context: All potentially cancerous skin growths must be biopsied to confirm a cancer diagnosis. Depending on the suspected type of skin cancer, the biopsy techniques vary slightly but crucially. Any potential melanoma requires a surgical biopsy, in which the entire growth is removed with a scalpel if possible. A pathologist then studies the sample under a microscope to determine whether cancer cells are present. Ifmelanomais diagnosed, other tests may be ordered to assess the degree of cancer spread (metastasis). They include: Imaging. Your doctor will order one or more tests to look for metastasis. They include CT scan, MRI, PET scan, bone scan, and chest X-ray. Other biopsies. Using a variety of techniques, your doctor may want to get tissue samples from lymph nodes. Skin growths that are most likely basal cell carcinoma, squamous cell carcinoma, or other forms of non-melanoma can be biopsied in various ways. Part or all of the growth can be taken with a scalpel for examination under a microscope. Most skin cancers are detected and cured before they spread. Melanoma that has spread to other organs presents the greatest treatment challenge. Standard treatments for localized basal cell and squamous cell carcinomas are safe and effective and cause few side effects. Small tumors can be surgically excised, removed with skin scraping and electric current cauterization, frozen with liquid nitrogen, or killed with low-dose radiation. In rare cases where basal cell or squamous cell carcinoma has begun to spread beyond the local skin site, the primary tumors are first removed surgically. Then patients may be treated with radiation, immunotherapy in the form of interferon, and rarely, chemotherapy. However, responses to this therapy are infrequent and short-lived. Rare patients with advanced squamous cell carcinoma respond well to a combination of retinoic acid (a derivative of vitamin A) and interferon (a type of disease-fighting protein produced in labs for cancer immunotherapy). Retinoic acid may inhibit cancer recurrence in patients who have had tumors removed, but there is a lack of evidence to support either of these treatments. Vismodegib ( Erivedge) may be used to treat the rare cases of locally advanced, or metastatic, basal cell carcinoma and has been shown to shrink these tumors. Sonidegib ( Odomzo) can be used to treat patients with locally advanced basal cell carcinoma who are not candidates for surgery or radiation. It may also be used if the skin cancer returns after surgery or radiation. Melanoma tumors must be removed surgically, preferably before they spread beyond the skin into other organs. The surgeon removes the tumor fully, along with a safe margin of surrounding tissue and possibly nearby lymph nodes. Neither radiation nor chemotherapy will cure advanced melanoma, but either treatment may slow the disease and relieve symptoms. Chemotherapy, sometimes in combination with immunotherapy -- such as interferon, interleukin-2 -- is generally preferred. If melanoma spreads to the brain, radiation is used to slow the growth and control symptoms. Proton therapy may be used, as well. Immunotherapy is a field of cancer treatment that attempts to target and kill cancer cells by manipulating the body's immune system. Some of the most promising developments in the field of immunotherapy have arisen from efforts to cure advanced melanoma. Some researchers are treating advanced cases with vaccines, while others are using drugs such as interferon, interleukin-2, and ipilimumab ( Yervoy) in an effort to stimulate immune cells into attacking melanoma cells more aggressively. In patients with advanced melanoma, two drugs, nivolumab ( Opdivo) and pembrolizumab ( Keytruda) have been found to be effective after use of ipilimumab. These drugs help block proteins on T cells that normally help keep them in check, therefore allowing these immune cells to attack melanoma cells. Genetic manipulation of melanoma tumors may make them more vulnerable to attack by the immune system. Each of these treatment approaches aims to immunize a patient's body against its own cancer -- something the body cannot do naturally. There are other drugs that target specific genes within normal cells that cause them to become cancerous. Called targeted therapy, these drugs include dabrafenib ( Tafinlar), trametinib ( Mekinist) and vemurafenib ( Zelboraf). People who have had skin cancer once are at risk for getting it again. Anyone who has been treated for skin cancer of any kind should have a checkup at least twice a year. About 20% of skin cancer patients experience recurrence or a second separate tumor, often within the first two years after diagnosis. Once skin cancer is diagnosed, the only acceptable treatment is medical care. Alternative approaches may be useful in cancer prevention and in combating nausea, vomiting, fatigue, and headaches from chemotherapy, radiation, or immunotherapy used to treat advanced skin cancer. Be sure to discuss any alternative treatments you are considering using with your cancer doctor. Skin experts know that the mineral zinc and the antioxidant vitamins A (beta-carotene), C, and E can help repair damaged body tissue and promote healthy skin. Now, researchers are trying to determine whether these and other nutrients might protect skin from the harmful effects of sunlight. To test the theory, selected skin cancer patients are given experimental supplements of these vitamins in the hope of preventing cancer recurrence. Thus far, no nutrient has been found to be protective against skin cancer.