Squamous Cell Carcinoma Stages

Squamous cell carcinoma, also known as squamous cell cancer, is the second most common type of skin cancer following basal cell carcinoma. About 1 million cases are diagnosed each year in the United States.

It begins in the squamous skin cells located in the top layer of skin called the epidermis. Squamous cell carcinoma is considered a slow-growing cancer, and staging is not always necessary since the disease is often diagnosed before it has spread. 

Basal cell carcinoma, which is a more common type of skin cancer, rarely spreads and is often not staged because the tumor is removed before staging is necessary. While squamous cell carcinoma is also a slow-growing cancer, its risk of spread is slightly higher than that of basal cell carcinoma. This article will explain how squamous cell carcinoma is staged and what other factors affect prognosis. 

Dermatologist examining mole of female patient with magnifying glass

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How the Stage Is Determined

Once you have been diagnosed with squamous cell carcinoma, your doctor will want to determine its stage. While the risk of this type of cancer spreading is low, determining the stage will help your doctor develop the best treatment plan. 

The TNM system is a uniform system for staging many types of cancer. TNM stands for:

  • T is for tumor: How far has the primary tumor grown through the layers of skin or to nearby tissues?
  • N is for nodes: Have cancer cells spread to the lymph nodes near the tumor?
  • M is for metastasis: Has the cancer metastasized (spread) to distant sites in the body such as the lungs or liver?

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What Are the 5 Stages of Skin Cancer?

Staging is an important tool used to treat skin cancer. Your stage helps the medical team determine where the tumor is, how large it is, where it has spread, your prognosis, and the most effective treatment plan. 

The five stages of squamous cell carcinoma include:

  • Stage 0: Also known as carcinoma in situ, in this stage cancer is present in the epidermis. It has not spread to deeper layers.
  • Stage 1: The tumor is smaller than 2 centimeters and has not spread to nearby lymph nodes or other organs. The individual has one or fewer risk factors for spread.
  • Stage 2: The tumor is wider than 2 centimeters and has not spread to nearby lymph nodes or other organs. This stage also applies to any sized tumor when the individual has two or more risk factors. 
  • Stage 3: The tumor has spread into nearby facial bones or one lymph node. It has not spread to other organs.
  • Stage 4: The tumor is of any size and has metastasized to one or more of the lymph nodes. It may have spread to the bones and other distant organs. 

How to Tell If Squamous Cell Carcinoma Has Spread

While it’s not common for squamous cell carcinoma to spread, it is helpful to be mindful of the signs. First, there are certain known risk factors to be aware of, as these characteristics have been associated with a higher stage of squamous cell carcinoma. Risk factors for squamous cell spreading include:

  • The tumor is thicker than 2 millimeters.
  • The tumor has grown into the lower dermis or subcutis layers of the skin.
  • The tumor has grown into the nerves in the skin.
  • The tumor is present on the ear or on a hair-bearing lip.

Knowing the stage of your cancer will help your medical team understand how serious it is and how best to treat it. Staging squamous cell carcinoma is based on a physical exam, detailed history, skin biopsy, lymph node biopsy, and imaging studies. 

To determine if your cancer has spread, your physician may recommend several diagnostic tests. A skin or lymph node biopsy (removing a sample of tissue to view in a lab) can show how far cancer cells have spread in the region of the primary tumor. Your medical team may also recommend a computed tomography (CT) scan to determine the spread. 

You may also be able to recognize squamous cell carcinoma spreading by its appearance. Possible symptoms of squamous cell carcinoma include:

  • A thick, red, scaly patch of skin
  • An open sore or scar
  • An elevated growth that is usually pink, red, or the color of your flesh. 
  • A wartlike nodule with raised edges

While most squamous cell carcinoma lesions are painless, it is possible to experience pain or numbness at the site.

What Are the Risk Factors for Squamous Cell Carcinoma?

Risk factors for squamous cell carcinoma include:

  • Unprotected exposure to ultraviolet (UV) rays
  • Light-colored hair, skin, or eyes 
  • History of skin cancer 
  • Age over 50
  • Male gender
  • Compromised immune system
  • History of human papillomavirus (HPV)
  • History of chronic skin infections

Factors Other than Stage that Affect Treatment Options and Prognosis

Fortunately, when caught early, squamous cell carcinoma can be treated and cured. In addition to the stage of your cancer, the medical team will look at the whole picture to determine the best treatment plan for you. 

Other factors to consider include:

  • The location of the tumor
  • The presence of pain, itching, or any other symptoms
  • The speed at which the cancer is growing
  • The tumor’s borders
  • A weakened immune system
  • Radiation therapy 
  • The pathologist’s report
  • Recurrence after treatment

Treatment for squamous cell carcinoma usually involves surgery to remove the lesion. The surgical options include:

  • Excision: The physician cuts out the tumor with a scalpel, along with a small margin of healthy skin around the tumor. 
  • Curettage and electrodesiccation: Used in small lesions, the physician scrapes away cancer cells, then cauterizes the skin to prevent bleeding.
  • Mohs surgery: The surgeon removes layers of skin and examines them under a microscope to determine if cancer is present. This process continues until no cancer cells are visible. 

Rarely, squamous cell carcinoma is treated with chemotherapy (cancer-killing drugs), radiation therapy (high doses of radiation to kill cancer cells), and immunotherapy (substances that stimulate your body’s immune response) when it has metastasized to other areas of the body. 

Summary

Squamous cell carcinoma is a slow-growing skin cancer that is often diagnosed before it has spread. Once you have been diagnosed, your physician will likely determine the stage before making a treatment recommendation. When caught early, squamous cell carcinoma is curable. 

A Word From Verywell

Learning that you have skin cancer is a frightening experience. It’s helpful to remember that squamous cell carcinoma is curable when caught early. If you have noticed a new sore or growth on your skin, see your dermatologist to get it checked out. 

Frequently Asked Questions

  • How long can you live with squamous cell carcinoma?

    When caught early, squamous cell carcinoma is curable. To determine your prognosis, your medical team will consider your cancer stage, where it is located, how quickly it is growing, and your overall health. 

  • Is squamous cell carcinoma a fast-growing cancer?

    No, squamous cell carcinoma is not considered a fast-growing cancer. While it tends to spread more quickly than basal cell carcinoma, squamous cell carcinoma is still considered a slow-growing type of skin cancer. 

  • Is stage 3 squamous cell carcinoma curable?

    Squamous cell carcinoma is considered curable when caught early. Stage 3 skin cancer has spread to nearby tissues and lymph nodes and, thus, is more difficult to treat. This type of cancer is treatable with surgery and other treatment options, like chemotherapy and radiation therapy. 

  • Do you need chemo for squamous cell carcinoma?

    Most cases of squamous cell carcinoma are treated with surgery to remove the cancerous growth. Rarely, when squamous cell carcinoma has already spread to other tissues, it may be treated with chemotherapy. Late-stage squamous cell carcinoma may also require radiation therapy and immunotherapy.

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7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Skin Cancer Foundation. Squamous Cell Carcinoma Warning Signs. Updated January 2021.

  2. American Cancer Society. Signs and Symptoms of Basal and Squamous Cell Skin Cancers. Updated July 26, 2019.

  3. Cancer Treatment Centers of America. Understanding how skin cancer is staged and graded. Updated July 16, 2021.

  4. American Cancer Society. Basal and squamous cell skin cancer stages. Updated July 26, 2021.

  5. American Academy of Dermatology Association. Skin cancer types: Squamous cell carcinoma symptoms. Updated 2021.

  6. Skin Cancer Foundation. Squamous cell carcinoma risk factors. Updated May 2019.

  7. American Cancer Society. Treating squamous cell carcinoma. Updated June 24, 2020.