The Ericksons

Staging Systems for Cancer

Doctors stage a patient’s cancer at the time of diagnosis. Doctors determine the extent of your cancer, such as how large the tumor is, and if it has spread, using x-rays, lab tests, and other tests or procedures .  This is called the “stage” of your cancer. By staging the cancer, your doctor can determine among other things, how aggressive the cancer is and how aggressive the treatment will have to be.

Most staging systems include information about (1):Staging Systems

  • Where the tumor is located in the body
  • The cell type (such as adenocarcinoma or squamous cell carcinoma)
  • The size of the tumor
  • Whether cancer has spread to nearby lymph nodes
  • Whether cancer has spread to a different part of the body
  • Tumor grade, which refers to how abnormal the cancer cells look and how likely the tumor is to grow and spread

The most commonly used system of staging is the TNM System.

The most common place to see this is on a pathology report.

What is the TNM System?

T stands for tumor.

Numbers (and sometimes the letter X) accompany the T.

X means the main tumor can’t be measured. O means that it can’t be found. Numbers 1-4 indicate the size and extent of the primary tumor. The higher the number, the larger the tumor, and the more it is invading nearby tissue. These numbers are sometimes broken down further, to give a more precise picture of how extensive the cancer is. For example, T2a and T2b. A would be closer to T2 and b would be closer to T3.

N stands for regional lymph nodes.

The number (or the letter X) accompanying the N indicates the number of nearby nodes that are cancerous.

X means that cancer in nearby nodes can’t be measured. 0 means there is no cancer in the nearby lymph nodes. Numbers 1-3 indicate the number of cancerous lymph nodes, and where they are. The higher the number, the more lymph nodes there are that contain cancer. Localized cancer is limited to the location where it started, with no indication that it has spread. Regional cancer has spread to nearby lymph nodes, tissues, or organs.

M stands for metastasis.

There are three possible letters/numbers that can accompany the M. X indicates that metastasis can’t be measured. 0 means that cancer hasn’t spread to other parts of the body. 1 means that it has spread to other parts of the body. When cancer is described as distant, it has spread to distant parts of the body.

From this TNM staging system, doctors derive the more commonly known, stages I to IV.

  • Stage 0 means that abnormal cells are present but haven’t spread. Doctors call this, “in situ,” or CIS. CIS isn’t cancer but could become cancer.
  • Stage I, II, and III mean that cancer is present. The higher the number, the greater the concern. Doctors asess the size of the cancer and how invasively it has spread into nearby tissue.
  • Stage IV is cancer that has spread to distant parts of the body.

The doctor said Dan’s cancer was at least stage IIIb. This was based on his tumor and lymph nodes. But was he stage IV? To find that out, doctors ordered a PET scan. It showed that cancer had crossed his thoracic region and was, therefore, distant. That made it stage IV.


Doctors stage lymphoma using a different system. They look at which lymph node regions are affected, and how many are affected. Again, as the number of the stage increases so does the extent of the cancer’s effect on the patient. Progressive or refractory lymphoma is when cancer continues to grow or spread despite treatment. When doctors treat lymphoma successfully and then it returns, they call it recurrent or relapsed lymphoma. (2)


Leukemia uses a completely different staging system known as the Rai staging system. The Rai system takes several things into consideration, including whether there are high levels of lymphocytes in the blood, also known as lymphocytosis. Does the patient have enlarged lymph nodes or lymphadenopathy? Is the patient’s spleen enlarged? This is called splenomegaly. Does the patient have anemia or low red blood cell counts? Are the patient’s platelets low, also known as thrombocytopenia? Is the patient’s liver enlarged? This is called hepatomegaly.

All stages of the Rai symptom include lymphocytosis (high levels of lymphocytes).

  • Stage 0 means that there is lymphocytosis, but no other staging conditions present.
  • Stage I is when lymphadenopathy accompanies lymphocytosis.
  • Stage II adds an enlarged spleen and/or liver, and possibly lymphadenopathy, as well.
  • Stage III includes anemia, and possibly lymphadenopathy and/or enlarged spleen and/or liver.
  • Stage IV includes thrombocytopenia (low levels of platelets) and possibly the other symptoms.

To make things even more complicated, European doctors use a completely different system known as Binet classification. Since I am writing in the United States, I won’t go into that system. (3)

Brain and Spinal Cord Tumors

Cancers of the brain and spinal cord tumors do not have a formal staging system. That’s because these kinds of tumors rarely spread to other parts of the body. This risk with these cancers is their effect on the brain and central nervous system. (4)

The Stage Stays the Same

The stage doesn’t change, even though the cancer might. Doctors refer to cancer by the stage it was given at diagnosis. It doesn’t matter if your cancer has improved due to successful treatment, or if it gets worse and spreads. If it was stage III, in the beginning, it’s still stage III after it has metastasized. Doctors add new information to the original stage over time as the cancer changes.


  1. National Cancer Institute, Diagnosis, and Staging. Staging.
  2. Cancer.Net Non-Hodgkin‘s Lymphoma Stages
  3. Cancer.Net Leukemia Stages
  4. Baylor Scott and White Health, The Stages of Brain and Spinal Cord Cancer


I am an author, writer, and speaker and homeschooling mom of 3. Since my husband, Dan was diagnosed with stage IV lung cancer in 2012, I’ve focused my writing and speaking on helping cancer patients and their families advocate for themselves and live life to the fullest, despite their illness.

My goal is to help people face cancer with grace.

My book Facing Cancer as a Friend: How to Support Someone Who Has Cancer, is available on

The Erickson Family, August 2016. Photo By Jim Bovin


Have any questions or comments? I would love to hear from you! By commenting, you agree to the terms of my privacy policy.

4 comments on “Staging Systems for Cancer

What a wonderful mission for your blog! I pray that your husband is doing well. He is blessed to have you (and I’m sure you feel the same about him). Cancer is scary and I feel it’s not an “if you get cancer…”, it’s “when”. Your information is very helpful! Found you through the A to Z Challenge.

Thank you so much, Diane. I appreciate your prayers and kind thoughts. Bless you!

What a wealth of information – you do a good job of breaking down a difficult and often overwhelming concept into something understandable.

Thank you, Nancy. Sometimes it feels like getting thrown into the deep end of the pool trying to absorb the information when a loved one is first diagnosed. I’m glad to be able to simplify some of it. Bless you!

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