Cancer Stages- Your Quick and Easy Guide

Ekta Nayee, PharmD

Published Apr 30, 2023

If you or your loved one has recently been diagnosed with cancer, you may have heard the doctor refer to cancer with letters and numbers. For example, “Breast Cancer Stage 2” or “T2 N1 M0.” What do these letters and numbers mean and why are they so important?

The Purpose of Cancer Stages

Cancer stages describe how large a cancerous site (tumor) is and how far it has spread in the body. Doctors collect lab tests, image studies, and biopsies to diagnose and stage cancer. Once the cancer is staged, the staging remains the same, even if the tumor gets bigger or smaller later on.

The healthcare team compares images of the cancer before and after treatment. Cancer staging helps them determine how aggressive the cancer is, how best to treat it, and how effective the treatment was. It also helps healthcare professionals discuss treatment plans with each other.

There are several types of staging systems used worldwide. The most common are the Number Staging System and the TNM Staging System.

TNM Staging System

TNM staging is the most suitable way to stage solid tumor cancers, such as breast, prostate, lung, and colon cancer. TNM staging consists of 3 parts:

T (Tumor Size): This describes the main tumor.

Ranges from T1 to T4, with the higher number representing a larger tumor
T0 means a primary tumor was not detected
TX means tumor size can’t be determined

N (Lymph Node Involvement): This describes cancer spread to nearby lymph nodes.

Ranges from N1 to N3, with the larger number indicating more lymph nodes affected
N0 means cancer hasn’t spread to lymph nodes
NX means nearby lymph node spread can’t be assessed

M (Metastatic Spread): This describes whether the cancer has spread through the blood or lymph nodes to other body parts (for example, from the breast to the liver).

M1 means the cancer has spread
M0 means the cancer has not spread

Number Staging System

This is also called the Overall Staging System. Stages consist of numbers (1 to 4) or Roman numerals (I to IV). A higher number correlates to a larger and more spread out cancer.

Stage 0: Refers to abnormal cell growth that may later become cancerous. This stage is also known as cancer-in-situ (CIS).
Stage 1 to 3 (I-III): Cells are cancerous. The larger the number, the bigger the tumor and the more the cancer has spread in nearby areas.
Stage 4 (IV): Metastatic stage. Cancer has spread to more distant tissues and lymph nodes.

The staging numbers may have additional letters and numbers after them, for example: Cancer Stage 2A, which further describe the cancer. The exact definitions of these additional letters and numbers are different for each type of cancer. To get a more detailed explanation of your specific cancer staging, please refer to the resources listed at the end of this article.

Exceptions to Cancer Staging

It’s important to note that cancer stages are not used for all cancers. For example, blood cancers, such as leukemia, aren’t staged because there’s no solid tumor.

Fighting Cancer a Day at a Time

Cancer staging remains the same from the point of diagnosis onward. The staging helps healthcare providers narrow down optimal cancer treatments and monitor their effectiveness.

Cancer staging is helpful to you too. Understanding the staging letters and numbers gives you a better picture of where and how big the cancer is. It also helps you get a general idea of ongoing cancer research developments. The key takeaway is that the more you know about your cancer, the better equipped you are in the fight against it.

Please visit the following resources for in-depth explanations of your specific cancer stage and much more:

#cancer #cancerstages

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References