Skin Cancer

Skin cancer — the abnormal growth of skin cells — most often develops on skin exposed to the sun. But this common form of cancer can also occur in areas of your skin not ordinarily exposed to sunlight.

There are three major types of skin cancer:

• Basal Cell Carcinoma: It begins in the basal cells — a type of cell within the skin that produces new skin cells as old ones die off. Basal cell carcinoma often appears as a slightly transparent bump on the skin, though it can take other forms. Basal cell carcinoma occurs most often on areas of the skin that are exposed to the sun, such as your head and neck.
• Squamous Cell Carcinoma: It is a common form of skin cancer that develops in the squamous cells that make up the middle and outer layers of the skin. Squamous cell carcinoma of the skin is usually not life-threatening, though it can be aggressive. Untreated, squamous cell carcinoma of the skin can grow large or spread to other parts of your body, causing serious complications.
• Melanoma: The most serious type of skin cancer, develops in the cells (melanocytes) that produce melanin — the pigment that gives your skin its colour. Melanoma can also form in your eyes and, rarely inside your body, such as in your nose or throat. The risk of melanoma seems to be increasing in people under 40, especially women.

Other, less common types of skin cancer include:

• Kaposi Sarcoma: This rare form of skin cancer develops in the skin’s blood vessels and causes red or purple patches on the skin or mucous membranes.
  Kaposi sarcoma mainly occurs in people with weakened immune systems, such as people with AIDS, and in people taking medications that suppress their natural immunity, such as people who’ve undergone organ transplants.
• Merkel cell Carcinoma: Merkel cell carcinoma causes firm, shiny nodules that occur on or just beneath the skin and in hair follicles. Merkel cell carcinoma is most often found on the head, neck and trunk.
• Sebaceous Gland Carcinoma: This uncommon and aggressive cancer originates in the oil glands in the skin. Sebaceous gland carcinomas — which usually appear as hard, painless nodules — can develop anywhere, but most occur on the eyelid, where they’re frequently mistaken for other eyelid problems.

• Fair Skin: Anyone, regardless of skin colour, can get skin cancer. However, having less pigment (melanin) in your skin provides less protection from damaging UV radiation.
• A History of Sunburns: Having one or more blistering sunburns as a child or teenager increases your risk of developing skin cancer as an adult. Sunburns in adulthood also are a risk factor.
• Excessive Sun Exposure: Anyone who spends considerable time in the sun may develop skin cancer, especially if the skin isn’t protected by sunscreen or clothing.
• Sunny or High-Altitude Climates: People who live in sunny, warm climates are exposed to more sunlight than people who live in colder climates.
• Moles: People who have many moles or abnormal moles called dysplastic nevi are at increased risk of skin cancer.
• Precancerous Skin Lesions: Having skin lesions known as actinic keratosis can increase your risk of developing skin cancer. These precancerous skin growths typically appear as rough, scaly patches that range in colour from brown to dark pink. They’re most common on the face, head and hands of fair-skinned people whose skin has been sun damaged.
• Family History: If one of your parents or a sibling has had skin cancer, you may have an increased risk of the disease.
• Personal History: If you developed skin cancer once, you’re at risk of developing it again.
• Weakened Immune System: People with weakened immune systems have a greater risk of developing skin cancer.
• Exposure to Radiation: People who received radiation treatment for skin conditions such as eczema and acne may have an increased risk of skin cancer, particularly basal cell carcinoma.
• Exposure to Certain Substances: Exposure to certain substances, such as arsenic, may increase your risk of skin cancer.

Basal cell carcinoma:

Basal cell carcinoma usually occurs in sun-exposed areas of your body, such as your neck or face. It may appear as:

• A pearly or waxy bump
• A flat, flesh-coloured or brown scar-like lesion
• A bleeding or scabbing sore that heals and returns

Squamous cell carcinoma:

Most often, squamous cell carcinoma occurs on sun-exposed areas of your body, such as your face, ears and hands. People with darker skin are more likely to develop squamous cell carcinoma on areas that aren’t often exposed to the sun. It may appear as:

• A firm, red nodule
• A flat lesion with a scaly, crusted surface

Melanoma:

Melanoma can develop anywhere on your body, in otherwise normal skin or in an existing mole that becomes cancerous. Melanoma most often appears on the face or the trunk of affected men. In women, this type of cancer most often develops on the lower legs. In both men and women, melanoma can occur on skin that hasn’t been exposed to the sun.

Melanoma signs include:

• A large brownish spot with darker speckles
• A mole that changes in colour, size or feel or that bleeds
• A small lesion with an irregular border and portions that appear red, pink, white, blue or blue-black
• A painful lesion that itches or burns
• Dark lesions on your palms, soles, fingertips or toes, or on mucous membranes lining your mouth, nose, vagina or anus

To diagnose skin cancer, your doctor may:

• Examine Your Skin. Your doctor may look at your skin to determine whether your skin changes are likely to be skin cancer. Further testing may be needed to confirm that diagnosis.
• Skin Biopsy: Your doctor may remove the suspicious-looking skin for lab testing. A biopsy can determine whether you have skin cancer and, if so, what type of skin cancer you have.

Surgery

• Cryosurgery- Also known as Cryotherapy, this technique uses liquid nitrogen to freeze and destroy the cancer cells. The technique may be repeated several times. The treated area may swell and blister and may be scarred after the wound heals. This is usually only used for small skin cancers or pre-cancerous lesions.
• Excisional Surgery – The surgeon performs an excision with a scalpel or sharp razor, cutting or shaving a growth off the skin. The patient may receive local anaesthesia to numb the affected area. Excisions may leave a scar.
• Mohs Surgery- This technique is designed to remove skin cancer tumours while preserving as much healthy tissue as possible. In this procedure, cancerous cells are removed from the skin layer by layer until the removed layers show no sign of cancer cells. Mohs surgery is most often used on more visible areas, such as the head and neck or hands, to limit scarring. It may also be used on recurrent skin cancers. This surgery may require local anaesthesia and may leave a scar.
• Reconstructive Surgery- Depending on the type of skin cancer and how much skin and tissue around the cancer need to be removed, reconstructive surgery may be recommended to replace the skin and tissue and to minimize scarring.
• Curettage and Electrodessication – In this procedure, a skin lesion is removed with a curette, a long, thin surgical tool with a small, sharp hoop or scoop on the end for scraping. After the lesion is scraped, the area is treated with an electric current through a needle-like electrode designed to kill remaining cancer cells and reduce bleeding. This is called electrodessication. This process of scraping and electrodessication may be repeated several times. It may require a local anaesthetic and may leave a scar.
• Lymph Node Biopsy and Removal – A lymph node biopsy is frequently performed on melanoma patients. In this procedure, your doctor will remove one or more specific lymph nodes, known as sentinel lymph nodes, which directly receive the lymph fluid draining from the tumor. If no sign of cancer is found in the lymph node or nodes, no additional lymph node surgery is necessary. If melanoma cells are found in one or more sentinel lymph nodes, the remaining lymph nodes in the region may be removed.
• Laser Surgery- This technique uses a laser beam, an intense, narrow beam of light, to destroy cancer cells. Laser surgery may be used to treat very superficial skin cancers.
• Surgery for Metastatic Skin Cancer- Basal cell and squamous cell carcinomas, which comprise more than 95 per cent of all skin cancers, usually don’t metastasize. But melanoma, which accounts for about 2 per cent of all skin cancers, may travel to the brain, bones, liver and lungs. When that occurs, surgery may be performed to remove tumours from those locations. Surgery may need to be combined with other treatments, such as immunotherapy or chemotherapy to treat metastatic cancer. In some cases, surgery for metastatic melanoma may be required to relieve symptoms of the disease.

Radiation

• Radiation Therapy – Radiation therapy uses high-powered energy beams, such as X-rays, to kill cancer cells. Radiation therapy may be an option when cancer can’t be completely removed during surgery.

Medical Oncology

• Chemotherapy- In chemotherapy, drugs are used to kill cancer cells. For cancers limited to the top layer of skin, creams or lotions containing anti-cancer agents may be applied directly to the skin. Systemic chemotherapy can be used to treat skin cancers that have spread to other parts of the body.
• Photodynamic Therapy- This treatment destroys skin cancer cells with a combination of laser light and drugs that make cancer cells sensitive to light.
• Immunotherapy- Immunotherapy uses your body’s immune system to kill cancer cells.