Cancer Staging and Grading
Now that you understand Cancer Types, let’s take a look at Cancer Staging and Grading. Cancer Staging is a system that describes the extent of damage cancer has done to the body – how far it has grown and spread. Understanding cancer staging is essential as effective treatment can only be suggested if stage of your cancer is known. Cancer staging also helps determine patient’s prognosis (outlooks). As a general rule, earlier stages and lower grades of cancer increase patients outlooks. In order to better understand cancer staging and grading, we first must take a closer look at how cancer grows and spreads:
Cancer Growth and Spreading
As you remember from What is Cancer lecture, cancer starts with one cell the genetic structure of which gets altered due to mutations. The progress of gene’s mutations could develop into uncontrolled growth of abnormal cells resulting in formation of a tumor. In order to better understand cancer staging and grading, we must first take a closer look at three stages of tumor development and progress:
Growth of Tumor
Cancer cells multiply at a high rate. Overtime, they form into a lump that is caller “a tumor”. Tumor is literally a mass of tissue made up entirely from cancer cells. As the tumor grows, cancer cells within release chemicals that cause imbalances in surrounding blood vessels until they branch off to supply tumor with blood. This is referred to as angiogenesis. This newly obtained blood supply delivers oxygen and nourishment to the cancer cells, allowing the tumor to grow. Without this ability, a tumor would not grow larger than the size of a pin head, but with supply of blood, cancer cells will continue to divide and push through surrounding tissue which causes damage to these (normal/healthy) cells.
Spread of Tumor to Lymph Nodes
As a tumor continues to grow, some of the cancer cells may enter lymph nodes – glands found all over the body where pathogens and germs are filtered. Lymph nodes are an important part of overall immunity as they also contain white blood cells. Cancer cells may enter lymph nodes through a network of lymph channels and start multiplying there, developing into a secondary tumor. Test results from lymph nodes are therefore an important factor in determining cancer staging.
Metastasis
When cancer cells get into blood vessels, they get carried to other parts of the body and may start multiplying there, creating secondary tumor at the new location. This process is called metastasis.