© 2005-2012 American Society of Clinical Oncology (ASCO). All rights reserved worldwide.
Staging is a way of describing where a tumor is located, whether it is cancerous, if or where it has spread, and whether it is affecting the functions of other organs in the body. Doctors use diagnostic tests to determine the tumor's stage, so staging may not be complete until all the 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 tumors.
The staging below describes lacrimal gland carcinomas. For more information on the staging of ocular non-Hodgkin lymphoma, see the Guide to Non-Hodgkin Lymphoma.
One tool that doctors use to describe the stage of a lacrimal gland tumor is the TNM system. This system judges three factors: the tumor itself, the lymph nodes around the tumor, and if the tumor has spread to the rest of the body. The results are combined to determine the stage 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 disease so doctors can work together to plan the best treatments. Not all doctors may use this staging system for lacrimal gland tumor; talk with your doctor for more information about staging.
TNM is an abbreviation for tumor (T), node (N), and metastasis (M). Doctors look at these three factors to determine the stage:
- 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 size and location of the tumor. Some stages are also divided into smaller groups that help describe the tumor in even more detail. Specific tumor stage information is listed below:
TX: The primary tumor cannot be evaluated.
T0 (T plus zero): There is no tumor.
T1: The tumor is 2 centimeters (cm) or smaller and may or may not extend outside of the lacrimal gland to the orbital soft tissue.
T2: The tumor is between 2 cm and 4 cm and likely extends to the orbital soft tissue.
T3: The tumor is greater than 4 cm and likely extends to the orbital soft tissue.
T4: The tumor has invaded the periosteum (the membrane of connective tissue that covers the bone) or the orbital bone.
T4a: The tumor has invaded the periosteum.
T4b: The tumor has invaded the orbital bone.
T4c: The tumor has extended beyond the orbit to adjacent structures, including the brain and sinuses.
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 lacrimal gland 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 lacrimal glands 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.
Histologic grade. In addition to the TNM system, the doctor may describe a tumor by its grade. Histologic grade describes how closely the tumor 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: The cells are somewhat different (moderately differentiated).
G3: The tumor cells look very much alike (poorly differentiated).
G4: The cells barely resemble normal cells (undifferentiated).
Recurrent: Recurrent cancer is cancer that comes back after treatment. If there is a recurrence, the cancer may need to be staged again (called re-staging) using the system above.
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, Seventh Edition (2010) published by Springer-Verlag New York, www.cancerstaging.net.