Carr Dermatology: Squamous Cell Carcinoma: The Second Most Common Type of Skin Cancer

Squamous Cell Carcinoma (SCC) is the second most common type of skin cancer, second only to Basal Cell Carcinoma. It is so common that we see this type of skin cancer many times a day in our Sonoma County Dermatology practice here in Northern California.

What causes squamous cell carcinoma?

The very top upper layer of living cells in your skin is made up of squamous cells (this is your skin’s epidermis). Sun exposure causes damage to the DNA of these cells. A cell with DNA damage will then grow uncontrolled, which is what a cancer is. Like all cancer cells, this uncontrolled growth ultimately will invade and damage vital structures in the body like muscle and bone. Squamous cell carcinoma of the skin also has a small risk of spreading to lymph nodes and internal organs of the body. This is why it’s important to catch them early!

People with a lot of cumulative sun exposure tend to get SCCs. Some people are more prone to them than others including people with fair skin. Squamous cell skin cancers often start as “pre-cancers” called actinic keratoses. You may be familiar with the handy little liquid nitrogen gun that we dermatologists are infamous for using to spray-treat these pre-cancerous growths. We do this in an effort to prevent you from developing a squamous cell carcinoma.

Have you ever noticed that you usually get this treatment most often on those parts of your skin where you have had the most sun exposure over the years like your face, neck, ears and the back of our hands? These are areas with the telltale signs of sun damage such as wrinkles, broken blood vessels, thin skin, and sun freckles. Squamous cell skin cancers can also grow on any part of your skin, including inside the mouth, on the lips or genitals, your legs and feet, etc. Understand that it’s not just sun exposure that causes squamous cell cancers, but sun is the biggest cause and the most preventable cause.

What are the signs of squamous cell carcinoma?

A rough, pink bump
A sore that doesn’t heal
A scaly pink patch of skin
A rough growth under or next to the nails
A warty growth that pop up fast or grows like a horn and is tender

What is an actinic keratosis and how is it different than squamous cell carcinoma?

Squamous cell carcinoma often starts in a pre-cancerous form called an actinic keratosis. This is the most common skin problem we see here at Advanced Skin Care and Dermatology Physicians because, living in California, means being outside a lot in the sun. It’s impossible to know exactly what percentage of actinic keratoses turns into cancer but one study showed that anywhere from 6-10% of actinic keratoses turn into squamous cell carcinoma eventually.

If you do the math, that means that if you have 10 actinic keratoses, you could be guaranteed to get a skin cancer if you wait long enough! This is why we see our patients with actinic keratoses at least annually to do a full skin exam and treat all existing actinic keratoses. In our practice, we also teach our patients how identify these pre-cancers and skin cancers so that they know to come in if a worrisome spot appears on their skin between their appointments.

For most people, an actinic keratosis is often easier to feel than see. These pre-cancers feel like a rough patch of skin that never becomes smooth. The patch may be more irritated by sunscreen or other things that sting like lemon juice. They may turn redder than other skin in the sun. They often look pink, red and scaly. Occasionally, they are tan or flesh colored.

How can actinic keratosis be treated?

There are a few ways to treat actinic keratoses. Most often, your dermatologist will freeze them with liquid nitrogen, particularly if there are only a few to treat at one visit. In our practice, we also see people who have hundreds of actinic keratoses. In these cases, we can treat an area of skin that covers a larger area by prescribing medicated creams that inflame the pre-cancers to remedy them over a period of a month or two. People can use as a treatment called photodynamic therapy where a medicine is applied to the skin in the office and then “activated” by a special light. If you are a person who has had actinic keratoses in the past, please ask us about these options at your next visit!

Above all: Be proactive in protecting your skin from the sun!

Citrix SPF 40

Suntegrity 5-in-1 BB Cream

As dermatologists, we often feel like a broken record, but we honestly can’t emphasize the importance of utilizing sunscreen on a daily basis in ALL seasons. Dr. Bailey has made it really easy by creating a sunscreen comparison chart to find a trusted sunscreen that is an exact match for your skin. Dr. Bailey’s favorite everyday sunscreen is Citrix SPF 40 since it is invisible and layers well. The Suntegrity 5-in-1 BB Cream is another favorite for its natural, broad-spectrum mineral zinc oxide protection that feels and looks so good on your skin. Check out our complete list of recommended sunscreens here.

Let’s also not forget about sun protection accessories such as hats that really impact keeping your skin safe from the sun. Check out our Pinterest board for all types of ideas for keeping your skin protected while still remaining fashionable.

And, if you have any further questions, please don’t hesitate to call our office and schedule an appointment. I’ll gladly help you in any way I can!

Dr. Hayes completed her undergraduate studies at UCLA where she majored in Spanish Literature and graduated Magna Cum Laude. She went on to medical school at UCLA and then to a combined Dermatology and Internal Medicine residency at the University of Minnesota where she served as Chief Resident too. After years of schooling, she’s come back to Sonoma County to work with Advanced Skin Care Dermatology Physicians, Inc. as a Board Certified Dermatologist. When not “doctoring,” Dr. Hayes can be found with her three pets or the many Sonoma County friends and family that are happy that she has returned home.