What Is Skin Cancer?
The skin is the body’s largest organ. Skin has several layers, but the two main layers are the epidermis (upper or outer layer) and the dermis (lower or inner layer). Skin cancer begins in the epidermis, which is made up of three kinds of cells—
Squamous cells: Thin, flat cells that form the top layer of the epidermis.
Basal cells: Round cells under the squamous cells.
Melanocytes: Cells that make melanin and are found in the lower part of the epidermis. Melanin is the pigment that gives skin its color. When skin is exposed to the sun, melanocytes make more pigment and cause the skin to darken.
Basal and squamous cell carcinomas are the two most common types of skin cancer. They begin in the basal and squamous layers of the skin, respectively. Both can usually be cured, but they can be disfiguring and expensive to treat.
Melanoma, the third most common type of skin cancer, begins in the melanocytes. Of all types of skin cancer, melanoma causes the most deaths because of its tendency to spread to other parts of the body, including vital organs.
Most cases of skin cancer are caused by overexposure to ultraviolet (UV) rays from the sun, tanning beds, or sunlamps. UV rays can damage skin cells. In the short term, this damage can cause a sunburn. Over time, UV damage adds up, leading to changes in skin texture, premature skin aging, and sometimes skin cancer. UV rays also have been linked to eye conditions such as cataracts.
What types of Skin Cancer are there?
- Basal cell carcinoma (BCC)
This is the most common type of skin cancer.
BCC frequently develops in people who have fair skin. People who have skin of color also get this skin cancer.
BCCs often look like a flesh-colored round growth, pearl-like bump, or a pinkish patch of skin.
BCCs usually develop after years of frequent sun exposure or indoor tanning.
BCCs are common on the head, neck, and arms; however, they can form anywhere on the body, including the chest, abdomen, and legs.
Early diagnosis and treatment for BCC are important. BCC can grow deep. Allowed to grow, it can penetrate the nerves and bones, causing damage and disfigurement.
- Squamous cell carcinoma (SCC) of the skin
SCC is the second most common type of skin cancer.
People who have light skin are most likely to develop SCC. This skin cancer also develops in people who have darker skin.
SCC often looks like a red firm bump, scaly patch, or a sore that heals and then re-opens.
SCC tends to form on skin that gets frequent sun exposure, such as the rim of the ear, face, neck, arms, chest, and back.
SCC can grow deep into the skin, causing damage and disfigurement.
Early diagnosis and treatment can prevent SCC from growing deep and spreading to other areas of the body.
SCC can develop from a precancerous skin growth
Some people develop dry, scaly patches or spots on their skin called actinic keratoses (AKs). Also caused by too much sun, an AK isn’t skin cancer. An AK is a precancerous skin growth that can turn into a common type of skin cancer, squamous cell carcinoma.
People who get AKs usually have fair skin.
AKs usually form on the skin that gets lots of sun exposure, such as the head, neck, hands, and forearms.
Because an AK can turn into a type of skin cancer, treatment is important.
Melanoma is often called "the most serious skin cancer" because it has a tendency to spread.
Melanoma can develop within a mole that you already have on your skin or appear suddenly as a dark spot on the skin that looks different from the rest.
Early diagnosis and treatment are crucial.
Knowing the ABCDE warning signs of melanoma can help you find an early melanoma.
- Cutaneous T-cell lymphoma (CTCL) is a rare type of blood cancer.
It begins in a type of white blood cell called the T-lymphocyte (T-cell). T-cells help prevent infections and other diseases.
As odd as it sounds, most T-cells are found in our skin. That’s because our skin is the first line of defense against disease. The surface of an adult’s skin contains about 20 billion T-cells. That’s nearly twice as many T-cells as found in other parts of the body.
There are many types of CTCL. More than half the people who develop CTCL will have one of the following types:
Mycosis fungoides is the most common type of CTCL. This type tends to worsen very slowly. It can stay in its earliest stage, which often looks like rash, for years. In this stage, the cancer is often difficult to diagnose because it tends to looks like eczema or psoriasis. These conditions are much more common than CTCL.
Sézary syndrome is more aggressive. It can also look like eczema. Some people develop red and swollen skin over much of their body. Their skin may feel hot, sore, and extremely itchy.
The other types of CTCL are very rare.
- Dermatofibrosarcomaprotuberans (DFSP) is a rare skin cancer.
It begins in the middle layer of skin, the dermis. DFSP tends to grow slowly. It seldom spreads to other parts of the body.
Because DFSP rarely spreads, this cancer has a high survival rate. Treatment is important, though. Without treatment, DFSP can grow deep into the fat, muscle, and even bone. If this happens, treatment can be difficult.
The first sign of this skin cancer is often a small bump on the skin. It may resemble a deep-seated pimple or rough patch of skin. DFSP can also look like a scar. In children, it may remind you of a birthmark.
- Merkel cell carcinoma (MCC) is a rare skin cancer.
Although MCC is rare, cancer data also show that more people are developing this skin cancer than ever before.
Many people aged 65 and over rarely protect their skin from the sun.
Studies show that almost everyone who develops IBC is aged 50 and over. Most of them also have fair skin and rarely protect their skin from the sun.
- Sebaceous gland carcinoma (SC) is a rare skin cancer.
It is considered an aggressive skin cancer because it can spread.
If detected and treated early, treatment is often successful. It is useful to know the following:
Most SC starts on the eyelid.
You may notice a painless, round, tightly adherent lump on the upper or lower eyelid.
Sometimes you have to gently pull on the eyelid to see the lump.
How to find Skin Cancer?
Skin cancer diagnosis always requires a skin biopsy.
The procedure that your dermatologist uses to remove the spot is called a skin biopsy. Having a skin biopsy is essential. It's the only way to know whether you have skin cancer. There's no other way to know for sure.
What Skin Cancer looks like?
Skin cancer appears differently on the body. It can look like:
- An altered mole or a mole that looks different to others
- An unhealing wound or a wound that heals and reappears
- A brown or black stripe under the nail
- Cancer may also manifest in other ways.
You don't need to memorise a long list to spot skin cancer on your body. Dermatologists put it this way. It's time to see a dermatologist if you notice a spot on your skin that -
Who is at risk of Skin Cancer?
Anyone can get skin cancer, but people with certain characteristics are at greater risk:
- A lighter natural skin color.
- Skin that burns, freckles, reddens easily, or becomes painful in the sun.
- Blue or green eyes.
- Blond or red hair.
- Certain types and a large number of moles.
- A family history of skin cancer.
- A personal history of skin cancer.
- Older age.
How to prevent Skin Cancer?
Skin cancer prevention requires a comprehensive approach to protecting yourself against harmful UV radiation.
That’s because UV radiation from the sun isn’t just dangerous, it’s also sneaky. Not only can it cause premature aging and skin cancer, it reaches you even when you’re trying to avoid it – penetrating clouds and glass, and bouncing off of snow, water and sand. To prevent skin cancer :
- Stay in the shade.
- Wear clothing that covers your arms and legs.
- Wear a hat with a wide brim to shade your face, head, ears, and neck.
- Wear sunglasses that wrap around and block both UVA and UVB rays.
- Use a broad spectrum sunscreen with a sun protection factor (SPF) of 15 or higher.
What treatments are available when Skin Cancer is detected?
- Surgery, laser and light treatments and radiation therapy.
Medicines: Local treatments and drugs that are injected, intravenously or taken orally.
To repair superficial skin damage, the physician applies trichloroacetic acid and/or similar chemicals to the face, causing the top skin layers to slough off. New skin generally regrows within a few weeks. This method may require local anesthesia. It can cause temporary irritation and discoloration.
A chemical peel can be used to remove superficial facial actinic keratoses (precancerous skin lesions), especially when previous treatments have not succeeded. It is also used as a cosmetic skin rejuvenation technique.
The dermatologist uses a beam of light of a specific wavelength to destroy skin precancers as well as certain superficial skin cancers. Some lasers vaporize (ablate) the skin cancer, while others (nonablative lasers) convert the beam of light to heat, which destroys the tumor. Ablative lasers (such as CO2 lasers) give the physician good control over the depth of tissue removed, without causing bleeding. The doctor may remove the skin’s outer layer and/or variable amounts of deeper skin, so local anesthesia may be needed. The risks of scarring and pigment loss are slightly greater than with other techniques.
Laser surgery is effective for removing precancerous actinic keratoses from the face and scalp, and precancerous actinic cheilitis from the lips. It can also be used to treat superficial basal cell carcinomas and, in rarer instances, superficial squamous cell carcinomas. In addition, it can serve as a secondary therapy when topical medications or other techniques are unsuccessful.
Radiation, directing low-energy X-ray beams to destroy the tumor, is sometimes used to treat basal cell or squamous cell carcinomas that are hard to manage surgically and for elderly patients or others in poor health. It may require several treatments over a few weeks or daily treatment for a month. Cure rates are around 90 percent. Although radiation limits damage to adjacent tissue, it can involve long-term cosmetic problems and radiation risks.
Physicians may combine radiation with other treatments for advanced squamous cell carcinoma. Radiation is also being tested in combination with certain treatments for advanced melanoma.
To eliminate skin precancers or cancers, the dermatologist applies a topical agent to the make the lesions and the areas surrounding them sensitive to light. The patient waits for an hour or more to let this absorb into the skin. The dermatologist then uses a strong blue or red light or laser (or sometimes controlled natural sunlight) to activate these medicated areas. This selectively destroys lesions while causing minimal damage to surrounding healthy tissue. Some redness, pain, peeling, flaking and swelling can result. After the procedure, patients must strictly avoid sunlight for at least 48 hours, as UV exposure will increase activation of the medication and may cause severe sunburns.
Photodynamic therapy (PDT) is FDA-approved for the treatment of precancerous lesions called actinic keratoses (AKs) and is especially useful for widespread AKs on the face and scalp. It is sometimes used for superficial basal cell carcinomas or squamous cell carcinomas.
Using a scalpel, the physician removes, or excises, the entire cancerous tumor along with a surrounding border of presumably normal skin as a safety margin, then sends the tissue specimen to a lab to make sure the margins are free of cancer. Depending on its size and location, the wound may be left open to heal or the doctor may close it with stitches. If the lab finds evidence of skin cancer beyond the safety margin, the patient may need to return for another surgery.
Excisional surgery can be used for basal cell carcinomas and squamous cell carcinomas as well as melanomas. For tumors discovered at an early stage that have not spread beyond the tumor margin, excisional surgery is frequently the only treatment required.
- Curettage and Electrodesiccation
This technique can be used for both actinic keratoses (skin precancers) and certain skin cancers. Using local anesthesia, the physician scrapes off part or all of the lesion with a curette, an instrument with a sharp ring-shaped tip. Then the doctor uses electrodesiccation, which cauterizes the area with heat or a chemical agent to stop the bleeding and destroy any residual abnormal cells that the curette did not remove. When treating a skin cancer, the doctor may repeat the entire procedure twice at the same session.
While curettage and electrodesiccation can be used to remove actinic keratoses as well as some superficial basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs), it is usually not recommended for larger, aggressive or invasive BCCs or SCCs or for lesions on the face. The treated area may not regain its pigment.
Are all moles cancerous?
Most moles are not cancerous. Some moles are present at birth, others develop up to about age 40. Most adults have between 10 and 40 moles.
In rare cases, a mole can turn into melanoma. If you have more than 50 moles, you have an increased chance of developing melanoma.
How does Skin Cancer become a life-threatening cancer?
You may wonder how cancer on the surface of your skin becomes a life-threatening cancer. It seems logical to think you could just scrape off the skin with the cancer cells or even remove the cancerous skin lesion with a minor skin surgery and that’s all that would be needed. These techniques are successfully used if cancer is caught early.
But if skin cancer isn’t caught early, something that’s “just on my skin” can grow and spread beyond the immediate area. Cancer cells break away and travel through the bloodstream or lymph system. The cancer cells settle in other areas of your body and begin to grow and develop into new tumors. This travel and spread is called metastasis.
The type of cancer cell where cancer first started — called primary cancer — determines the type of cancer. For example, if malignant melanoma metastasized to the lungs, the cancer would still be called malignant melanoma. This is how that superficial skin cancer can turn into life-threatening cancer.