Skin cancer — the abnormal growth of skin cells — normally develops on skin exposed to the sun. But this common form of cancer can also occur on areas of your skin that are not usually exposed to sunlight.
Three major kinds of skin cancer are — basal cell carcinoma, squamous cell carcinoma, and melanoma.
You can minimize your risk of skin cancer by avoiding or limiting exposure to ultraviolet radiation. Checking your skin for any suspicious changes may help to detect skin cancer at its earliest stages. Early detection of skin cancer gives the greatest chance for successful skin cancer treatments.
Skin Cancer Types
- Basal cell carcinoma
- Nonmelanoma skin cancer
- Squamous cell carcinoma of the skin
Skin Cancer Symptoms
So where skin cancer develops?
Skin cancer develops mainly on the areas of sun-exposed skin, including the scalp, face, ears, lips, neck, arms, hands and chest, and on the legs in women. But it can also develop on areas that rarely see the light of the day like your palms, beneath your fingernails or toenails, and your genital area.
Skin cancer can affect people of all skin tones, including those with darker skin tones. When melanoma occurs in people with a dark complexion, it's more likely to occur in areas normally not exposed to the sun, like the palms of the hands and soles of the feet.
Basal cell carcinoma signs and symptoms
Basal cell carcinoma usually occurs in the areas of your body that are usually sun-exposed, such as your face or neck.
Basal cell carcinoma may appear as:
- A pearly or waxy bump
- A flat, flesh-coloured or brown scar-like lesion
- Bleeding or scabbing sore that heals and come back
Squamous cell carcinoma signs and symptoms
Most often, squamous cell carcinoma occurs on sun-exposed areas of your body, such as your ears, face, and hands. People with darker skin are more likely to develop squamous cell carcinoma in areas that aren't mostly exposed to the sun.
Squamous cell carcinoma may appear as:
- A firm, red nodule
- A flat bruise with a scaly, crusted surface
Melanoma signs and symptoms
Melanoma can develop anywhere on your body. Melanoma most often appears on the face or the trunk of affected men while in women, this type of cancer most often develops on the lower legs. In both men and women, melanoma can occur on skin that hasn't been exposed to the sun.
Melanoma can affect people of any skin complexion. In people with a darker complexion, melanoma tends to occur on the palms or soles, or under the fingernails or toenails.
Melanoma signs include:
- A large brownish spot with darker speckles
- A mole that changes in size, colour, or feels or which bleeds
- A small lesion with an irregular border and portions that appear pink, white, blue, red, or blue-black
- A painful lesion that itches or burns
- Dark lesions on your palms, soles, fingertips or toes, or on mucous membranes lining your mouth, nose, anus or vagina
Signs and symptoms of rare skin cancers
Other, few less common types of skin cancer include:
Kaposi sarcoma. This form of skin cancer develops in the skin's blood vessels and causes purple or red patches on the skin or mucous membranes.
It mainly occurs in people who have weak immune systems, such as people with AIDS, and in people taking medications that suppress their natural immunity.
- Merkel cell carcinoma. Merkel cell carcinoma causes firm, shiny nodules which occur on the skin and in hair follicles. Merkel cell carcinoma is mostly found on the head, neck, and trunk.
- Sebaceous gland carcinoma. This rare and aggressive cancer arise in the oil glands in the skin. Sebaceous gland carcinomas — which usually appear as hard, painless nodules — can develop anywhere, but mostly occur on the eyelid, where they're frequently mistaken for other eyelid problems.
Factors that may increase your risk of any type of skin cancer include:
- Fair skin. Anyone, regardless of skin complexion, can get skin cancer. However, having less pigment (melanin) in your skin provides less protection from damaging ultraviolet radiation. If you have blond or red hair and light-coloured eyes, and you are easily prone to freckle or sunburn, you're much more likely to develop skin cancer than a person with a darker complexion.
- A history of sunburns. Having one or more sunburns as a child or teenager increases your risk of developing skin cancer as an adult.
- Excessive sun exposure. Anyone who spends too much time in the sun may develop skin cancer, especially if the skin isn't protected by clothing or sunscreen. A tan is your skin's response to excessive UV radiation.
- Sunny or high-altitude climates. People who live in extremely sunny, warm climates are exposed to more sunlight than people who live in colder climates. Living at higher altitudes, where the sunlight is strongest, also exposes you to more radiation.
- Moles. People who have abnormal moles called dysplastic nevi are at increased risk of skin cancer. These abnormal moles which look irregular and are generally bigger than normal moles are more likely to become cancerous. If you have a history of abnormal moles, observe them regularly for changes.
- Precancerous skin lesions. Having skin lesions known as actinic keratoses can surge your risk of developing skin cancer. These precancerous skin growths typically appear as rough and scaly patches that range in colour from brown to dark pink. They're most common on the face, head, and hands of fair-skin toned people whose skin has been sun-damaged.
- A family history of skin cancer. If any of your parents or a sibling has or had skin cancer, you may have a risk of the disease.
- A personal history of skin cancer. If you developed skin cancer once in life, you're at risk of developing it again.
- A weakened immune system. People with weak immune systems are at a greater risk of developing skin cancer. This includes people living with AIDS and those who are taking immunosuppressant drugs after an organ transplant.
- Exposure to radiation. People who got radiation treatment for skin conditions such as eczema and acne may have more risk of skin cancer, particularly basal cell carcinoma.
- Exposure to certain substances. Exposure to certain substances, like arsenic, may increase your risk of skin cancer.
When to see a doctor?
Make an appointment with your doctor if you notice any changes to your skin which is of concern to you. All skin changes are not necessarily caused by skin cancer. Your doctor will investigate your skin changes to determine the cause of the changes.
This article is only for educational purposes and is not intended to be a substitute for medical treatment by a healthcare professional.