1. Stages of Cancer
The progression of cancer--skin cancer included--is organized by stages. Doctors use stages 0, I, II, III and IV to describe how invasive a person's cancer has become. These stages help doctors and health care providers to communicate easily the extent that the cancer has invaded the body. Once the doctor has gathered enough information to fit your disease into a stage he will decide how to treat you. Doctors use the stages of cancer to help determine a treatment plan
2. Breslow's Thickness and Microscopic Ulceration
Skin cancer is defined as the abnormal growth of skin cells. These cells grow at a rapid rate--much faster than your healthy skin cells--and create tumors inside the layers of your skin. One of the measurements physicians use to learn more about your cancer is Breslow's thickness, which measures the thickness of the tumor. This measurement is taken by measuring the distance between the upper layer of the epidermis (the outermost layer of the skin) and the deepest point that the tumor reaches. This information will be used in staging your cancer. Another factor to consider when evaluating the stage of melanoma is microscopic ulceration. Microscopic ulceration means that the epidermis covering the tumor has microscopic tears and cuts in it. If microscopic ulceration is found, it may mean that your cancer will be staged later and more aggressive treatments may be considered.
3. Clark's Level of Invasion
Doctors cannot determine the stage of your cancer by looking only at Breslow's thickness and microscopic ulceration.
Another piece of information that doctors need to know as they try to determine what stage your cancer is in is Clark’s level of invasion. Because the skin is made up of many different layers, it's important to find out how many layers of skin the tumor is effecting. Clark's level of invasion is organized from level 1, where the tumor is only involving the epidermis, to level 5, where the tumor is involving the subcutaneous fat, which is the layer of fat under your skin. The higher the level, the more invasive the tumor has become. Remember, your level of invasion is used to help determine your stage. Your level of invasion and stage are different numbers.
4. Sentinel Node and Staging
Cancer begins at a primary site and can spread to other parts of the body, usually through our lymphatic system. The lymph system acts as a "highway" for cancer cells, allowing them to travel from one region of the body to another. Once cancer has spread to your lymph nodes, it is important to determine if the disease has settled anywhere else in the body.
Because cancer can spread through the lymphatic system, your physician may want to remove your sentinel node. Your sentinel node is the lymph node closest to the primary tumor and is the most likely first place for the cancer to spread. Once the sentinel node has been removed it can be tested in a laboratory for cancer cells. If there are melanoma cells present in the sentinel node, there is a chance that other lymph nodes surrounding the area and throughout the body have also been infected. A number of those nodes will then be removed for careful study. If the sentinel node is negative for melanoma cells, then the surrounding lymph nodes will usually not be removed. The information collected by biopsies performed on the lymph nodes will help the physicians stage your melanoma correctly.
5. Each Stage Requires Different Treatment
When all of the information is put together, the doctor will provide you with information regarding what stage of skin cancer she believes you are in. Stage 0 is also called in situ melanoma, when the disease is only in the epidermis and has not begun to spread to other layers. The only treatment you will need if your cancer is found at this stage is surgery to remove the tumor. This stage has the best chance of a full recovery. If you have been diagnosed with skin cancer at stage I through IV, your disease is more serious. With each increasing stage, the cancer is more invasive to other body systems and therefore more serious. Tumors staged here are invasive and can spread. A stage I cancer is considered a small tumor that is well localized. This stage has a very successful treatment rate. A stage IV cancer has spread to other organs--lungs, liver and bone are likely. The treatment for a stage IV skin cancer will be much more invasive and difficult.
