Why It Is Important to Understand the Different Stages of Cancer

Joseph R. Anticaglia MD
Medical Advisory Board

Cancer is the second leading cause of death in the United States. The American Cancer Society estimated that in 2020 there will be 1.8 million new cancer cases diagnosed and 606,520 cancer deaths in the United States. Cancer staging and grading of these tumors are important guidelines for doctors and patients in dealing with the treatment and outcomes of this disease.

Jack is a 54 year old construction worker complaining of hoarseness and occasional coughing over the past three months. He smokes a pack of cigarettes a day for the past forty years and he says, “I’m in good health except for this hoarseness.”

He made an appointment to see a throat specialist who used an endoscope to visualize the voice box (larynx). It’s a long, thin, flexible tube with a light at the end of it. It is passed through the nose to examine the larynx.

Once the endoscopic examination was completed, the doctor turned to Jack and said, “I suspect there’s a tumor involving the right vocal fold of the larynx. It looks like an early-stage cancer, but we need to do a few things. We need to get some blood work and X-ray like images of the chest, larynx and neck.”

“After the test results, I recommend that you be admitted to the hospital so that I can perform a biopsy of the growth to get a definitive diagnosis.” The biopsy was performed and tested positive for squamous cell carcinoma. Jack’s tumor was classified as a T1N0M0 (see TNM system below).

Helen is a 43 year old woman who saw her doctor because of a lump in the breast. She noticed swollen lymph nodes in the area of the left armpit. Image studies (X-rays) of the chest were highly suggestive that the cancer had spread to the lung. The breast biopsy tested positive for cancer. She was classified as a T4N1M1.

Both Jack and Helen were diagnosed with cancer. but what do these different numbers and letters mean for their diagnosis, treatment, and their five-year survival outlook? Jack’s prognosis is excellent for a cure of his cancer whereas Helen’s cancer makes it a challenge for her to be alive five years after her cancer diagnosis. What do these different numbers and letters tell us about their diagnosis, treatment, and their five-year survival outlook?

TNM System

The TNM system is a valuable tool used to determine how to stage — categorize — your cancer. The letters TNM stand for tumor, node and metastasis. Your doctor will evaluate TNM and give each of these factors a number and a letter. The TNM system describes solid tumors such as breast, colon, lung, and laryngeal tumors. There may be a slight variation in the TNM symbols for each cancer.

T refers to the tumor’s size and how far it may have spread from their primary (origina)l location.

N refers to the lymph nodes. It describes whether the cancer has or has not spread to the lymph nodes. N0 (zero) indicates that the cancer has not spread to the lymph nodes. N1 indicates that the cancer has spread to the lymph nodes. Cancers with NO have a better prognosis.

M refers to the presence or absence of metastases — the development of secondary cancerous growths away from the original, primary location of the cancer. M0 (zero) indicates the absence of metastatic disease.

M1 tells us that metastatic disease is present. The breast cancer in Helen’s case, for instance, had spread to the lymph nodes and to an area beyond the breast, namely, the lung.

Grading of Cancers

Another component in the management of cancer patients involves the grading of cancers which describe the appearance of cancer cells. It refers to how cancer cells look to a pathologist while examining the cells under a microscope. They can be classified into low or high-grade cancers.

Low grade cancers have abnormal cells that look a lot like normal cells under the microscope.

These cells and tumors grow slowly and are well differentiated cancers.

High grade cancers do not resemble what a normal cell looks like. These abnormal looking cells tend to grow rapidly and are more likely to spread to lymph nodes and different areas of the body. High grade cancers are poorly differentiated cancers.

Wikimedia Commons
Cancer of the bladder

Many factors and a team of doctors contribute to staging cancer that include:

  • Medical history and physical examination
  • Imaging studies: X-rays, Computed Tomography (CT), Magnetic Resonance Imaging (MRI)
  • Laboratory tests: urinalysis, blood and fluid tests
  • Surgical reports
  • Pathology reports (High or Low grade cancer)
  • TNM system

The stage of cancer is a key component in the diagnosis, treatment, and survival of cancer patients. It can tell the clinician its location, whether the cancer has grown, and to what extent it may have spread (metastasized) to other organs. Cancer patients want to know how much cancer is in their bodies and whether it is localized or has spread to other parts of the body and what their future looks like.

Currently, numbers from I to IV (one to four) are assigned to cancers with number one describing a localized cancer with a favorable prognosis and four being a metastatic cancer that has spread beyond its primary site to other organs and tissues with a less favorable prognosis.

The Different Stages of Cancer

Most cancers are staged (grouped) into four categories numbered one to four. However,

Stage 0 (Carcinoma in-situ) are a group of abnormal cells that some refer to as being precancerous while others call them cancer cells. These cells remain in the place where it started (in situ-in place). It doesn’t spread to nearby tissues, not to lymph nodes nor does it metastasize to other organs.

  • T1: It’s often called early stage cancer (Primary Tumor-T). T1 cancers are small tumors that do hot spread to neighboring tissues, do not have lymph node involvement and don’t metastasize to other organs. It is localized to one area.
  • T2 & T3 are larger cancers that have spread into neighboring tissues. They can also spread to lymph nodes but they do not spread — metastasize to other parts of the body, such as the lungs.
  • T4 are often referred to as advanced tumors. T4 cancers are large tumors that spread to neighboring tissues, have lymph node involvement, and metastasize-spread to other parts of the body.

If you are diagnosed with cancer, your physician will tell you the size of the cancer, its location and whether it has spread to other parts of the body. Cancer staging is a valuable weapon that determines your treatment and the likelihood of you beating this disease. Medical discoveries are happening at a rapid pace, and your clinical stage may make you eligible for clinical trials and potential cures. It is important to understand the stage of your cancer and your options.


Jack’s cancer (T1NoMo) would be a stage 1 cancer with (no nodes and no metastases) and a plus a very favorable cure rate. Helen’s cancer (T4N1M1) would be categorized as a stage 4 cancer (with nodes and metastases present) making it a challenge to cure this cancer and difficult to prevent recurrences of her disease.


  1. American Joint Committee on Cancer; Cancer Staging System, Eighth edition, 2019
  2. Kenneth D. Kochanek, M. A., et al; Deaths: Final Data for 2017; CDC, National Vital Statistics Reports, June 24, 2019

This article is intended solely as a learning experience. Please consult your physician for diagnostic and treatment options.