Skin cancers are the most common cancers, and treatment is beneficial.
Anatomical facts: The skin is the largest organ in the body. Its main function is to cover and protect the internal organs against heat, sunlight, injury, and infection. Other functions are to regulate the body’s temperature, store water and fat, and produce vitamin D. The skin has two main layers: the epidermis and dermis. The outer layer, the epidermis, is made of three types of cells: squamous cells, basal cells, and melanocytes. The dermis, which lies underneath the epidermis, contains blood vessels, lymph vessels, hair follicles, nerves and sweat glands. Skin cancer is the most common type of cancer in the United States.
The American Cancer Society does not provide an annual projection of skin cancer diagnoses because most non-melanoma cases are not reported. It is estimated that 40% to 50% of Americans are diagnosed with non-melanoma skin cancer by the time they reach age 65. Fortunately, the majority of cancers that develop in the skin are either basal cell carcinoma or squamous cell carcinoma. Both of these cancers are usually diagnosed in the early stages and are highly curable. Although it is very common, only I,000-2,000 deaths per year are attributed to non-melanoma skin cancer, and most deaths occur when people do not receive treatment soon enough or when a person has a suppressed immune system.
Causes of skin cancer:
The cause for both basal cell carcinoma and squamous cell carcinoma is exposure to ultraviolet (UV) radiation from the sun or artificial sources such as sunlamps and tanning booths. Occurrence of skin cancer is correlated to the level of UV exposure in a lifetime, resulting in a higher incidence among people who live in areas that get high levels of UV radiation and people over the age of 50.
Most non-melanoma skin cancers can be completely cured by a fairly minor surgical procedure performed in the physician’s office as outpatient surgery. One of these procedures, Mobs surgery, can be performed only by physicians who have had special training. This is a multistep procedure that consists of removing a thin layer of growth and examining it under the
microscope before moving on to the next one. The goal of this surgery is to remove only cancerous tissue, with a very small margin of healthy tissue. With this method, it is possible to achieve a better cosmetic result. This is an important advantage, especially when treating tumors on the face.
Treatment of skin cancer:
Treatment for skin cancer depends on several factors like the size, type, depth and location of the lesions. Some treatments that are currently in use are standard while others are being tested in clinical trials. Most skin cancers are detected and cured before they spread.
Melanoma that has spread to other organs presents the greatest treatment challenge. Malignant melanoma is a highly aggressive cancer that tends to spread to other parts of the body. These cancers may be fatal if not treated early.
The non-melanoma skin cancer types are basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) which can be treated easily. Actinic keratosis, a pre-malignant condition of skin can also be easily treated.
Treatment options that may be used are:
- Radiation therapy
- Photodynamic therapy
- Biological therapy
Surgery is the mainstay treatment for all kinds of skin cancer. It is effective for the non-melanoma types which have not spread while additional treatment may be required for melanoma skin cancer. Different surgical procedures can be used. These are the following:
Excision of the cancer: For the non-melanoma types which are limited to the surface of the skin, simple surgical excision is good enough. It is essential to excise melanoma tumors before they start spreading to other organs. A wide excision may be recommended in some cases. A wide excision involves removal of the cancerous region and a margin of healthy tissue to ensure complete removal of cancer cells.
Curettage plus electrocautery: Small skin cancers can be treated by this procedure.It involves scrapping away the cancerous part with a curette (spoon like instrument). The treatment is done under local anaesthesia. To ensure that the cancer has been entirely removed, additional treatment in done. A needle through which electric current is passed is then used to kill remaining cancer cells and stop bleeding.
Cryotherapy: It involves the use of liquid nitrogen to freeze and kill the cells in the cancerous part of the skin.
Laser destruction: It involves killing of the cancer cells with the help of high energy laser beam.
Mohs micrographic surgery: It is a distinctive kind of surgery named after Dr. Frederick Mohs.It is also known as margin controlled excision.Skin cancers, which gave grown at sensitive areas, which are rare, which large and aggressive or which come back after treatment, can be treated with the help of this surgical procedure. The cancer is removed slowly little by little. As each part of the skin is removed, it is observed under the microscope for signs of cancer. The procedure ensures complete removal of cancer cells and minimum removal of healthy tissue.A reconstructive surgery may be required if a lot of tissue is removed.
Dermabrasion: It is a procedure of removing the top layer of skin with the help of a rotating wheel or small particles to rub away skin cells.
Lymphadenectomy: It involves removal of lymph nodes near the cancer affected region of the skin, especially when there is evidence of spread of the cancer. This surgery is usually done for treatment of squamous cell cancer, which may spread to lymph nodes. Basal cell cancer rarely spreads to lymph nodes.
Skin grafts and skin flaps: These are skin layers which are removed from other healthy regions of the patient’s body to graft over the area removed by excision. Skin flaps are thicker layers while skin grafts are thin layers of skin.
Chemotherapy refers to the use of drugs to kill cancer cells. When drugs are administered through a vein or by mouth, then this kind of chemotherapy is called systemic chemotherapy. This form of chemotherapy is used when cancer has spread throughout the body and surgery is not possible. Direct administration of the chemotherapeutic agent to the target organ is called regional chemotherapy. The side effects depend on the kind of drugs used and their dose.
Non-melanoma skin cancer and actinic keratoses can be treated with lotions. These lotions contain anti-cancer drugs like 5-fluorouracil (5-FU), Efudex and Fluoroplex. Vitamin A (Retinoids) may also be administered orally for treating non-melanoma skin cancer and squamous cell carcinoma.
Chemotherapy will not cure advanced melanoma,but may slow the disease and relieve symptoms. Chemotherapy, sometimes in combination with immunotherapy — using drugs like interferon — is generally preferred.
Radiation therapy refers to the use of high energy X rays to kill cancer cells. It is a local therapy since it is directed to the affected site.
Radiation can be given either externally or internally.
External radiation therapy: A beam of radiation from a machine outside the body is aimed at the affected site of the patient’s body.
Internal radiation therapy or brachytherapy: Radioactive substance sealed in small pellets is placed near the affected region. Cancer cells are killed by the radiations emitted from the radioactive substances.
Radiation therapy is not usually used as the main treatment for skin cancer. It may be used for basal and squamous cell cancers when surgery is not possible, or when cancer has spread to other organs and lymph nodes. It may also be used when the cancer has spread over a wide region. It cannot cure advanced stage melanoma which has spread to other organs. Radiation is mainly used to slow down the progression of the skin cancer and relieve symptoms.
Photodynamic therapy (PDT) is a new form of cancer treatment which makes use of a light sensitive drug and a certain type of laser light. The drug after administration accumulates more in the tumor cells than normal cells. It is then activated by a special type of laser light which is focused on the skin. The active drug then kills the cancer cells. This treatment has minimum side effects. The patient needs to avoid direct sunlight for a long time after this treatment.
Biological treatments work by activating the immune system to fight against cancer. Imiquimod (Aldara) is a biological therapy drug. It activates the cells through toll-like receptor 7 (TLR7), which causes the activated immune cells to secrete interferons and cytokines which can kill the cancer cells. The medicine is applied on the skin for several weeks to treat a superficial tumor. A new form of therapy involves the use of a drug called vemurafenib. It is a B-Raf protein inhibitor and can be used to treat advanced stage or malignant melanoma with an abnormal BRAF gene.
Although most non-melanoma skin cancers can be completely cured, survivors need to perform skin self-exams and be monitored very closely by a physician. People with a history of skin cancer must become knowledgeable about preventing UV exposure and about special products and clothing that protect from the sun.
Clinical trials refer to those kinds of treatment which are not yet standardized. It is a part of research that aims to develop better strategies for the treatment of cancer. The patients may willingly participate in clinical trials and help researchers formulate new kinds of treatment.
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This article was originally published on 7/12/2014 and last revision and update of it was 9/14/2015.