What is Melanoma?
Melanoma or skin cancer is a malignant disease of the skin. The cancerous tumors appear in the melanocytes, cells that are responsible for the darker color in the skin. It is especially common in Caucasian individuals who live in very sunny climates.
Causes of Melanoma
Skin cancer occurs when melanin making skin cells grow out of control forming a large mass of irregular cancer cells. This abnormal growth is due to damage to the DNA of the skin cells. While there is no absolute surety as to what causes the damage it is believe that excess exposure to UV light that comes from tanning beds and the sun is the probable leading cause.
Medications for Skin Cancer
The drug dicarbazine or DTIC is the chemotherapeutic agent used to treat metastatic melanoma. Interferon is used to weaken skin cancer cells. To assist in the side effects of chemotherapy Aprepitant or Emend is used in conjunction with dexamethasone and ondansetron. Dramamine (dimenydrinate) and Reglan (metoclopramide) are used to treat the nausea. Temodar(temozolomide) is used to treat melanoma that has mestastisized to the brain.
Prevention of Skin Cancer
The best way to prevent skin cancer is to avoid all sources of ultraviolet radiation. Of course that would mean staying out of the sun completely. As an alternative cover skin when out in the sun buy wearing a hat with a broad brim, long pants and long sleeved shirts. Whether sunscreen protection using high SPF lotions prevents melanoma is still a subject for debate. However it is advisable to avoid tanning beds that emit UVA light. Try to avoid being out in the sun from 9am to 3pm when the sun is at its strongest.
Risk Factors of Melanoma
There are several different factors that predispose an individual to skin cancer:
- Fair appearance-People with very light skin have less protection from the UV rays of the sun. Those who have light or red hair, blue eyes and tend to sunburn easy are at higher risk for melanoma.
- Sunburn-Getting a severe sunburn that blistered during childhood increases risk of developing melanoma later in life.
- UV light exposure-Individuals who spend a lot of time tanning in the sun or using a tanning bed may be more predisposed to melanoma.
- Living near the equator or at high elevations-People who live where the rays of the sun are stronger are exposed to more UV light. This can lead to melanoma.
- Lots of moles-Those who have 50 moles or more on their body have a greater likelihood of developing melanoma. In addition those with atypical moles called dysplastic nevi are more prone to melanoma.
- Family history of skin cancer-Individuals with relatives that have melanoma are more likely to develop it themselves.
- Compromised immune system-Immunosupressed individuals such as those who are HIV positive are more likely to develop skin cancer.
Symptoms of Melanoma
The first sign of skin cancer is a mole that has changed its shape or its color. In nodular melanoma the first indication is a lump on the surface of the skin. During later stages of the disease the mole may ulcerate, bleed or itch. Melanoma lesions usually appear with irregular borders and varying shades of colors. Their initial diameter is usually the size of a pencil eraser and they will grow and spread out as time goes on.
Treatment for Skin Cancer
The best way to treat a melanoma is with complete excision of the lesion. If the melanoma has spread to the lymph nodes it is tested for cancer cells. If cells are found the lymph nodes will be removed and additional treatment required. After resection of the lymph nodes the patient will undergo treatment using interferon. Chemotherapy medications may also be used. For those suffering from Lentigo maligna excision is the first step to cure the patient. The option of following up with a topical cream that serves to enhance the immune system may be initiated at this point. Radiation treatments are also used to prevent recurrence where the melanoma was removed. Vaccines, gene therapy and experimental drugs are all currently being investigated.
Types of Melanoma
There are four basic types of melanoma:
- Superficial Spreading Melanoma-This melanoma counts for 70% of all cases. It can strike at any age in either males or females and is the leading form of cancer causing deaths in younger people. It first appears as a freckle and will later darken and develop irregular edges.
- Nodular Melanoma-This type of melanoma appears in approximately 15% of the cases. It is quite aggressive and is seen in older people. These lesions tend to get thicker rather than spread out. This type of melanoma is not easy to see in its initial phase of development. In addition it does not develop from a mole but can grow anywhere on the skin.
- Lentigo Maligna Melanoma-Skin cancer of this type is most common on skin that has been regularly exposed to the sun. It may initially be mistaken for an age spot. It counts for 10% of all diagnosed cases. The lesion is flat in varying shades of brown and has jagged borders. Over a time period of 15 years the lesion grows very slowly. It changes color to a dark black or brown as it grows deep into the skin. Nodules can appear within the lesion. These nodules are the actual tumor.
- Acral Lentiginous Melanoma-Approximately 5% of diagnosed cases are this type of melanoma. The lesions can occur anywhere on the body and usually in areas that are not commonly examined. The lesions may appear on the soles of the feet, under fingernails or in mucous membranes like the nose or mouth.
There are also some atypical subtypes of skin cancer. Amelanotic melanoma manifests as a red or pink lump. Desmoplastic neutrotrophic melanoma resembles a scar and appears mostly on the neck or head of elderly people.