Last night on Late Night with David Letterman, actor Michael Douglas revealed that he is suffering from Stage 4 throat cancer. The actor was diagnosed in early August when he was evaluated for a persistent sore throat and ear pain. Douglas, 65, blames his past history of alcohol abuse and smoking as contributing to the cause of the tumor, which is apparently at the base of his tongue. He has already begun radiation and chemotherapy, which is to go on for at least 8 weeks. This kind of therapy can cause severe soreness in the throat and difficulty swallowing. Sometimes patients need to have a feeding tube put into their stomach to allow them to get nourishment. Despite all this, Douglas seemed quite upbeat about his chances: “I am head and neck,” Douglas said. “I am above the neck, so nothing’s gone down, and the expectations are good….” When pressed for odds, Douglas said it was about an” 80% chance” of recovery, and possibly higher at “certain hospitals”, and that he is doing all he can to beat this disease.
So, what does it mean that he has Stage 4 disease? What is cancer staging, and how is a patient’s tumor stage determined?
Staging describes the extent or severity of an individual’s cancer and is based on the extent of the original (primary) tumor and the extent of spread in the body. This is important because:
What is the basis for staging?
Staging is based on knowledge of the way cancer develops. Cancer cells divide and grow without control or order to form a mass of tissue, called a growth or tumor. As the tumor grows, it can invade nearby organs and tissues. Cancer cells can also break away from the tumor and enter the bloodstream or lymphatic system. By moving through the bloodstream or lymphatic system, cancer can spread from the primary site to form new tumors in other organs. The spread of cancer is called metastasis.
What are the common elements of staging systems?
Staging systems for cancer have evolved over time. They continue to change as scientists learn more about cancer. Some staging systems cover many types of cancer; others are specific to a particular type. The common elements considered in most staging systems are:
What is the TNM system?
The TNM system is one of the most commonly used staging systems. Most medical facilities use the TNM system as their main method for cancer reporting. It is based on the extent of the tumor (T), the extent of spread to the lymph nodes (N), and the presence of metastasis (M). A number is added to each letter to indicate the size or extent of the tumor and the extent of spread.
Tumors (T) and lymph nodes (L) designated as:
Metastasis (M) are designated as MX- can’t be evaluated, M0- cancer has not spread to other parts of the body and M1- cancer has spread to distant parts of the body.
As an example, breast cancer T3 N2 M0 refers to a large tumor that has spread outside the breast to nearby lymph nodes, but not to other parts of the body. Prostate cancer T2 N0 M0 means that the tumor is located only in the prostate and has not spread to the lymph nodes or any other part of the body.
For many cancers, TNM combinations correspond to one of five stages. Criteria for stages differ for different types of cancer. For example, bladder cancer T3 N0 M0 is stage III; however, colon cancer T3 N0 M0 is stage II.
|Stage 0||Carcinoma in situ (early cancer that is present only in the layer of cells in which it began).|
|Stage I, Stage II, and Stage III||Higher numbers indicate more extensive disease: greater tumor size, and/or spread of the cancer to nearby lymph nodes and/or organs adjacent to the primary tumor.|
|Stage IV||The cancer has spread to another organ.|
What types of tests are used to determine stage?
The types of tests used for staging depend on the type of cancer. Tests may include the following: