Skin cancer is the uncontrollable growth of abnormal skin cells from any of the layers that make up the skin. It one of the most common cancers in the world and it affects people of all skin types.
It mostly affects areas of the skin exposed to the sun like neck, face, ears, lips, arms & on the legs of women. But it can also occur on other areas of the body like genital area, palms of the hand & beneath your nails
Most cases of skin cancer are caused by skin damage that happens from so much exposure to the sun. This damage can happen over a long period of time.
Most people with a history of overexposure to the sun during childhood years have a greater risk of developing both Basal cell carcinoma and Squamous cell carcinoma. Also, since people are living longer, it is assumed they will be exposed to more sunlight over their lifetime.
The skin is made up of 2 main layers: the epidermis on the outside and the dermis under. Skin cancer usually begins in your skin’s top layer known as epidermis. The epidermis is made up of the following cells:
- Squamous cells is the thickest layer of the epidermis which lies just below the outer surface and act as the skin’s inner lining.
- Basal cells, which produce new skin cells, sit beneath the squamous cells.
- Melanocytes — which produce melanin, the pigment that gives skin its normal colour. They are located in the lower part of your epidermis.
Types of skin cancer
Basal cell carcinoma (BCC)
Basal cell carcinoma (BCC) usually affects the areas of the body that is most exposed to sunlight or UV radiation such as your neck or face.
It is sometimes called a rodent ulcer or may look like a sore that won’t heal. Most BCC does not usually spread to other parts of the body and most people are always cured after treatment. However some can be fast growing and may spread into the bones.
Squamous cell carcinoma (SCC)
Squamous cell carcinoma (SCC) starts from the squamous cells, that make up the middle and outer layers of the skin. It also affects the sun-exposed parts of the body. Meanwhile, people with darker skin are more likely to develop SCC on areas that aren’t often exposed to the sun.
Squamous cell carcinoma (SCC) may appear as appears as a firm red nodule, flat sore with a scaly crust, a red sore or rough patch inside your mouth or red, raised patch or warlike sore on or in the anus or on your genitals
Melanoma
Melanoma (also called malignant melanoma) is a cancer that usually starts from the melanocytes. They are usually more aggressive than the other two types of skin cancer. It can start in a normal looking skin or from an existing mole which then becomes cancerous.
It is important to identify and treat melanoma as early as possible because it can spread deeper into layers of the skin. Also, if Melanoma cells (melanocytes) get into the lymphatic system or the blood, they can move easily into other parts of the body. There are four different types of melanoma. They are Superficial spreading melanoma, Nodular melanoma. Lentigo maligna melanoma and Acral lentiginous melanoma.
The appearance of a new mole or a change in an existing mole is the most common sign of melanoma. Other signs include:
- A large brownish spot with darker speckles
- Dark lesions on your palms, soles, fingertips or toes, or on mucous membranes lining your mouth, nose, vagina or anus
- A small lesion with an irregular border and portions that appear red, pink, white, blue or blue-black
- A painful lesion that itches or burns
Symptoms of skin cancer
The symptoms of skin cancer will depend on the type of skin cancer.
- For Basal cell carcinoma, the symptoms may include a lump which appears like a smooth and pearly and waxy, a brown or black lump in dark skins, a non-healing scar, a from lump that may look sunken in the middle, a sore or lump which itches and bleeds, or grow into a painless ulcer.
- For Squamous cell carcinoma, the cancer may have a hard, crusty scab, a firm red nodule, and may bleed sometimes.
- For Melanoma, symptoms include a mole that changes colour or shape, bleeds, a lesion that itches and has irregular borders.
- For Merkel cell carcinoma, symptoms may appear as firm, shiny nodules that occur on or just beneath the skin and in hair follicles. Merkel cell carcinoma is most often found on the head, neck and trunk.
Causes/risk factors of skin cancer
Most skin cancers are caused by damage to the sun-Ultraviolet (UV) light. However other factors can increase the risk.
Ultraviolet (UV) light
UV light from too much sun exposure or tanning lamps/sunbeds causes damage in the DNA of the skin cells which causes skin cancer. Being exposed to too much UV light as a child or staying too much in the sun will significantly increase the risk of getting skin cancer. Avoid the sun when it is at its strongest to avoid sunburns and skin damage.
Moles
People who have many moles or abnormal moles are at increased risk of skin cancer. If you have a history of abnormal moles, you will need to check them regularly for changes.
Bowen’s disease
This is caused by abnormal growth of cells in the epidermis. If left untreated, it may develop into SCC
Weak immunity
People with a weakened immune system have a higher risk of developing skin cancer. For example, those who have HIV or those that are taking immunosuppressants.
Genetic conditions
People with certain genetic conditions like Gorlin syndrome have an increased risk of developing cancer.
Skin colour
Having less pigment (melanin) in your skin provides less protection from damaging UV radiation.
Previous radiation treatment
Having previous radiation treatment on the skin can increase the risk of getting skin cancer.