24 Aug What is Cancer?

I was thinking long and hard over the last couple of days, trying to decide what my first real topic should discuss. I was thinking about blogging about Her2Nu, BRCA1 or BRCA2, perhaps genetic counseling, but then it dawned on me, why not start with the most basic thing? Why not start with actually talking about cancer and what it is.
Most of us know someone that has cancer, or perhaps have even had a loved one diagnosed with cancer. We know it can be located in the breast, the prostate, the lung, the colon, the brain, and etc. We hear about it almost on a daily basis in the news, on TV, in a paper, or a magazine article that we read. We all have heard about cancer, but do we all really understand what it is?
Cancer is defined simply as an abnormal growth of cells.
Now all cells divide on a daily basis. Normal cells have “rules” inside of them to limit the number of times the cells split into new cells. This splitting is typically done over a 6 hour period of time. So on any one day, most normal cells in our bodies will divide up to 4 times. Our skin loses cells constantly. We all have eye lashes that fall off daily. So in order for our body to keep up with all of this normal loss of skin, hair, and other such things, it reproduces them by allowing our normal cells to divide and repopulate what we have lost.
Cancer is different. What happens most often times is that there is a “change” or a mutation at a cellular level that creates a problem in the “rules” of how a cell divides. Typically the rule for the number of times a cell can divide is turned off or sped up. This means that a “changed cell” now may divide up to every hour, or 24 times in one day. This is abnormal behavior of cells. Each time that cell divides, it creates new cells that have that mutation, or “change” in the rules of their division.
A scenario would be as such: A single cell has a change or a mutation in it. If that change allows its rule for division to turn off, and allows the cell to divide more quickly, it repopulates itself with more and more of those abnormal cells, thus creating a cancer or a tumor. As more of these cells become abnormal, they seek out more blood supply to continue nourishing the newly formed cells. This allows the cycle to continue. As the cancer seeks more blood, it begins to deprive blood supply to normal tissues. This allows more of the cancer cells to invade normal areas of tissue, such as the breast or prostate, and creates what can be finally detected by normal screening and detection.
Some cancers are very aggressive and grow rapidly with in months. Others such as prostate cancer can take years and years to reach a point in which it becomes detectable. This all relates back to the importance of yearly physicals, exams, screening and detection. The more regular we are about making sure we go to see the doctor once a year for our yearly check ups, the better it is for us if we ever do develop cancer.
Most cancers, if detected early enough, are treatable and curable.
-CancerGeek