Skin Cancer: Causes, Signs, and Prevention
The skin is the body’s largest organ, and it plays a number of important roles. From protecting against infection to regulating your body temperature, your skin does a lot more than you realize.
And your skin is constantly exposed to danger. That’s why it isn’t surprising that skin cancer is the most common cancer in the United States. More than three million Americans are diagnosed with skin cancer each year, and it’s estimated that one in five Americans will develop skin cancer at some point in their lives.
Skin cancer can affect anyone, regardless of age, race, or ethnicity. To protect yourself and minimize your risk, here are the facts about this deadly condition.
What is Skin Cancer?
Skin cancer is the abnormal, uncontrolled growth of skin cells.
Most skin cancers emerge from the epidermis, which is the outer layer of skin. Skin cancer most often develops in areas that see high amounts of sun exposure to the sun – like the scalp, face, and upper and lower extremities. But skin it can also occur in areas of your skin that aren’t ordinarily exposed to sunlight, including the palms, underneath toenails or fingernails, and even the genital area.
The most common types of skin cancer are basal cell carcinoma, squamous cell carcinoma, and melanoma. All three types of skin cancers derive from the epidermis. Basal cell carcinoma comes from basal cells, squamous cells arrive from keratinocytes, and melanoma arises from melanocytes. Melanocytes produce melanin, which is the pigment that gives skin its color.
No matter the type, skin cancers are considered malignant. This means they have the potential to spread or metastasize to other parts of the body.
How Common is Skin Cancer?
As mentioned previously, skin cancer is incredibly common. In fact, it’s so common that you likely know people who’ve had it – whether they’ve had the cancerous cells or spots removed, or if they’ve undergone treatments for the condition.
Among the millions of individuals with skin cancer, almost 80 percent of all skin cancers are basal cell cancers. Nearly 20 percent of skin cancers are squamous cell cancers. Squamous cell cancers having a greater chance of spreading to other parts of the body than basal cell cancers.
However, both of these skin cancers tend to grow slowly. As a result, both types are rarely fatal if detected early and treated properly. When caught and treated, cure rates are near 95 percent for both.
Although melanoma is much less commonly diagnosed than basal cell and squamous cell carcinomas, it’s much more likely to spread to other parts of the body than the other two common types of skin cancer. As a result, melanoma is much more serious diagnosis, accounting for the lion’s share of deaths from skin cancer.
What Causes Skin Cancer?
To put it simply, there’s one big factor that causes skin cancer: exposure to UV light. Frequently exposing your skin to these damaging rays can cause cancerous lesions or tumors.
Most skin cancers arise from mutations in the DNA of skin cells. And these mutations are caused by exposure to UV light from the sun. Other less common causes of mutations in skin cells are exposed to high levels of radiation (e.g., X-rays) and contact with certain chemicals (e.g., arsenic). It’s these mutations that cause skin cells to grow uncontrollably, leading to cancerous cells that grow into tumors.
There are a number of risk factors that may increase your odds of developing skin cancer. And while one of the biggest is exposure to UV light, particularly from the sun, other risk factors can be less obvious. Common risk factors include moles, precancerous lesions (like actinic keratoses), a family or personal history of skin cancer, use of tanning beds, and a weakened immune system.
Melanoma has a high genetic component and many times can arise in non-sun-exposed skin. BCC and SCC typically are seen in sun-exposed skin.
How Do I Protect Myself from Skin Cancer?
Most skin cancers are potentially preventable. You should avoid the sun, especially between the hours of 10 a.m. and 4 p.m., and seek shade. In addition, the use of sunglasses (that block both UVA and UVB rays), year-round broad-spectrum water-resistant sunscreen of at least 30 SPF, and protective clothing like a hat with a broad brim and long sleeve shirts made from dark, tightly woven fabrics can provide great protection from the sun’s damaging UV rays. It is also highly recommended to avoid tanning beds.
The American Academy of Dermatology recommends checking your skin regularly for new growths or changes in existing moles and reporting any significant changes to your doctor.
What Does Skin Cancer Look Like?
Because there are several types of skin cancer, the appearance of cancerous tumors can vary.
However, the warning signs of all types of skin cancer may include changes in the size, shape, or color of a mole or other lesions, the appearance of a new growth on the skin, or a sore that doesn’t heal or bleeds.
Basal cell carcinoma may appear as a pearly bump, a flat pink or flesh-colored lesion, or a bleeding or scabbing non-healing sore. Often, they can look like a blemish that won’t go away.
Squamous cell carcinoma may appear as a slow-growing firm red nodule or a flat lesion with a scaly surface. There is a variant of squamous cell carcinoma called a keratoacanthoma that grows quickly, in a matter of weeks.
How Can I Spot the Signs of Skin Cancer?
Since melanoma is the deadliest of all skin cancers, everyone should pay special attention to its potential signs. To do this, you should follow the “ABCDE rule.” Here’s what that means:
- A stands for “asymmetry” – one half of the mole does not match the other half
- B stands for “border irregularity” – edges of a mole are ragged, notched, or blurred
- C stands for “color” – a mole has pigmentation that isn’t uniform
- D stands for “diameter” – any mole that’s greater than 6 millimeters, or the approximate size of a pencil eraser
- E stands for “evolution” – if you notice any change in a mole’s appearance over time
Make sure to monitor your skin for these changes, whether they happen to moles you already have or new growths. Any skin changes should be something you note with your doctor or dermatologist.
When to See a Doctor About Skin Cancer
Since monthly self-monitoring of your skin is recommended, any changes in skin lesions over a month or more should be brought to a healthcare professional’s attention. But keep in mind that not all skin changes are cancerous. Your doctor will determine the best course of action, whether it be an observation or a biopsy of the suspicious lesion.
Skin cancer is by far the most common of all human cancers. Although it can be frightening, it’s largely a preventable – and treatable – disease with a positive prognosis.