Overview and Types
Over one million cases of skin cancer will be diagnosed in the United States this year. Visiting your dermatologist at least annually for a total body skin examination will help you identify skin cancer early, when treatment is often curative. There are several types of skin cancer, each beginning in a specific cell type within the skin. The two most common types of skin cancer are basal cell carcinoma and squamous cell carcinoma, which usually develop on the head, face, neck, hands and arms. These are areas commonly exposed to the sun, but skin cancer can occur anywhere on the body. Another common type of skin cancer is melanoma, a potentially fatal form of skin cancer. Melanoma is now the number one cause of cancer death in people 25-40 years of age.
Basal Cell Carcinoma
Basal cell carcinoma is a slow-growing form of skin cancer that usually occurs on areas of the skin that have been in the sun, most commonly the face. Basal cell cancer rarely spreads to other parts of the body, and is usually treated by surgical excision. When a tumor is large (over 2 cm in diameter on the body), or is located on a cosmetically-sensitive area on the face (such as the eyelid, lip, nose), a special type of treatment called Mohs' Surgery, is indicated. Dr. Andrew Menkes is highly skilled in using Mohs' surgery to treat skin cancer and will help determine the appropriate course of treatment for each patient who is diagnosed with skin cancer.
Squamous Cell Carcinoma
Like basal cell carcinoma, squamous cell skin cancer occurs on parts of the skin that have been in the sun, but can also develop in areas that have been protected from sunlight. It sometimes spreads to lymph nodes and organs inside the body. When detected early, this form of skin cancer is usually completely curable. As with basal cell skin cancers, squamous cell carcinoma is usually treated surgically. Mohs' surgery is performed for skin cancers that are large or those that involve a cosmetically-sensitive area on the face such as the nose, eyelid or lip. Appropriate therapy is determined by our dermatologists after a consultation with the patient to thoroughly discuss each treatment option.
Melanoma is cancer of the pigment cells (melanocytes). The majority of our melanocytes are found in our skin and skin cancer or cutaneous melanoma is the most common form of melanoma. However, ocular or intraocular melanoma can also arise in the melanocytes found in the eye and, more rarely, melanomas can also occur in the lymph nodes, digestive tract, meninges (brain lining) or in other parts of the body where melanocytes also occur.
Melanoma can affect anyone, regardless of age although the chances of getting melanoma increase as we get older. It is one of the most prevalent forms of cancer and can appear on any part of the skin. It generally affects men mostly on the neck, head and body region between the shoulders down to the hips, and in women appears most frequently on the calves.
Black and other dark skinned people rarely develop melanoma but when they do it often appears on the soles of their feet, palms of their hands or under their nails.
Left untreated, melanoma can spread (or metastasize) to other parts of the body. We usually become aware that the melanoma has metastasized when cancer cells are found in the lymph nodes close to the infected body part. One of the roles of the lymphatic system is to filter blood plasma and the lymph nodes act as traps to prevent harmful substances including bacteria and cancer cells from circulating through the body. When cancerous cells are discovered in the lymph nodes it could mean that the melanoma has metastasized to the brain, lungs, liver or other organs. If this occurs, the cancer is known as metastatic melanoma and not brain, lung or liver cancer.
The true causes of melanoma are still a mystery and it is not fully understood why one person develops melanoma while another remains healthy. What we do know, however, is that some people are more at risk than others and that the more risk factors a person has, the more likely he/she is of developing the disease. Having said that, it is not uncommon for people who present NO risk factors to also get melanoma.
People who are concerned about developing melanoma should talk with their doctor about the disease, the symptoms to watch for, and an appropriate schedule for checkups. The doctor's advice will be based on the person's personal and family history, medical history, and other risk factors.
The most common known risk factors for melanoma are:
Abnormal moles (dysplastic nevi):It is more probably that abnormal moles will become cancerous than non-dysplastic nevi, and that the more abnormal moles a patient has, the more likely the development of melanoma. The risk factor is even higher for people with abnormal moles who also have family members with dysplastic nevi and/or melanoma.
Large numbers (50 or more) ordinary moles:Patients who display more than 50 moles are at greater risk of going on to develop melanoma.
Fair skin:Fair skinned, blond or red haired and blue eyed people who easily burn or develop freckles when exposed to the sun are also at higher risk for melanoma than those with darker skins.
Previous history of skin cancer and/or melanoma:Those who have a previous history of melanoma are more likely to go on to develop a second or more melanomas, as are those who have previously had squamous cell or basal cell carcinoma or any other common form of skin cancer.
Family members with melanoma:There is a genetic risk factor for melanoma – in fact about one tenth of people who are treated for melanoma also have a family member with the disease. Those who have two or more close family members who have had melanoma have a higher risk factor. If there appears to be a genetic link, every family member should get a regular check up for melanoma, at least once a year.
Compromised immune system: Anyone who immune system is compromised in any way – by HIV, organ transplant drugs, other cancers or in any other way – are at higher risk for melanoma.
Extreme sunburns that blister: If as a child or teenager you suffered from one or more episodes of severe sunburn that blistered you are more likely to develop melanoma. This is why dermatologists and other doctors regularly recommend that parents be sure to protect young children from the sun with protective sunblock creams, hats and adequate clothing. Severe sunburn as an adult also heightens the risk of melanoma.
UV (ultraviolet) radiation: It is widely thought that one reason for the global increase in melanoma cases is that people are spending longer amounts of time exposed to the sun. Melanoma is far more widespread in places that receive high levels of UV radiation, such as Texas, than in latitudes where the sun is less fierce. It has been well documented that excessive levels of UV lead to premature skin aging and skin damage which are often the precursors to melanoma. In addition, sunning booths, sun lamps and other artificial sources of UV also increase the risk factors for melanoma and are best avoided.
- If possible, lessen your exposure to UV and in particular keep out of the sun between the hours of 10 a.m. to 4 p.m.
- Wear a wide brimmed hat and long sleeves and pants when you go outside.
- Remember that water, sand, snow and ice reflect UV light and this is equally damaging to skin.
- Always use sun block in the form of lotions, creams or gels with a minimum Sun Protection Factor (SPF) or 15 or more. The higher the number, the better the degree of protection against UV light.
- Always use sunglasses when out in the sun and make sure they have UV-absorbing lenses that stop at least 99% or UVA and UVB rays from reaching your eyes and the delicate skin that surrounds them.