Grading and Staging

Grading and Staging

Both primary and metastatic tumors of the spine are graded and staged. Tumors of the spinal cord however, are typically graded but not staged because they tend to remain in the spinal cord and don’t spread to other parts of the body. Knowing the grade and stage of a tumor helps your care team better tailor your treatment plan for better outcomes.

What is Staging?

Staging is the term oncologists use to define where cancer is located and how much it has spread. Once the stage of cancer is determined, your physician can recommend a particular course of treatment.

Most cancer teams use the system developed by the American Joint Committee on Cancer, known as the TNM staging system.

T = Tumor: Where is the primary tumor and how large is it?
N = Nodes: Has the tumor spread to nearby lymph nodes?
M = Metastasis: Has cancer spread to other parts of the body?

For each letter, there are five numbered stages, from 0 to 4, depending on how much the cancer has spread. The lower the number, the more the cancer cells look like normal cells and the easier they are to treat and cure. A higher number means it has spread more deeply.

The place where cancer originates is called the primary site. Cancer can spread from the primary site to other parts of the body. It’s important to understand that even if cancer is found in other parts of your body, it’s still considered the form of cancer where it first appeared. For instance, if colon cancer has spread to the liver, it’s called metastatic colon cancer, not liver cancer.

Be sure to talk to your physician about your particular stage of cancer and how that will impact your treatment.

What is Tumor Grading?

Northwestern Medicine oncologists use a grading system developed by the World Health Organization as one key factor to help them determine how to best treat spine tumors. A tumor's grade is determined by looking at cells from the tumor under a microscope.

Grade I: The least malignant and slowest growing, cells in a grade I tumor look like normal brain cells. Your physician may choose to remove a grade I tumor with surgery, if it can be done safely. Or your treatment may include medication and yearly MRI scans to monitor growth.

Grade II: This tumor has cells that appear less normal under a microscope and is considered malignant. A grade II tumor grows slowly, but has more of a chance to spread into nearby tissue or to recur. If removed, it may come back as a higher grade tumor.

Grade III: This tumor is malignant, grows quickly and is likely to spread into nearby tissue. When removed, it often comes back as a grade IV tumor.

Grade IV: This type of tumor is the most malignant, with cells that are very abnormal. It grows and spreads quickly into others areas of the brain. Surgery is unable to reach all of these areas without harming the brain, so other types of treatment are often needed.