Radiation Therapy for Skin Cancer

Types of Skin Cancer

Broadly, skin cancers can be divided into melanoma and non-melanoma skin cancers (NMSC). However, each specific type can have distinctive features.

Basal cell carcinoma (BCC)

Basal cell carcinomas are the most common type of skin cancer, accounting for almost 75 percent of all new skin cancer diagnoses.
BCC develops from cells located deep in the epidermis, which is the outermost layer of the skin.
They usually occur on sun-exposed areas, such as the nose and the ears but can be anywhere on the skin. They can even develop in areas that are never exposed to the sun.
Individuals at highest risk are those with fair skin, and light hair and eyes, who had early, intermittent, intense exposure to sun usually resulting in a sunburn.
Basel cell carcinomas are typically slow growing tumors, which can be very destructive locally but rarely spread (metastasize) to other parts of the body.

Squamous cell carcinoma (SCC)

Squamous cell carcinoma is the second most common type of skin cancer.
These skin cancers develop from squamous cells located in the middle layer of the epidermis, which is the outermost layer of the skin.
Similarly to basal cell carcinoma, sun/UV light exposure is the most common risk factor. They can also arise in areas of previous trauma, scars, burn injuries or inflammatory conditions.
They can be either slowly-growing or rapidly-growing tumors, they can invade surrounding structures, and they may spread (metastasize) to other parts of the body.

Malignant melanoma

Melanoma is not as common as basal cell and squamous cell carcinoma, but it is still the sixth most common malignancy among all other cancers.
These cancers develop from skin cells called melanocytes that produce brownish or reddish pigment (melanin), which gives skin its color.
Sun and UV light exposure, particularly if combined with having fair or light skin color, is the most common risk factor.
This is the most serious type of skin cancer, because it can be very aggressive and spread rapidly to other parts of the body.

Other skin cancers

Merkel cell carcinoma: These cancers develop from cells in the skin that allow us the sensation of touch (called tactile receptors). They are located in the dermis, which is the deeper layer of the skin. They can be quite aggressive and are more likely to spread to other parts of the body.
Sebaceous, apocrine or eccrine cell carcinoma: These cancers develop from the different types of sweat glands, located in the skin dermis. They can behave aggressively.