Actinic keratoses (AK’s) are pre-malignant changes in the skin characterized by persistent, red, scaly areas. While they may be rubbed off and seem to disappear, they will recur in the same areas within a few weeks. They occur predominantly on areas of the skin that have had significant sun exposure including the face, scalp, neck, chest, hands, and forearms. Actinic keratoses are most commonly treated with cryotherapy (freezing with liquid nitrogen), topical anti-cancer agents such as 5- fluorouracil and imiquimod, photodynamic therapy, or ablative laser resurfacing. Good sunscreens and minimizing sun exposure are important in the prevention of these lesions which are precursors to squamous cell carcinoma.
Basal Cell Carcinoma
Basal cell carcinoma is the most common form of skin cancer with more than one million occurring in the United States annually. They are the result of significant sun exposure. More than 90% occur on predominantly sun exposed areas. Basal cell carcinomas rarely metastasize or spread, but they do not go away on their own. They are locally destructive to surrounding tissue and can cause loss of an ear, nose, etc., if left untreated.
Basal cell carcinomas are usually slow growing. They may present as a small pimple-like growth with a fine, pearly border, as a shiny persistently pink area, a scar, a depression, or as a sore that will not heal. They may or may not be pigmented.
Basal cell carcinomas have a high cure rate. The type of basal cell carcinoma, the size, and location are all used to determine the most appropriate treatment. Biopsy of a suspected lesion will help decide the best method of treatment. Treatment could include electrodessication and curettage (removal by scraping and cauterizing with an electric needle), which is the most tissue sparing, surgical excision, cryosurgery (freezing with liquid nitrogen), topical anti-cancer agents, Mohs micrographic surgery, or radiation therapy.
Studies show that a person who develops one basal cell carcinoma has a 43% risk of getting a second basal cell carcinoma within five years. It is important to have a full body skin examination at least once a year and to do regular self-exams. Be alert to any non-healing sores or lesions that are growing, changing, or bleeding. Since basal cell carcinoma is most frequently caused by the sun’s rays, proper sun protection is important (see section on sunscreens).
Squamous Cell Carcinoma
Squamous cell carcinoma is the second most common type of skin cancer. People with fair complexions and a lot of sun exposure are most commonly affected. Squamous cell carcinoma, while not as serious as malignant melanoma, can metastasize or spread to other parts of the body. It is also locally destructive, so early detection and treatment is important. Squamous cell carcinomas can appear as scaly or crusted flat areas or bumps on the skin often with a red inflamed base, a growing tumor, or a non-healing ulcer. A skin biopsy can confirm the diagnosis. Treatment of choice is dependent upon the location of the tumor, its size, and its microscopic characteristics, and could include surgical excision, electrodessication and curettage (removal by scraping and cauterizing with an electric needle), cryosurgery (freezing with liquid nitrogen), anti-cancer agents, Mohs micrographic surgery and/or radiation therapy.
Squamous cell carcinomas can occur in old burns and chronically traumatized skin. They also are more common in long-standing, immunosuppressed patients (i.e. those who have had transplants).
Sun protection is the best defense against skin cancer caused by UV radiation. Wearing a broad spectrum sunscreen that protects against both UVB and UVA rays is important. Regular self-examinations and being on the alert for any growing, changing, bleeding or non-healing lesions is important. Annual full body skin examinations are recommended especially in patients who have history of skin cancers.
Malignant melanoma is the most serious of all skin the common skin cancers. Melanoma involves the melanocytes, the cells seen in benign moles and the cells that produce pigment causing the skin to tan. Melanoma may appear on previously normal skin or occur within a mole. Almost all melanomas begin on the surface of the skin and can be seen and treated with a very high cure rate when caught early. If the melanoma is given time to grow, it can become invasive and spread throughout the body, resulting in death.
Melanoma can appear as dark black moles with mixed shades of tan, brown, black, red or white with irregular borders. They may even be pink without any pigment. Warning signs of melanoma include any change in a mole such as sensation, color, irregularity or size. Moles being chronically irritated should be removed.
When looking at a spot on the skin it is helpful to apply the ABCDE rules:
A is for asymmetry. One half does not match the other half in size, shape, color, or thickness.
B is for border. The edge or border is irregular. The border can be ragged, notched, scalloped, blurred, or poorly defined.
C is for color. The color or pigmentation is not uniform. Shades of tan, brown, and black are present. Dashes of red, white, and blue add to the mottled appearance. To make detection even more difficult, some melanomas are not even pigmented and may appear as a new flesh-colored or pink area or bump.
D is for diameter. While melanomas are usually greater than 6mm in diameter (the size of a pencil eraser) when diagnosed, they can be smaller. If you notice a new mole different from others, or one that changes in any way, you should see a dermatologist.
E is for evolving. Anything that is changing should arouse suspicion.
Anyone can get melanoma, but some increased risk factors include: fair skin, a history of sunburns, more than 50 moles on your body, atypical moles, or a close relative or family member diagnosed with melanoma.
The best treatment is early detection. Unusual, new or changing lesions can be evaluated by your dermatologist and biopsied to confirm the diagnosis. Treatment for Melanoma is guided largely by the appearance of the melanoma under the microscope. Treatment begins with surgical removal of the entire lesion and some normal skin surrounding the melanoma. Superficial melanomas are almost 100% curable with a simple surgical excision.
Deeper melanomas may require additional procedures or treatments such as, additional surgery, chemotherapy, immunotherapy, or radiation therapy. Early detection remains the best treatment. If you have had a melanoma or have increased risk factors, it recommended that you have more frequent complete skin examinations by your dermatologist.