Staging and Grading

Staging is a way of describing a cancer, such as where it is located, if or where it has spread, and if it is affecting the functions of other organs in the body. Doctors use diagnostic tests to determine the cancer’s stage, so staging may not be complete until all tests are finished. Knowing the stage helps the doctor to decide what kind of treatment is best and can help predict a patient’s prognosis (chance of recovery). There are different stage descriptions for different types of cancer.

For more information on the staging of melanoma, see the Cancer.Net Guide to Melanoma.

One tool that doctors use to describe the stage is the TNM system. This system uses three criteria to judge the stage of the cancer: the tumor itself, the lymph nodes around the tumor, and if the tumor has spread to other parts of the body. The results are combined to determine the stage of cancer for each person. There are five stages: stage 0 (zero) and stages I through IV (one through four). The stage provides a common way of describing the cancer so doctors can work together to plan the best treatments.

TNM is an abbreviation for tumor (T), node (N), and metastasis (M). Doctors look at these three factors to determine the stage of cancer:

• How large is the primary tumor and where is it located? (Tumor, T)
  
  
• Has the tumor spread to the lymph nodes? (Node, N)
  
  
• Has the cancer metastasized to other parts of the body? (Metastasis, M)

Tumor. Using the TNM system, the "T" plus a letter and/or number (0 to 4) is used to describe the stage of eyelid cancer. Some stages are also divided into smaller groups that help describe the tumor in even more detail. This helps the doctor develop the best treatment plan for each patient. Specific tumor stage information is listed below.

TX: The primary tumor cannot be evaluated.

T0 (T plus zero): There is no tumor.

Tis: Refers to carcinoma in situ. This means that the tumor remains in a very early, pre-invasive state, and its spread, if any, is very limited.

T1: The tumor is 5 millimeters (mm) or smaller in diameter, or is not invading the tarsal plate (the supporting structure of the eyelid).

T2: The tumor is larger than 5 mm, but not more than 10 mm in greatest diameter, or has invaded the tarsal plate.

T3: The tumor is larger than 10mm in greatest diameter, or has spread into the full thickness of the eyelid.

T4: The tumor has invaded adjacent structures, such as the bulbar conjunctiva, sclera and globe, soft tissues of the orbit, perineural space, bone and periosteum of the orbit, nasal cavity and paranasal sinuses, or central nervous system.

Node. The “N” in the TNM staging system stands for lymph nodes, the tiny, bean-shaped organs that help fight infection. Lymph nodes near the eyelid are called regional lymph nodes. Lymph nodes in other parts of the body are called distant lymph nodes.

NX: The regional lymph nodes cannot be evaluated.

N0 (N plus zero): There is no regional lymph node metastasis.

N1: There is regional lymph node metastasis.

Distant metastasis. The “M” in the TNM system indicates whether the cancer has spread from the eyelid to other parts of the body.

MX: Distant metastasis cannot be evaluated.

M0 (M plus zero): There is no distant metastasis.

M1: There is metastasis to other parts of the body.

Histopathology and grading

Histology describes how closely the cancer cells resemble normal tissue under a microscope. A tumor's grade is described using the letter G and a number.

GX: The tumor grade cannot be identified.

G1: Describes cells that look more like normal tissue cells (well differentiated).

G2: Describes cells that look somewhat different from normal cells (moderately differentiated).

G3: Describes tumor cells that look very much unlike normal cells (poorly differentiated).

G4: The tumor cells barely resemble normal cells (undifferentiated).

Recurrent: Recurrent cancer is cancer that comes back after treatment.

Used with permission of the American Joint Committee on Cancer (AJCC), Chicago, Illinois. The original source for this material is the AJCC Cancer Staging Manual, Sixth Edition (2002) published by Springer-Verlag New York, www.springer-ny.com.