How Fast Does Squamous Cell Carcinoma Spread?

Being diagnosed with squamous cell carcinoma (SCC), a common type of skin cancer, can be overwhelming. Many people wonder how fast SCC metastasizes (spreads).

Fortunately, SCC is usually considered a slow-growing cancer and often doesn’t spread to other areas of the body. However, there are different types of SCC, and some forms can be more aggressive, especially when left untreated. Some people may have a higher risk of metastasis, including those with weakened immune systems.

If you or a loved one has been diagnosed with SCC, learning more about your prognosis (outlook) can help you feel more informed and know what to expect. In this article, we’ll explain how fast SCC spreads and where, risk factors for aggressive spread, and how to improve your prognosis.

How Does Squamous Cell Carcinoma Spread?

Most cases of SCC tend to grow slowly, and metastasis is rare. The exact percentage depends on the type of SCC and how high-risk it is. Researchers have found that about 3 percent to 9 percent of SCC cases metastasize to other areas of the body.

If SCC does spread, it’s most often found within the first few years after the cancer is diagnosed, so follow-up visits are important.

SCC begins in the squamous cells, which are found in the middle and outer layers of the epidermis (the skin’s outer layer). When the DNA in these cells becomes damaged, the cells can begin to grow and multiply too quickly.

If the cancer cells break away from the original tumor and invade nearby tissues or travel to other parts of the body, the cancer has metastasized.

SCC often develops on areas of the body that receive the most sunlight, including the face, ears, and backs of hands. However, SCC can develop anywhere on the body, including areas that don’t receive much sun exposure.

People who sunburn easily are at a higher risk of developing SCC, especially those with lighter skin and hair. In people with darker skin, SCC is more likely to form in areas that are not exposed to the sun.

Untreated Squamous Cell Carcinoma

Untreated SCC can spread to nearby lymph nodes (small glands that help the body fight infection) and surrounding tissues.

The most common sites where SCC may spread include:

• Parotid lymph nodes (located near the ear)
• Cervical lymph nodes (located in the neck)
• Axillary lymph nodes (located under the arms)
• Groin lymph nodes (located in the groin area)

When SCC spreads, it most often first goes to nearby lymph nodes. For cancers on the head and neck, this may include lymph nodes near the parotid gland and those in the neck.

Most SCC develops on sun-exposed skin, like the face and ears. SCC that starts on the ear can carry a higher risk of spreading than SCC in some other locations. However, SCC usually spreads first to nearby lymph nodes rather than directly to other organs.

In rare cases, SCC can become life-threatening if it’s not treated.

Squamous Cell Carcinoma Symptoms and Stages

Healthcare providers consider how far cancer has spread when determining your cancer stage. A cancer stage describes how large the tumor is and whether it has spread to nearby tissues, lymph nodes, or other parts of the body. The signs and symptoms can change as SCC progresses.

You may see stages written with Roman numerals, such as stage III for stage 3.

Risk Factors for Spreading Squamous Cell Carcinoma

For most people, SCC has an excellent outlook when it’s found and treated early. However, about 5 percent to 10 percent of cases are considered aggressive and have a higher chance of spreading.

Certain features can indicate that SCC is more aggressive. It may be considered high-risk if:

• It develops on the lip or ear.
• The tumor is wider than 2 centimeters or deeper than 4 millimeters into the skin.
• The tumor grows through the layer of fat under the skin or affects nearby nerves.

Tumors are more likely to spread if they’ve been classified as “poorly differentiated” (cancer cells that look very different from healthy cells under a microscope) or “desmoplastic” (tumors with dense tissue resembling scarring).

People who have had SCC in the past and experience a recurrence (when the cancer comes back) are at higher risk for metastasis.

Additionally, people who are immunocompromised (have weakened immune systems) are also at higher risk. This means the immune system can’t function properly and may be less able to recognize and fight cancer cells. A person’s immune system may be weakened by a chronic health condition or certain medications.

SCC can sometimes grow quickly. Fast-growing tumors may change rapidly over weeks or months. This may be more likely in people who are immunocompromised or who have a genetic predisposition (an inherited increased risk) to skin cancer.

Having a family history of skin cancer may also increase the risk of developing aggressive SCC.

How To Improve Your Squamous Cell Carcinoma Prognosis

Talk with your healthcare provider about your treatment plan and ways to improve your prognosis. Fortunately, there are treatment options for every stage of SCC.

Consider taking the following actions to improve your prognosis and reduce the risk of cancer recurrence:

• Use sun protection — Most DNA damage that leads to skin cancer comes from the sun’s ultraviolet (UV) rays. Help protect your skin by wearing sunscreen, a wide-brimmed hat, sunglasses, and protective clothing.
• Avoid tanning beds — Tanning beds expose your skin to harmful UV rays.
• Annual skin checks — See your dermatologist yearly for a professional skin cancer examination. Early diagnosis can improve your prognosis.
• Perform self-exams — Checking your skin for any changes can help you recognize warning signs as early as possible.
• Ask your dermatologist about prescription creams — Certain topical treatments may help treat precancerous lesions (areas of abnormal skin growth) and reduce the risk of future SCC in some people.

Treatment Options for Aggressive SCC

The treatment for SCC depends on several factors, including the size and location of the tumor and whether the cancer has spread.

For many small SCC tumors that haven’t spread, surgery is often the main treatment. In some people with higher-risk SCC, doctors may also use genetic testing to help estimate the risk that the cancer could metastasize.

Mohs micrographic surgery is one of the most effective treatment options for many people with high-risk SCC. During Mohs surgery, the surgeon removes one thin layer of skin at a time and examines it under a microscope to look for cancer cells. This process continues until no cancer cells remain.

Mohs surgery has very high success rates, especially for high-risk SCC or SCC in areas where preserving as much healthy skin as possible is important. These may include the face, ears, lips, eyelids, or hands.

If SCC has spread or cannot be completely removed with surgery, treatment may include surgery, radiation therapy, or both. Some people may also receive immunotherapy (medicines that help the immune system recognize and fight cancer cells).

In some cases, chemotherapy or targeted therapy may be used if immunotherapy is not effective or is not an option.

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On MySkinCancerTeam, people share their experiences with nonmelanoma types of skin cancer, get advice, and find support from others who understand.

What stage was your squamous cell carcinoma when you were diagnosed? Has it spread since then? Let others know in the comments below.