How Is Skin Cancer Diagnosed?
Skin cancer is divided into two major groups: non-melanoma and melanoma. Non-melanoma includes basal cell carcinoma and squamous cell carcinoma. Customized treatment is required for each type of skin cancer.
Melanoma and other forms of skin cancer are diagnosed by a skin biopsy that removes all or part of the growth. A sentinal lymph node biopsy may be done in some people with melanoma to ensure that the cancer has not spread to nearby lymph nodes.
Once melanoma has been diagnosed, CT scans or other types of imaging tests may be ordered by your oncologist to determine whether the cancer has spread.
Melanoma is caused by changes in cells called melanocytes, which produce melanin, a skin pigment responsible for skin and hair color. Melanoma can appear on normal skin, or it may begin as a mole or other area that changes in appearance. Some moles present at birth may develop into melanomas.
There are 4 major types of melanoma:
- Superficial spreading melanomais the most common. Flat and irregular in shape and color, with different shades of black and brown, it is most common in Caucasians.
- Nodular melanomausually starts as a dark blackish-blue or bluish-red raised area; some have no color.
- Lentigo maligna melanomausually occurs in older adults. Most common in sun-damaged skin on the face, neck and arms, this type of melanoma is usually large, flat and tan with areas of brown.
- Acral lentiginous melanoma, the least common form, usually occurs on the palms, soles or under the nails and is more common in African Americans.
Basal Cell Carcinoma
Basal cell carcinoma is a type of non-melanoma skin cancer, and is the most common form of cancer in the United States. According to the American Cancer Society, 75% of all skin cancers are basal cell carcinomas.
Squamous Cell Carcinoma
Squamous cell carcinoma may occur in normal skin or in skin that has been injured or inflamed. Although it usually occurs on the face, ears, neck, hands or arm, it may occur on other areas.
Treatment of Melanoma
Melanoma is the most dangerous type of skin cancer and the leading cause of death from skin disease.
Surgery and Other Treatments
Surgery is necessary to treat melanoma. The cancer itself and some surrounding tissue will be removed. The amount of skin removed depends on how deep the melanoma has grown. If the cancer has spread to nearby lymph nodes, the lymph nodes may also be removed.
Treatment is more difficult when the melanoma has spread to other organs. You may receive:
- Chemotherapy to kill the cancer cells
- Immunotherapy, such as interferon or interleukin, to help your immune system fight the cancer
- Radiation therapy to relieve pain or discomfort
If you have melanoma that is hard to treat, you might consider enrolling in a clinical trial. Researchers continue to study new treatments. Ask your doctor for more information.
Treatment of Basal Cell Carcinoma and Squamous Cell Carcinoma
Treatment varies depending on the size, depth and location of the basal cell cancer. Your dermatologist will remove it using one of the following procedures:
- Excision to remove the tumor
- Curettage and electrodessication to scrape away the cancer and kill any remaining cancer cells
- Surgery, including Mohs or Johns surgery, in which skin is cut out and immediately examined under a microscope to check for cancer. The process is repeated until the skin sample is free of cancer.
- Cryosurgery to freeze and kill the cancer cells
- Radiation if the cancer has spread to organs or lymph nodes or for tumors that can't be treated with surgery
- Skin creams with the medications imiquimod or 5-fluorouracil to treat superficial basal cell carcinoma
- Photodynamic therapy, or treatment using light, may be used for Bowen's disease.
Radiation therapy may be used for squamous cell skin cancer that has spread to organs or lymph nodes, or when it cannot be treated with surgery.