The occurrence of skin cancer is highest among the types of cancer that are faced in the country. Almost 50% of Americans are likely to develop some form of skin cancer before the age of 65. Though specific causes are not known, it is suspected that the cause of skin cancer is genetic.

Most cases of skin cancer occurrences are attributed to exposure to ultraviolet (UV) light present in sunlight and tanning beds. However, some cases of skin cancer have been known to develop in areas rarely exposed to the sun like the fingernail bed or genital area.

The most common skin cancers are basal cell carcinoma and squamous cell carcinoma. Both these cell types are found in the bottom and top layers of the skin respectively. Skin cancer appears in different forms. In the case of the basal cell, it appears as a scar-like, flesh-colored or brown lesion. In squamous cell carcinoma, a flat lesion or nodule appears with a crusted, scaly surface. A third, less common type of skin cancer called melanoma can occur even in areas that are not exposed to UV light. Melanoma appears in the form of a mole or as brown spots.

Diagnosis
The commonly used tests to diagnose skin cancers are skin examinations, biopsies, and imaging tests. Skin examinations look at lesions and tumors present on the skin. In some cases, the outer appearance is enough to diagnose skin cancer.

Biopsies are done by taking out samples of the tumor or lesion. There are different types of biopsies. An excision biopsy cuts out the entire growth, lesion or tumor. This is sometimes sufficient treatment in itself. A shave biopsy is done by shaving off the top layers of the tumor and the specimen is subject to tests to determine the presence of cancerous cells. A punch biopsy uses a special cylindrical tool to punch a hole in the tumor and remove a round piece along with the inner layers of the skin. In cases of malignant melanoma, further tests will be done to determine the extent of the spread of the disease. These involve chest x-rays and blood tests. Other biopsies like surgical lymph node biopsy, sentinel lymph node biopsy, and fine-needle aspiration biopsy may also be done.

Imaging tests including CT scans, MRI scans, PET scans, bone scans, and chest x-rays are done to look for metastasis or if cancer has spread to other organs.

Treatment

• Surgery: Excisional, Mohs, and electrodesiccation are different methods of surgery used to treat cancer. Excisional surgery removes the entire tumor and a little bit of the surrounding tissue while Mohs surgery involves removing the skin growth layer by layer. This procedure is used for basal cell carcinomas and squamous cell carcinomas that are difficult to treat or are recurring. Cryotherapy is done by first removing most of the growth and then using a curette (a circular blade) to remove the remaining cancerous cells. Sometimes liquid nitrogen is used to freeze the edges and base of the treatment area.
• Radiation therapy: High-powered X-ray beams are focused on the cancerous area to kill cancer cells. This method may be used where surgery could not remove the tumor entirely.
• Chemotherapy: In this, drugs are used to kill cancer cells. In case the tumor is on the skin, topical creams and lotions containing anti-cancer drugs are applied. Metastasized cancers require systemic chemotherapy.
• Freezing or Cryotherapy: Liquid nitrogen is applied to freeze small pre-cancers like actinic keratosis and other skin cancers at an early stage.
• Photodynamic therapy: A combination of medications that make cancer cells sensitive to light and laser light is used to kill cancer cells.
• Biological therapy: Drugs that bolster the body’s immune system to fight cancerous cells are used to eventually kill cancer cells.