UPDATE: More details on Michael Douglas’ diagnosis

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:

• It helps the doctor plan a person’s treatment.
• It can be used to estimate the person’s prognosis (likely outcome or course of the disease).
• It can help identify clinical trials (research studies) that may be suitable for a particular patient. Staging helps researchers and health care providers exchange information about patients. It also gives them a common language for evaluating the results of clinical trials and comparing the results of different trials.

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:

• Location of the primary tumor
• Tumor size and number of tumors
• Lymph node involvement (spread of cancer into lymph nodes)
• Cell type and tumor grade (how closely the cancer cells resemble normal tissue)
• Presence or absence of metastasis.

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:

• X – Tumor or lymph nodes can’t be evaluated
• 0- no evidence of tumor or lymph nodes
• 1,2,3,4- Size and extent of the primary tumor or number and/or extent of spread of regional lymph nodes

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.

Stages of Throat Cancer

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:

• Physical exams
• Imaging such as x-rays, computed tomography (CT) scans, magnetic resonance imaging (MRI) scans, and positron emission tomography (PET) scans can show the location of the cancer, the size of the tumor, and whether the cancer has spread.
• Laboratory tests are studies of blood, urine, other fluids, and tissues taken from the body. For example, tests for liver function and tumor markers (substances sometimes found in increased amounts if cancer is present) can provide information about the cancer.
• Pathology reports may include information about the size of the tumor, the growth of the tumor into other tissues and organs, the type of cancer cells, and the grade of the tumor (how closely, or not, the cancer cells resemble normal tissue).
• Surgical reports tell what is found during surgery. These reports describe the size and appearance of the tumor and often include observations about lymph nodes and nearby organs.

Source: National Cancer Institute