What is skin cancer?
Skin cancer is the rapid and uncontrollable growth of skin cells that can occur in different layers of your skin. Skin cancer commonly develops in areas of the skin that has frequent sun exposure like scalp, ears, lips, neck, arms, and hands. But it can also occur on parts of the skin less exposed, like the genital area, the bottom of the feet or palms of the hands.
The Different Types of Skin Cancer
There are three common types of skin cancer associated with the three different types of cells found in the epidermis (top layer of the skin).
- Squamous cells: This type of cell is flat and found in the outer layer of the epidermis. These cells are constantly regenerating. Squamous cell cancer can grow and spread to other layers of the epidermis.
- Basal cells: This type of cell is found in the basal cell layer, which is the lower part of the epidermis. Basal cells divide and form new cells, moving up the epidermis and becoming new flatter squamous cells. Basal cell carcinoma is a very common type of skin cancer and grows slowly on parts of the skin exposed to the sun.
- Melanocytes: These cells make up the skin’s color, called melanin. This layer of cells protects the deeper layer of skin from the sun. Melanoma (caused by a tumor of melanocytes) is not a common type of skin cancer compared to a basal cell or squamous cell cancer but it can be dangerous if not detected or treated early.
Early Detection of Skin Cancer
The ABCDE’s of unusual growths, moles, or spots on the skin can help you detect skin cancer early. A biopsy can determine if a growth is cancerous or non-cancerous.
Asymmetry (A) – if one half of the mole does not match the other.
Border (B) – if the edges are irregular.
Color (C) – if there are different colors present.
Diameter (D) – if the mole is larger than ¼ inch.
Evolution (E) – if the appearance changes over time.
It is recommended to self-check your skin once a month and visit a physician annually. The ABCDE’s can help you decide if you need to speak to your doctor or dermatologist.
Risk Factors and Causes of Skin Cancer
Too much sun exposure is the most common cause of skin cancer, and frequent exposure can significantly increase your risk of developing a type of skin cancer. However, there are other factors as well, including:
Protecting yourself in the sun, applying sunscreen, covering your face and ears, wearing sunglasses, and avoiding UV light are all precautions you can take to limit the risk of skin cancer.
Skin Cancer Treatment for Basal Cell and Squamous Cell Skin Cancer
There are different surgical and non-surgical treatment options to consider to treat basal cell and squamous cell skin cancer.
Local treatments treat the affected area without cutting into the skin.
Here are some different techniques that can be used:
- Cryotherapy – commonly used on pre-cancerous skin conditions. Cryotherapy uses liquid nitrogen to freeze and kill the cells. This type of treatment may be done more than once.
- Photodynamic Therapy (PDT) – similar to cryotherapy, PDT used a gel or liquid to kill any tumor cells. The solution is applied for several hours to make the tumor cells sensitive to light. A special light source is then used to kill the cells.
- Topical Chemotherapy – This treatment uses an anti-cancer drug that is applied directly to the skin over a period of time. This drug cannot reach deeper layers of the skin so; therefore, it is used to treat precancerous skin conditions and basal and squamous cell skin cancer.
- Radiation Therapy – This therapy uses high-powered energy beams, similar to those used in X-rays, to kill cancer cells. This therapy can be considered if surgery alone can not remove the abnormal cells.
Surgical options to treat basal cell and squamous cell skin cancer use surgical instruments to cut into the skin and remove affected areas and, sometimes, the surrounding area.
- Excisional Surgery – This technique can be used to remove most skin cancers, like malignant moles, lesions, and tumors. This involves removing the cancerous tissue and a margin of surrounding healthy skin.
- Mohs Surgery – This procedure may be considered to remove hard to treat skin cancers or a larger affected area. Layers of skin are removed individually and examined until no cancerous cells are present.
- Curettage and Electrodesiccation – This quick procedure used a round shaped blade called a curette to scrape away layers of cancer cells. Electric needles are then used to kill any remaining cancer cells.
Immunotherapy to Treat Melanoma
Immunotherapy uses medicines to stimulate the immune system of the body to detect and destroy cancer cells in the body. It can also be used to slow the growth of abnormal cells.
Melanoma, although not common, is an aggressive type of skin cancer and can spread quickly and can also be fatal if not treated or detected early.
Intensive treatment is considered if the melanoma has spread to the lymph nodes. Treatment can be a combination of different non-surgical and surgical procedures.
How does immunotherapy work?
Immunotherapy uses different drugs to stimulate the immune system to recognize and kill cancer cells. There are several types of immunotherapy that can be used to treat melanoma.
Our immune system uses checkpoints to ensure it does not attack and destroy normal and healthy cells.
Checkpoints are proteins attached to immune cells that need to be activated or deactivated to respond.
The medication used in immunotherapy works to ensure checkpoint proteins are responding correctly and fighting melanoma cells.
Pembrolizumab and nivolumab are drugs that target PD-1, which are T cells that prevent PD-1 immune cells from attacking other cells found in the body.
Blocking PD-1 cells can improve the immune response against melanoma cells, helping to shrink tumors and prolong life.
These drugs are commonly administered through an IV every 2 -3 weeks to treat melanomas that have spread in the body or cannot be removed surgically. They can also be used post-surgery to prevent a recurrence.
Side effects of PD-1 inhibitors include fatigue, nausea, skin rash, itching, constipation, and joint pain.
Ipilimumab is a drug administered to boost the immune response. However, it targets and blocks CTLA-4 proteins on T cells.
It is also given as an intravenous and is also used to treat melanomas that cannot be removed with surgery that has metastasized or to stop cancer from coming back.
There is an increased chance of side effects with this drug and may not shrink tumors as effectively as PD-1 inhibitors. Therefore, it may sometimes be used as a combination.
There are some other types of immunotherapy which show potential in treating melanoma, like the drug Interleukin-2, Bacille Calmette-Guerin vaccine, or imiquimod cream.
In 2018, James. P Allison and Tasuko Honjo were awarded the Nobel Prize in Medicine for discovering new drugs to treat cancer by activating the immune system.
There are different types of skin cancer that can be treated using different techniques and procedures to either stop the growth of abnormal cells or the spread.
Early detection is key to preventing cancer from advancing. Self-checks and annual checks with your doctor are critical, as well as taking the necessary precautions to protect yourself from sun exposure, especially.