What You Need to Know About the 3 Most Common Types of Skin Cancer

What you need to know about the most common types of skin cancer | Arizona DermatologyThe fact is, everyone is at risk for skin cancer, especially in the sunny state of Arizona. That’s why it’s especially important to familiarize yourself with the most common types of skin cancer. According to the American Cancer Society, the three most common types of skin cancer are basal cell carcinoma, squamous cell carcinoma, and malignant melanoma.

In this article, we’ll review the risk factors, symptoms, and treatment options for each cancer. We’ll also cover steps you can take to reduce your risk of skin cancer and keep your skin healthy for years to come.

1. Basal cell carcinoma

Basal cell carcinoma is the most common type of skin cancer, with over four million cases diagnosed in the United States each year. This cancer develops in the basal cells, which are located at the bottom of the epidermis, the outer skin layer. While this cancer rarely spreads to vital organs, it can cause nerve damage and disfigurement if it metastasizes.

Basal cell carcinoma is caused by ultraviolet (UV) radiation. In the case of basal cell carcinoma, the cancer often develops slowly after many years of intense sun exposure or use of tanning beds.

Risk factors

The main risk factor for basal cell carcinoma is exposure to UV rays. This risk is increased if you live in a sunny region, or somewhere at a high altitude. Patients who have had basal cell carcinoma before have a higher risk of developing another one, either in the same area or elsewhere on the body.

Signs and symptoms

Basal cell carcinoma typically resembles a red or brown scaly patch on the skin, or a white lump. The cancerous lesions may appear shiny or waxy. They’re also fragile, and can bleed easily.

Most often, one or more of the following characteristics are found in basal cell carcinoma lesions:

  • Open sores that won’t heal
  • Persistent red or irritated areas
  • Shiny bumps or nodules
  • Pink growths with elevated borders


Several treatment options are available for basal cell carcinoma. If the cancer is caught early, removing the cancer in a simple surgery may be the only treatment necessary. For larger tumors, techniques such as mohs therapy are used. Generally, treatments for basal cell carcinoma are completed in-office and do not require hospitalization.

2. Squamous cell carcinoma

Squamous cell carcinoma develops in the squamous cells. These cells make up the middle and outer layer of the skin. Squamous cell carcinoma is a slow growing cancer, and it is uncommon for it to spread. However, if left untreated, the cancer can spread to the lymph nodes and the tissue beneath the skin.

Risk factors

Similar to basal cell carcinoma, a major risk factor for squamous cell carcinoma is exposure to UV radiation. In particular, people who work outdoors or spend long periods of time in the sun are at an increased risk of developing squamous cell carcinoma.

Additional risk factors for squamous cell carcinoma include:

  • Light colored skin or eyes
  • Old age
  • Smoking
  • Weakened immune system

Signs and symptoms

While squamous cell carcinoma occurs most often on areas of the skin that are exposed to the sun, the cancer can occur anywhere on the body—including inside the mouth.

Signs of squamous cell carcinoma include:

  • A wart-like growth
  • A flat sore with a scaly crust
  • An open sore on the lip or mouth that won’t heal

Squamous cell carcinoma can resemble other forms of skin cancer, as well as other skin conditions. For a definitive diagnosis, consult a dermatologist.


Most often, squamous cell carcinoma is identified while the cancer is small, and can be treated with local methods such as surgery or prescription medication. However, if the cancer has spread to the lymph nodes, treatments such as radiation or chemotherapy may be needed.

3. Melanoma

Melanoma is the deadliest form of skin cancer. Melanoma occurs in the melanocytes, cells that are responsible for giving the skin its color. While it is less common than other types of skin cancer, it’s the most likely to grow and spread. If melanoma metastasizes, it can spread via the body’s lymph nodes to vital organs including the lungs, liver, and brain. This makes early detection and treatment crucial.

Similar to other types of skin cancer, melanoma is most often caused by exposure to UV radiation. However, because melanoma can occur in places on the body that are not exposed to sunlight, doctors believe that factors such as genetics and environmental factors can increase the chance of developing melanoma.

Risk factors

As with other forms of skin cancer, exposure to UV rays raises the risk of melanoma significantly. Melanoma lesions also arise from atypical moles. Patients with a large number of moles are at an increased risk of having one of their moles develop into a melanoma lesion. Patients with a family history of melanoma, or of other skin cancers, are also at an increased risk of developing melanoma.

Signs and symptoms

A major warning sign of melanoma is the formation of a suspicious mole on the skin, or an existing mole changing in color, shape, or size. While it is normal to develop new moles, acquired moles are more likely to become cancerous than moles you were born with.

Melanoma lesions can be identified using the ABCDE system.

  • Asymmetry: Melanoma lesions are often irregularly shaped, and not symmetrical.
  • Border irregularity: Moles with irregular, raised, or rough borders are characteristic of melanoma.
  • Color: While moles are usually brown, melanoma lesions can be black, blue, or red.
  • Diameter: If the mole is larger than ¼ of an inch, it may be a melanoma lesion.
  • Evolution: A mole that changes over time, or one that starts itching, bleeding, or oozing, can be a sign of melanoma.

If you notice one or more of these characteristics in your moles, schedule an appointment to have the mole evaluated.


Treatment of melanoma depends on the size of the cancer, and if it has spread to other parts of the body.  When caught early, melanoma is treated with a surgery to remove the cancer. Doctors may also recommend a lymph node biopsy to ensure that the cancer hasn’t spread. If the cancer is large, or has spread, radiation and chemotherapy may be used to treat the cancer.

How to reduce the risk of skin cancer

Because skin cancer is such a common condition, it’s understandable that many patients want to do as much as they can to reduce their risk. As dermatologists, here are four methods we recommend to our patients who are looking to reduce their risk of developing skin cancer.

1. Avoid tanning beds

The dangers of tanning beds are well-reported and have been studied extensively. According to the Skin Cancer Foundation, using a tanning bed just once before the age of 35 increases the risk of melanoma by 75%.

For a natural glow without the risk, consider spray tanning. At Arizona Dermatology, we use an oil-free, alcohol-free, and fragrance-free color matching system to protect your skin and deliver great results.

2. Protect yourself from the sun

Sun exposure is a major cause of skin cancer, so protecting yourself from the sun is critical. While many people wear sunscreen during the summer, it’s important to wear a sunscreen with at least SPF 30 all year round. Even when its cloudy, raining, or even snowing, the sun’s rays can still damage your skin. Protective clothing, such as wide-brimmed hats, should also be used to physically shield yourself from the sun.

3. Have a skin cancer screening

Early intervention and treatment is crucial in skin cancer cases. A yearly skin cancer screening with a dermatologist is the best way to detect skin cancer early, since dermatologists are trained to recognize the earliest warning signs.

If a suspicious growth or lesion is found during your screening, it will be biopsied to test for signs of cancer. If the biopsy comes back negative, no follow-up is necessary. If the biopsy comes back positive, your dermatologist will explain your treatment options and help you develop a clear plan for addressing the cancer.

4. Get to know your skin

Any changes to your skin, including new growths, sores that won’t heal, or changes to existing moles or freckles, should be brought to the attention of a dermatologist.

Evaluating your skin through regular self-exams will give you a baseline for what your skin is supposed to look like. That way, when any changes occur, you’ll be able to spot them easily.

Next steps

Arizona Dermatology has consistently been a leader in providing innovative methods for diagnosing and treating skin cancer. If you have a suspicious mole or lesion that you want to have evaluated, or have any other questions about skin cancer, we’re here to help. Contact us to schedule an appointment.