The process of finding out how far a cancer has spread is called staging. The extent of spread of nasopharyngeal cancer (NPC) is the most important factor in selecting treatment options and estimating your outlook for recovery from treatment and for survival. If you have NPC, ask your cancer care team to explain the staging in a way that you understand. By knowing all you can about staging, you can take a more active role in making informed decisions about your treatment.

A staging system is a way for members of the cancer care team to summarize the extent of a cancer's spread. The most common system used to describe the spread of NPC is the TNM system created by the American Joint Committee on Cancer (AJCC).

• T stands for tumor (its size and how far it has spread locally within the nasopharynx and to nearby tissues).

• N stands for spread to lymph nodes (small bean-shaped collections of immune system cells that help the body fight infections and cancers).

• M is for metastasis (spread to distant organs).

Additional letters or numbers appear after T, N, and M to provide more details about each of these factors. The numbers 0 through 4 indicate increasing severity. The letter X means "cannot be assessed because the information is not available." The letters "is" after the T stand for "in situ," which means the tumor is contained in one place and has not yet spread to a deeper layer of tissue. To assign a stage, information about the tumor, lymph nodes, and metastasis is combined according to a process called stage grouping (see later text).

T Stages for Nasopharyngeal Carcinoma

TX: Primary tumor cannot be assessed due to incomplete information

T0: No evidence of a primary tumor

Tis: Carcinoma in situ (cancer cells are present only in the surface layer of the nasopharynx but have not invaded into other layers)

T1: Tumor is limited to the nasopharynx

T2: Tumor has spread to tissues (but not bone) outside the nasopharynx

T3: Tumor has spread to the sinuses or the bones near the nasopharynx

T4: Tumor has spread into the skull and/or cranial nerves (nerves in the head that lie near the nasopharynx and have special functions such as vision, smell, and eye movement), the hypopharynx (lower part of the throat), the eye, or its nearby tissues

N Stages for Nasopharyngeal Carcinoma

NX: Regional lymph nodes cannot be assessed due to incomplete information

N0: No regional lymph node spread

N1: Spread to 1 or more single lymph nodes, not larger than 6 cm (about 2½ inches), in the same side of the neck as the original cancer

N2: Metastasis to lymph nodes, not larger than 6 cm, on both sides of the neck

N3: Metastasis to 1 or more lymph nodes that are larger than 6 cm or are located just above the collarbone.

M Stages for Nasopharyngeal Carcinoma

MX: Presence of distant metastasis cannot be assessed

M0: No distant metastasis

M1: Distant metastasis is present, involving other organs in the body

TNM Stage Grouping

To help guide treatment decisions, several of these T, N, and M combinations can be grouped together into a simpler set of stages, which are described by Roman numerals 0 to IV. Patients with lower stage cancer have a better prognosis for a cure or long-term survival. Here are the grouped stages and the TNM combinations that define them.

Stage 0: Tis, N0, M0: The cancer is "in situ." It has not yet penetrated to a deeper layer of nasopharyngeal tissue and has not spread to lymph nodes or distant sites.

Stage I: T1, N0, M0: The tumor is only in the nasopharynx and has not spread to lymph nodes or distant sites.

Stage IIA: T2a, N0, M0: The tumor has spread to soft tissues of the nasal cavity and/or the oropharynx but no farther and has not spread to lymph nodes or distant sites.

Stage IIB: T2b, N0 or N1, M0, T1or 2 or 2a, N1, M0: The tumor has spread to soft tissues of the nasal cavity and the oropharynx, but not into bone. It has spread to one or more single lymph nodes, not larger than 6 cm (about 2½ inches), in the same side of the neck as the original cancer. The cancer has not spread to distant sites.

Stage III: T1or 2, N2, M0, T3, N0-2, M0: The tumor has spread to soft tissues of the nasal cavity and/or the oropharynx and to lymph nodes, not larger than 6 cm, on both sides of the neck but not to distant sites. Or the tumor has spread to the sinuses or the bones near the nasopharynx and may or may not have spread to lymph nodes but not to distant sites

Stage IVA: T4, N0-2, M0: The tumor has spread to the skull and/or cranial nerves (nerves in the head that lie near the nasopharynx and have special functions such as vision, smell, eye movement), the hypopharynx (lower part of the throat), the eye, or its nearby tissues and may or may not have spread to lymph nodes smaller than 6 cm but not to distant sites.

Stage IVB: Any T, N3, M0: The tumor is of any size but has spread to one or more lymph nodes that are larger than 6 cm and/or located above the collarbone area but not to distant sites.

Stage IVC: Any T, any N, M1: The tumor is of any size and may or may not have spread to lymph nodes but has spread to distant sites.

Recurrent: Cancer that has come back (recurred) after treatment has taken place is called recurrent disease. Recurrent NPC may return in the nasopharynx, neck, or another part of the body, often the lung.

Survival by stage: Listed below is the 5-year relative survival for each of the 4 main stages. Keep in mind that 5-year survival rates are based on patients diagnosed and initially treated more than 5 years ago. Improvements in treatment often result in a more favorable outlook for recently diagnosed patients.

Stage	5-year survival
I	63%
II	52%
III	56%
IV	39%

The 5-year survival rate refers to the percentage of patients who live at least 5 years after their cancer is diagnosed. Five-year rates are used to produce a standard way of discussing prognosis. Of course, many people live much longer than 5 years. Five-year relative survival rates assume that people will die of other causes and compares the observed survival with that expected for people without nasopharyngeal cancer. That means that relative survival only talks about deaths from nasopharyngeal cancer.

Because nasopharyngeal cancers are so uncommon, these figures are based on small numbers from the United States (AJCC Staging Manual, 6th edition) and are not totally consistent. This explains why stage III has a better survival than stage II.

A larger, study of more recently treated patients (radiation only) was published by Dr. T Leung and others from Hong Kong. These showed the following overall cancer specific survival (only people who died of the cancer):

Stage	5-year survival
I	91%
IIA	95%
IIB	82%
III	67%
IV	46-50%

Modern results may be better with the use of chemotherapy (see below). Last Revised: 08/03/2006