Key Points for This Section

After oropharyngeal cancer has been diagnosed, tests are done to find out if cancer cells have spread within the oropharynx or to other parts of the body. There are three ways that cancer spreads in the body. The following stages are used for oropharyngeal cancer: Stage 0 (Carcinoma in Situ) Stage I Stage II Stage III Stage IVA Stage IVB Stage IVC

After oropharyngeal cancer has been diagnosed, tests are done to find out if cancer cells have spread within the oropharynx or to other parts of the body.

The process used to find out if cancer has spread within the oropharynx or to other parts of the body is called staging. The information gathered from the staging process determines the stage of the disease. It is important to know the stage in order to plan treatment. The results of some of the tests ¹ used to diagnose oropharyngeal cancer are often used to stage the disease.

There are three ways that cancer spreads in the body.

The three ways that cancer spreads in the body are:

• Through tissue. Cancer invades the surrounding normal tissue.
• Through the lymph system. Cancer invades the lymph system and travels through the lymph vessels to other places in the body.
• Through the blood. Cancer invades the veins and capillaries and travels through the blood to other places in the body.

When cancer cells break away from the primary (original) tumor and travel through the lymph or blood to other places in the body, another (secondary) tumor may form. This process is called metastasis. The secondary (metastatic) tumor is the same type of cancer as the primary tumor. For example, if breast cancer spreads to the bones, the cancer cells in the bones are actually breast cancer cells. The disease is metastatic breast cancer, not bone cancer.

The following stages are used for oropharyngeal cancer:

Stage 0 (Carcinoma in Situ)

In stage 0, abnormal cells are found in the lining of the oropharynx. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma in situ.

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Pea, peanut, walnut, and lime show tumor sizes.

Stage I

In stage I, cancer has formed and is 2 centimeters or smaller and has not spread outside the oropharynx.

Stage II

In stage II, the cancer is larger than 2 centimeters, but not larger than 4 centimeters, and has not spread outside the oropharynx.

Stage III

In stage III, the cancer is either:

• larger than 4 centimeters and has not spread outside the oropharynx; or
• any size and has spread to only one lymph node on the same side of the neck as the cancer. The lymph node with cancer is 3 centimeters or smaller.

Stage IVA

In stage IVA, the cancer either:

• has spread to tissues near the oropharynx, including the voice box, roof of the mouth, lower jaw, muscle of the tongue, or central muscles of the jaw, and may have spread to one or more nearby lymph nodes, none larger than 6 centimeters; or
• is any size and has spread to one lymph node that is larger than 3 centimeters but not larger than 6 centimeters on the same side of the neck as the cancer, or to more than one lymph node, none larger than 6 centimeters, on one of both sides of the neck.

Stage IVB

In stage IVB, the cancer either:

• surrounds the main artery in the neck or has spread to bones in the jaw or skull, to muscle in the side of the jaw, or to the upper part of the throat behind the nose, and may have spread to nearby lymph nodes; or
• has spread to a lymph node that is larger than 6 centimeters and may have spread to tissues around the oropharynx.

Stage IVC

In stage IVC, cancer has spread to other parts of the body; the tumor may be any size and may have spread to lymph nodes.

Glossary Terms

Not normal. An abnormal lesion or growth may be cancer, premalignant (likely to become cancer), or benign (not cancer).

A blood vessel that carries blood from the heart to tissues and organs in the body.

A tissue with red blood cells, white blood cells, platelets, and other substances suspended in fluid called plasma. Blood takes oxygen and nutrients to the tissues, and carries away wastes.

Primary bone cancer is cancer that forms in cells of the bone. Some types of primary bone cancer are osteosarcoma, Ewing sarcoma, malignant fibrous histiocytoma, and chondrosarcoma. Secondary bone cancer is cancer that spreads to the bone from another part of the body (such as the prostate, breast, or lung).

Cancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare.

A term for diseases in which abnormal cells divide without control and can invade nearby tissues. Cancer cells can also spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord.

The smallest type of blood vessel. A capillary connects an arteriole (small artery) to a venule (small vein) to form a network of blood vessels in almost all parts of the body. The wall of a capillary is thin and leaky, and capillaries are involved in the exchange of fluids and gases between tissues and the blood.

A group of abnormal cells that remain in the place where they first formed. They have not spread. These abnormal cells may become cancer and spread into nearby normal tissue. Also called stage 0 disease.

The individual unit that makes up the tissues of the body. All living things are made up of one or more cells.

A measure of length in the metric system. There are 100 centimeters in a meter and 2½ centimeters in an inch.

The process of identifying a disease, such as cancer, from its signs and symptoms.

Cancer that has spread beyond the layer of tissue in which it developed and is growing into surrounding, healthy tissues. Also called infiltrating cancer.

The clear fluid that travels through the lymphatic system and carries cells that help fight infections and other diseases. Also called lymphatic fluid.

A rounded mass of lymphatic tissue that is surrounded by a capsule of connective tissue. Lymph nodes filter lymph (lymphatic fluid), and they store lymphocytes (white blood cells). They are located along lymphatic vessels. Also called lymph gland.

A thin tube that carries lymph (lymphatic fluid) and white blood cells through the lymphatic system. Also called lymphatic vessel.

The tissues and organs that produce, store, and carry white blood cells that fight infections and other diseases. This system includes the bone marrow, spleen, thymus, lymph nodes, and lymphatic vessels (a network of thin tubes that carry lymph and white blood cells). Lymphatic vessels branch, like blood vessels, into all the tissues of the body.

The spread of cancer from one part of the body to another. A tumor formed by cells that have spread is called a “metastatic tumor” or a “metastasis.” The metastatic tumor contains cells that are like those in the original (primary) tumor. The plural form of metastasis is metastases (meh-TAS-tuh-SEEZ).

Cancer that forms in tissues of the oropharynx (the part of the throat at the back of the mouth, including the soft palate, the base of the tongue, and the tonsils). Most oropharyngeal cancers are squamous cell carcinomas (cancer that begins in flat cells lining the oropharynx).

The part of the throat at the back of the mouth behind the oral cavity. It includes the back third of the tongue, the soft palate, the side and back walls of the throat, and the tonsils.

The original tumor.

The extent of a cancer in the body. Staging is usually based on the size of the tumor, whether lymph nodes contain cancer, and whether the cancer has spread from the original site to other parts of the body.

Cancer that is 2 centimeters or smaller and has not spread outside the oropharynx.

Cancer that is larger than 2 centimeters, but not larger than 4 centimeters, and has not spread outside the oropharynx.

Cancer that is either (1) larger than 4 centimeters and has not spread outside the oropharynx; or (2) any size and has spread to only one lymph node on the same side of the neck as the cancer, and the lymph node with cancer is 3 centimeters or smaller.

Stage IV oropharyngeal cancer is divided into stages IVA, IVB, and IVC. In stage IVA, the cancer either: (1) has spread to tissues near the oropharynx, including the voice box, roof of the mouth, lower jaw, muscle of the tongue, or central muscles of the jaw, and may have spread to one or more nearby lymph nodes, none larger than 6 centimeters; OR (2) is any size and has spread to one lymph node that is larger than 3 centimeters but not larger than 6 centimeters on the same side of the neck as the cancer, or to more than one lymph node, none larger than 6 centimeters, on one or both sides of the neck. In stage IVB, the cancer either: (1) surrounds the main artery in the neck or has spread to bones in the jaw or skull, to muscle in the side of the jaw, or to the upper part of the throat behind the nose, and may have spread to nearby lymph nodes; OR (2) has spread to a lymph node that is larger than 6 centimeters and may have spread to tissues around the oropharynx. In stage IVC, cancer has spread to other parts of the body; the tumor may be any size and may have spread to lymph nodes.

Performing exams and tests to learn the extent of the cancer within the body, especially whether the disease has spread from the original site to other parts of the body. It is important to know the stage of the disease in order to plan the best treatment.

The hollow tube inside the neck that starts behind the nose and ends at the top of the trachea (windpipe) and esophagus (the tube that goes to the stomach). The throat is about 5 inches long, depending on body size. Also called pharynx.

A group or layer of cells that work together to perform a specific function.

An abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Tumors may be benign (not cancer), or malignant (cancer). Also called neoplasm.

A blood vessel that carries blood to the heart from tissues and organs in the body.