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

The process used to find out whether cancer has spread within the nasopharynx 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 the tests used to diagnose nasopharyngeal cancer are often also used to stage the disease. (See the General Information section.)

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 nasopharyngeal cancer:

Stage 0 (Carcinoma in Situ)

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

Stage I

In stage I, cancer has formed and the cancer:

• is found in the nasopharynx only; or
• has spread from the nasopharynx to the oropharynx and/or to the nasal cavity.

The oropharynx is the middle part of the throat and includes the soft palate, the base of the tongue, and the tonsils.

Enlarge

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

Stage II

In stage II nasopharyngeal cancer, the cancer:

• is found in the nasopharynx only or has spread from the nasopharynx to the oropharynx and/or to the nasal cavity. Cancer has spread to one or more lymph nodes on one side of the neck and/or to lymph nodes behind the pharynx. The affected lymph nodes are 6 centimeters or smaller; or
• is found in the parapharyngeal space. Cancer may have spread to one or more lymph nodes on one side of the neck and/or to lymph nodes behind the pharynx. The affected lymph nodes are 6 centimeters or smaller.

The oropharynx is the middle part of the throat and includes the soft palate, the base of the tongue, and the tonsils. The parapharyngeal space is a fat-filled, triangular area near the pharynx, between the base of the skull and the lower jaw.

Stage III

In stage III nasopharyngeal cancer, the cancer:

• is found in the nasopharynx only or has spread from the nasopharynx to the oropharynx and/or to the nasal cavity. Cancer has spread to one or more lymph nodes on both sides of the neck. The affected lymph nodes are 6 centimeters or smaller; or
• is found in the parapharyngeal space. Cancer has spread to one or more lymph nodes on both sides of the neck. The affected lymph nodes are 6 centimeters or smaller; or
• has spread to nearby bones or sinuses. Cancer may have spread to one or more lymph nodes on one or both sides of the neck and/or to lymph nodes behind the pharynx. The affected lymph nodes are 6 centimeters or smaller.

The oropharynx is the middle part of the throat and includes the soft palate, the base of the tongue, and the tonsils. The parapharyngeal space is a fat-filled, triangular area near the pharynx, between the base of the skull and the lower jaw.

Stage IV

Stage IV nasopharyngeal cancer is divided into stages IVA, IVB, and IVC.

• Stage IVA: Cancer has spread beyond the nasopharynx and may have spread to the cranial nerves, the hypopharynx (bottom part of the throat), areas in and around the side of the skull or jawbone, and/or the bone around the eye. Cancer may also have spread to one or more lymph nodes on one or both sides of the neck and/or to lymph nodes behind the pharynx. The affected lymph nodes are 6 centimeters or smaller.
• Stage IVB: Cancer has spread to lymph nodes between the collarbone and the top of the shoulder and/or the affected lymph nodes are larger than 6 centimeters.
• Stage IVC: Cancer has spread beyond nearby lymph nodes to other parts of the body.