First things first: What is cancer?

Characteristics of Cancer Cells:

Before I discuss prostate cancer, I am going to talk a little bit about what cancer is. This is a very broad topic, so I will try to make it as brief as I can. There are over 100 different types of cancer, so when someone says they have "cancer," they likely have something different than another person who has "cancer." This is because different types of cancer are unique. Simply put, cancer is a very broad term that refers to cells in your body that grow and act differently than your normal cells would. They are cells that have changed from normal cells due to changes in their DNA, which is the genetic information that tells every living cell how it should live/what it should do. Cancer cells function abnormally and thus cause harm to the body. While different types of cancer vary in where they grow, how they affect a patient's survival rate, and more, cancer cells have several specific characteristics in common that help them survive in our bodies. I am going to mention just a few of them:

1) They can keep multiplying over and over again. In other words, they are "immortal." Normal cells in the body receive special messages that tell them when to stop dividing and/or to die. This is healthy because if any cell keeps on dividing, there is a greater chance that it can mutate into something it shouldn't be because there are more chances for a random error to happen. It is also good because if a cell becomes "sick" in our body, these signals will cause it to self-destruct so that the rest of our cells are protected from it. However, cancer cells are actually able to ignore these signals! They can keep on growing and growing.

2) They can recruit nutrients (good things in our body such as vitamins that help us grow and stay healthy) by creating pathways for blood to flow to them. This is called "angiogenesis." Nutrients pass through the blood stream before they are delivered to our bodies' cells, and cancer cells selfishly find ways to steal them for themselves so that they can keep growing and become harder to kill.

3) They can often actually escape destruction from our immune cells, the cells that fight bad cells, viruses, bacteria and other germs in our bodies. In other words, cancer cells are sneaky and hard to kill.

Cancer Staging

There are several different tools used to stage cancer. The first one I am going to discuss is Summary Staging. Many cancer registries use this type of staging. Here it is:

Stage 1- In Situ: 

In this stage, the abnormal cells exist only in the layer of cells they originated/started growing in.

Stage 2- Localized: In this stage, the cancer is limited to the organ or tissue it started growing in and there is no evidence that it has spread beyond it. Examples of organs are the skin, colon, liver, lung, prostate, etc.

Stage 3- Regional: In this stage, the cancer has moved from the primary site it was once contained within and it has now spread to nearby lymph nodes or other organs or tissues in the body. If cancer cells get into lymph nodes, they can travel throughout lymph, an important fluid that travels throughout our bodies. This makes it easier for cancer cells to spread to other parts of the body, which we really do not want to happen.

Stage 4- Distant: In this stage, the cancer has moved from its primary location to distant organs, tissues, or lymph nodes. 

Another common method of staging is TNM staging, which looks at the extent of the Tumor, if cancer cells have spread to nearby lymph Nodes, and if it has spread ("Metastasized") to distant areas (side note: a tumor is a mass of abnormal cells. These cells might be cancerous or they might not be; Remember, cancer cells are defined by being cells that no longer perform normally. A tumor may also have abnormal cells that still keep some of their normal functions, therefore they are not considered cancerous, although they have the potential to be in the future.) There are 5 stages in the TNM staging: 0, I, II, III, or IV (0, 1, 2, 3, 4). 0 Means the tumor is "in situ," which I defined earlier, and 4 means it is metastatic (it has spread distally/far in the body).

Sources:

American Cancer Society (2014, December 22). What is Cancer? Retrieved from http://www.cancer.org/cancer/prostatecancer/detailedguide/prostate-cancer-what-is-cancer

Huether, S., & McCance, K. (2008). 9. In Understanding pathophysiology(4th ed., pp. 222-252). St. Louis, Mo.: Mosby/Elsevier.

Reding, Kerryn. (PhD, MPH, Lecture director) (October 2014). Neoplasia. Lecture conducted from the University of Washington School of Nursing, Seattle.