive stage once it has occurred.