Sarcoma

Staging

Staging describes the extent of your cancer, its location and whether it has spread. Knowing the stage helps your doctor recommend the most effective treatment plan.

When staging sarcoma, doctors evaluate the appearance of the tumor under the microscope to judge how fast it may be growing. This evaluation helps determine if the cancer is close to the surface of the skin (superficial) or deep in the body, and whether it has spread to your lymph nodes or to other parts of your body. Lymph nodes are bean-shaped cells found in small collections throughout the body. They store special cells that can trap cancer cells or bacteria traveling through the body via the lymphatic system.

A number of tests and procedures help determine the stage of your cancer. Your doctor may order a physical examination and history, biopsy of the tumor and lymph nodes, X-rays and blood tests. When examining the biopsy sample, the pathologist (a doctor who specializes in diagnosing diseases by looking at the tissue under a microscope) takes into account the number of cells that are actively dividing and how closely the cancer resembles normal tissue.

Your surgeon may elect to present your case at a multidisciplinary sarcoma tumor board. This is a meeting of a group of physicians, all members of the health care team that are involved with the treatment of sarcoma. It will include the surgeon, medical oncologist, radiation oncologist, pathologist, radiologist, tumor registrar, and other allied health personnel. This team will discuss and evaluate your case in great detail and arrive at decisions best suited to you personally.

Staging soft tissue sarcomas

The grade or stage of a sarcoma diagnosis is defined differently depending on which part of the body is involved.

Classification tables in this section represent the American Joint Committee on Cancer (AJCC) definitions of tumor, lymph node involvement and spread of disease (metastasis) that your doctor will use to determine your treatment plan. The tables also include grade and stage, as applicable.

Doctors typically use the AJCC TNM staging system to stage some soft tissue sarcomas, including all soft tissues of the head and neck, trunk and extremities, abdominal and thoracic visceral organs, and retroperitoneum.

The TNM system considers the size and location of the tumor (T), whether cancer cells are found in nearby lymph nodes (N) and whether the cancer has metastasized (M), or spread, to other parts of the body. The most common sites of spread are to the lungs or other bones.

An additional factor for classifying soft tissue sarcomas is the grade (G). Numbers after T, N, M and G provide more details about each of these factors. The grade of your cancer helps predict how rapidly it will grow and spread, as well as your prognosis.

The grading system divides soft tissue sarcomas into grades that are determined by examining sarcoma cells under a microscope. The factors include how different the cancer cells are from normal tissue, how many tumor cells are dividing and how much of the tumor has cells that are dying.

Grades are listed from low to high as GX (the grade cannot be assessed), grade 1 (G1), grade 2 (G2) and grade 3 (G3). Cells that appear healthy are called well-differentiated (denoted by a lower grade). Low-grade tumor cells look more like normal cells and are less likely to grow and spread quickly, whereas high-grade tumor cells (poorly differentiated cells) look more abnormal and tend to grow and spread faster. In general, the more differentiated the tumor, the better the prognosis.

To assign a stage, the information your doctor has gathered about the tumor, lymph nodes, metastasis and grade is combined in a process called stage grouping. The stage is described by Roman numerals from I to IV and the letters A or B. The stage is useful in the selection of treatment; however, other factors, such as where the sarcoma is located, also influence treatment planning and prognosis. Currently, stage groupings exist for soft tissue sarcomas of the trunk and extremities and the retroperitoneum. More data must be collected before stage groupings are defined for other soft tissue sarcomas.

Staging bone sarcomas

To stage bone sarcomas, doctors use many of the same imaging tests and similar physical examinations used in staging soft tissue sarcomas. After determining if the bone sarcoma is localized (seen only in the bone it started in and possibly the tissues next to the bone, such as muscle, tendon or fat) or metastatic (spread to other parts of the body), doctors typically use one of two preferred staging systems.

  • The AJCC TNM staging system is generally used to stage bone sarcomas. As noted earlier, this system considers the size and location of the tumor (T), whether cancer cells are found in nearby lymph nodes (N) and whether the cancer has metastasized (M), or spread, to other parts of the body. It also includes a grading system that is divided into three grades.
  • The Musculoskeletal Tumor Society (MSTS) staging system, also known as the Enneking system, is based on the grade (G) of the tumor, the extent of the main (primary) tumor (T) and whether the tumor has metastasized (M) or spread to nearby lymph nodes or other organs.

The grade of a tumor is a measure of how likely it is to grow and spread, based on how it looks under the microscope. Tumors are either low grade (G1) or high grade (G2). Low-grade tumor cells look more like normal cells and are less likely to grow and spread quickly, whereas high-grade tumor cells look more abnormal and tend to grow and spread faster.

In the MSTS system, the extent of the primary tumor is classified as either intracompartmental (T1), meaning it has basically remained within the bone, or extracompartmental (T2), meaning it has extended beyond the bone into other nearby structures.

Tumors that have not spread to the lymph nodes or other organs are considered M0, and those that have spread are considered M1.

These factors are combined to give an overall stage, represented by Roman numerals I, II and III. Stages I and II are further divided into A for intracompartmental tumors or B for extracompartmental tumors.

Soft Tissue Sarcoma of the Head & Neck

Classifying Head & Neck

Classification Definition
Tumor (T)
TX Primary tumor cannot be assessed
T1 Tumor is less than or equal to 2 cm
T2 Tumor is more than 2 cm to 4 cm
T3 Tumor is more than 4 cm
T4
T4a


T4b
Tumor with invasion of adjoining structures
Tumor with orbital invasion, skull base/dural invasion, invasion of central compartment viscera, involvement of facial skeleton or invasion of pterygoid muscles
Tumor with brain parenchymal invasion, carotid artery encasement, prevertebral muscle invasion, or central nervous system involvement via perineural spread
Nodes (N)
N0 No regional lymph node metastases or unknown lymph node status
N1 Regional lymph node metastasis
Metastasis (M)
M0 No distant metastasis
M1 Distant metastasis

Grade

Grade (G) Definition
GX Grade cannot be assessed
G1 Total differentiation, mitotic count and necrosis score of 2 or 3
G2 Total differentiation, mitotic count and necrosis score of 4 or 5
G3 Total differentiation, mitotic count and necrosis score of 6, 7 or 8

 

Soft Tissue Sarcoma of the Abdominal and Thoracic Visceral Organs

Classifying Abdominal and Thoracic Visceral Organs

Classification Definition
Tumor (T)
TX Primary tumor cannot be assessed
T1 Organ confined
T2
T2a
T2b
Tumor extension into tissue beyond organ
Invades serosa or visceral peritoneum
Extension beyond serosa (mesentery)
T3 Invades another organ
T4
T4a
T4b
T4c
Multifocal involvement
Multifocal (2 sites)
Multifocal (3-5 sites)
Multifocal (more than 5 sites)
Nodes (N)
N0 No regional lymph node metastasis or unknown lymph node status
N1 Lymph node involvement present
Metastasis (M)
M0 No metastasis
M1 Metastases present

Grade

Grade (G) Definition
GX Grade cannot be assessed
G1 Total differentiation, mitotic count and necrosis score of 2 or 3
G2 Total differentiation, mitotic count and necrosis score of 4 or 5
G3 Total differentiation, mitotic count and necrosis score of 6, 7 or 8

 

Soft Tissue Sarcoma of the Trunk & Extremities

Classifying Trunk & Extremities

Classification Definition
Tumor (T)
TX Primary tumor cannot be assessed
T0 No evidence of primary tumor
T1 Tumor is 5 cm (2 inches) or less in greatest dimension
T2 Tumor is more than 5 cm and less than or equal to 10 cm in greatest dimension
T3 Tumor is more than 10 cm and less than or equal to 15 cm in greatest dimension
T4 Tumor is more than 15 cm in greatest dimension
Nodes (N)
N0 No regional lymph node metastasis or unknown lymph node status
N1 Regional lymph node metastasis
Metastasis (M)
M0 No distant metastasis
M1 Distant metastasis

Grade

Grade (G) Definition
GX Grade cannot be assessed
G1 Total differentiation, mitotic count and necrosis score of 2 or 3
G2 Total differentiation, mitotic count and necrosis score of 4 or 5
G3 Total differentiation, mitotic count and necrosis score of 6, 7 or 8

Staging Trunk & Extremities

Stage T N M G
IA T1 N0 M0 G1, GX
IB T2, T3, T4 N0 M0 G1, GX
II T1 N0 M0 G2, G3
IIIA T3, T4 N0 M0 G2, G3
IIIB T1 N0 M0 G2, G3
IV
Any T
Any T
N1
Any N
M0
M1
Any G
Any G

 

Soft Tissue Sarcoma of the Retroperitoneum

Classifying Retroperitoneum

Classification Definition
Tumor (T)
TX Primary tumor cannot be assessed
T0 No evidence of primary tumor
T1 Tumor is 5 cm (2 inches) or less in greatest dimension
T2 Tumor is more than 5 cm and less than or equal to 10 cm in greatest dimension
T3 Tumor is more than 10 cm and less than or equal to 15 cm in greatest dimension
T4 Tumor is more than 15 cm in greatest dimension
Nodes (N)
N0 No regional lymph node metastasis or unknown lymph node status
N1 Regional lymph node metastasis
Metastasis (M)
M0 No distant metastasis
M1 Distant metastasis

Grade

Grade (G) Definition
GX Grade cannot be assessed
G1 Total differentiation, mitotic count and necrosis score of 2 or 3
G2 Total differentiation, mitotic count and necrosis score of 4 or 5
G3 Total differentiation, mitotic count and necrosis score of 6, 7 or 8

Staging Retroperitoneum

Stage T N M G
IA T1 N0 M0 G1, GX
IB T2, T3, T4 N0 M0 G1, GX
II T1 N0 M0 G2, G3
IIIA T2 N0 M0 G2, G3
IIIB
T3, T4
Any T
N0
N1
M0
M0
G2, G3
Any G
IV Any T Any N M1 Any G

Additional Resources

 

Previous Next

 



Register Now! Sign Up For Our Free E-Newletter!

Read Inspiring Cancer Survivor Stories

Order Your Guides Here