Skin Cancer

1 What is Skin Cancer?

Skin cancer is a type of cancer that affects skin cells and causes them to grow and multiply in an uncontrolled manner.

Most of the skin cancers occur in the part of the skin that is exposed to the sun. However, skin cancer may develop in those parts which have minimum sunlight exposure.

skin cancer

The most common skin cancers are basal cell carcinoma, squamous cell carcinoma and melanoma. Limited exposure to UV radiation can significantly reduce your risk of developing skin cancer.

Skin cancer is more likely to be cured if detected at early stage. Schedule a routine skin check-up so that any abnormal changes in the skin can be immediately noticed.

As with any cancer, early detection often results in better outcomes.

2 Symptoms

Signs and symptoms of skin cancer vary depending on its type.

Most of the skin cancer occurs in those parts that are frequently exposed to sunlight, such as scalp, face, lips, ears, neck, chest, arms and hand, and legs in female.

However, skin cancer can also develop in the parts, such as palms, beneath the fingernails or toenails, and genital area that is less frequently exposed to sunlight.

Skin cancer affects people of all complexions. People with dark complexion develop are likely to develop melanoma in parts that have limited or rare sunlight exposure, such as the palms of the hands and soles of the feet.

Basal cell carcinoma occurs mostly in those areas where sunlight exposure is high. It is likely to develop in neck or face.

Its signs and symptoms are:

  • Slightly raised skin that appears shiny
  • A flat, flesh-colored or brown scar-like lesion

Squamous cell carcinoma develops in the part of the skin that is exposed to the sun-like face, ears, and hands.

Squamous cell carcinoma, in people with a darker complexion, often develops in the part of skin where sunlight exposure is rare.

Signs and symptoms of squamous cell carcinoma may include:

  • A hard, red bump on the affected part
  • A smooth lesion with flaky and crusted surface

Melanoma can form in any part of your skin, be it a normal skin or an existing mole. In a male, melanoma commonly affects face or the trunk while in female lower legs are affected.

Melanoma, in both sexes, may occur in those parts where sunlight exposure is rare. Development of melanoma in people is independent of their skin complexion.

Following are the signs and symptoms of melanoma:

  • A large brownish freckle
  • A mole that changes in color, size, and texture or a mole that bleeds
  • Small red, white blue or blue-black lesion with irregular edges
  • Dark lesions on your palms, soles, fingertips or toes, or on mucous membranes lining your mouth, nose, vagina or anus

The cancers that occur less commonly are:

Kaposi sarcoma: It occurs in blood vessels in the skin. Red or purple patches are seen in skin or mucus membranes.

Immunocompromised people, such as people with AIDS, and people taking immunosuppressant, such as people who have had an organ transplant, are likely to develop Kaposi sarcoma.

Older men of Italian or Eastern European Jewish heritage or younger men of Africa have high chances of developing Kaposi sarcoma.

Merkel cell carcinoma: Merkel cell carcinoma develops on or just below the skin and in hair follicles. 

It mostly appears on head, neck and trunk. The firm, shiny nodules are seen in Merkel cell carcinoma.

Sebaceous gland carcinoma: It is a cancer of oil glands of the skin occurring mostly on the eyelid. However, it can develop on any part of the skin.  

The firm, painless nodules are seen in sebaceous gland carcinoma.
Visit your doctor if you observe any suspicious changes in your skin.

3 Causes

Skin cancer is caused by abnormalities in the DNA of skin cells (DNA mutations). DNA mutations result in an abnormal and “out-of-control” growth of cells.

Different types of cells are present in the skin which can develop skin cancer. Skin cancer originates in the epidermis, the outermost thin and protective layer of skin.

Epidermis is composed of three different types of cells: squamous cells, basal cells, and melanocytes. Squamous cells are situated below the outermost covering of skin.

Basal cells lie just below the squamous cells and continuously generate new skin cells. The lower part of the epidermis is occupied by melanocytes, the cells that produce a pigment which gives skin its color.

Melanin production is increased when your skin is exposed to sunlight. Your treatment choice for skin cancer as well as its type is dependent upon its origin.

Mutation of DNA in skin cells are mostly caused by ultraviolet (UV) radiation present in sunlight and in the lights used in tanning beds.However, skin cancers can occur in areas that are not exposed to sunlight.

Other factors such as exposure to toxic substances or weakened immune system may increase the risk of developing skin cancer.

4 Making a Diagnosis

Making a diagnosis of skin cancer is done by performing several tests.

If you notice any suspicious changes in skin, see your doctor immediately. Your primary care doctor, if suspects that you have developed skin cancer, may refer you to a dermatologist (a specialist in skin diseases).

Getting prepared for the visit can optimize the therapy and help make the visit more fruitful. List out all the symptoms. Write down your key medical information.

Write down the names of all your medications, vitamins or supplements. Ask a friend or a family member to accompany you for the visit. Make a list of the questions to ask your doctor.

Some typical questions can be:

  • Do my symptoms indicate skin cancer?
  • If yes, what type?
  • Do I need more tests?
  • What are my treatment options and potential risks of each treatment?
  • Is there a risk of the scar after surgery?
  • What’s the possibility of additional skin cancers?
  • How can I prevent additional skin cancers?
  • Do I need to be checked periodically for additional skin cancers?
  • Should I see a specialist?
  • Do I need to come again for a follow-up visit?

A clear talk with your doctor can optimize the therapy and improve the outcomes. Prepare yourself to answer some essential questions from your doctor.

Your doctor might ask you typical questions like:

  • When did you start noticing your skin changes?
  • Has your skin lesion grown or changed?
  • Have you noticed any skin lesion that bleeds or itches?
  • How severe are your symptoms?

You doctor is likely to do following tests for diagnosis of skin cancer:

Examination of your skin: Your doctor will check your skin to detect whether there are any signs of skin cancer. To determine whether you have skin cancer some other tests may be required.

Skin biopsy: A sample of skin is obtained for laboratory analysis. Skin biopsy not only determines whether you have skin cancer but also the type of skin cancer.
Once your doctor confirms the diagnosis, s/he may recommend further tests to determine the extent of your skin cancer.

A biopsy in which the sample contains an entire abnormal area of growth is sufficient to determine cancer stage.

Additional tests may be required if you have large squamous cell carcinoma, Merkel cell carcinoma or melanoma.

Additional tests might include:

  • Imaging tests to scan the neighboring lymph nodes to detect the signs of cancer
  • Sentinel lymph node biopsy: In this type of biopsy, the sample of tissues from the nearby lymph nodes is removed for laboratory analysis.

Roman numerals I to IV are used to indicate cancer's stage. Stage I cancers are confined to the site of their origin whereas Stage IV indicates advanced cancer that has spread distant body parts.

Stage of skin cancer helps to choose treatment options best suited to your condition.

5 Treatment

The selection of your treatments for skin cancer and actinic keratoses (skin lesions that can develop into cancer) relies on the size, type, depth and location of the lesions.

Skin cancer confined to the certain area of skin may not require other treatments after complete removal of growth of abnormal cells by skin biopsy.

Other treatment options, if required, could be:

  • Cryosurgery: In simple terms, it means freezing precancerous lesions (actinic keratoses) and initial skin cancers to death by using liquid nitrogen.
  • Excisional surgery: The cancerous tissue and healthy skin near the cancer are surgically removed. In few cases, additional removal of healthy tissue near the cancerous tissue (wide excision) may be done. This surgical treatment can perform for almost all type of skin cancer.
  • Mohs surgery: This treatment is reserved for cases of basal and squamous cell carcinomas where skin cancers are larger, recurring or difficult to treat. This surgery is performed in few cases where it is essential to preserve maximum skin such as, in a case of the nose. In this procedure, each layer of skin growth is examined for cancer until it is confirmed that there are no cancerous cells left behind. The confirmation is done by viewing cells of each layer under the microscope.
  • Curettage and electrodesiccation or cryotherapy: After most of the layer of skin growth have been removed, the remaining layers of a tumor are cut out with the help of the device that contains a circular blade (curet). If any cancer cells are left behind, an electric needle is used to destroy them. The remaining cancer cells can also be frozen by using liquid nitrogen. Basal cell and squamous cell cancers are mostly treated by this process.
  • Radiation therapy: It uses ionizing radiations like X-rays to destroy cancer cells. It is usually the treatment of choice when removal of the entire cancer is not possible through surgery.
  • Chemotherapy: Chemotherapy uses drugs to kill cancer cells. If cancers are confined to the superficial layer of skin, anti-cancer drugs in the form of creams or lotions can be applied directly to the skin. If cancer has spread to other parts of the body, oral or intravenous (injected into a vein) chemotherapy may be given.
  • Photodynamic therapy: In this therapy, the cancer cells are first sensitized to light by certain drugs and a laser is used to destroy them.
  • Biological therapy: Biological therapy activates your body's immune system against the cancer cells.

6 Prevention

Skin cancer is a common but very preventable type of cancer.

Following measures can be useful to protect yourself from skin cancer:

  • Avoid the sun when its rays are strongest: Avoiding the sun for a certain duration in a day decreases the incidence of sunburns and suntans thereby decreasing the risk of skin cancer. The rays are strongest from 10 a.m. to 4 p.m. Try to avoid outdoor activities during the middle of the day, even if it's winter or cloudy. Remember that clouds do not shield UV radiations. Prolonged exposure of skin to the sun can cause skin cancer.
  • Use sunscreen: Apply sunscreen on the body parts most likely to be exposed to the sun. Sunscreens don’t protect from all harmful UV radiation, especially the one that can cause melanoma, but give sun protection. Use a sunscreen that has SPF of 15 or higher. Apply it generously every two hours. You may need to reapply if you are swimming or sweating.
  • Wear clothes that shield harmful radiations: Since sunscreen can't completely protect you from UV rays, it is important to cover your skin with protective clothing.
  • Use sunglasses that block both UVA and UVB rays.
  • Avoid tanning beds: Since the lights used in tanning beds emit UV rays, it is better to avoid tanning bed unless very necessary.
  • Some OTC or prescription medications may increase your skin’s sensitivity to sunlight. Ask your doctor or pharmacist if the medications you are using cause photosensitivity. 
  • Frequent examination of your skin may help early detection of your skin changes. 
  • Seek medical advice if you observe any abnormal changes such as skin growths or changes in bumps, birthmarks, moles or freckles.

7 Risks and Complications

There are several risks associated with skin cancer, which include:

  • Fair skin: Although anyone can develop skin cancer, your risk increases if you have fair skin. This is due to the fact that melanin, which protects from UV radiation, is less in fair skin.
  • You may be at a higher risk if you have blond or red hair, light-colored eyes and get sunburn easily.
  • A history of sunburns: Sunburns during childhood or teenage are associated with greater risk of skin cancer later in life.
  • Excessive sun exposure: Prolonged exposure of unprotected skin to the sun increases the chances of having skin cancer.
  • Sunny or high-altitude climates: People living in temperate climate have high exposure to sunlight than the people living in colder climates.
  • Moles: You are more likely to get skin cancer if you have dysplastic nevi (abnormal moles which are larger than normal ones). Dysplastic nevi have a high possibility of developing into cancer than other moles.
  • Precancerous skin lesions: The chances of having skin cancer increases if you have actinic keratoses (skin lesions which are scaly). Actinic keratoses mostly occur on the face, head and hands.
  • A family history of skin cancer: If anyone from your family suffered from skin cancer, you pose a high risk of getting the same disease.
  • A personal history of skin cancer: Chances of recurrence of skin cancer is high if you already developed skin cancer once.
  • A weakened immune system: Immunocompromised people, such as those suffering from AIDS, are more likely to develop skin cancer.
  • Also, people who take drugs that suppress body's immune system, usually after an organ transplant, have an increased risk.
  • Exposure to radiation: Your chances of developing skin cancer, especially basal cell carcinoma, increases significantly if you have undergone radiation therapy for treatment of different conditions, such as eczema and acne.
  • Exposure to certain substances: You are more likely to get skin cancer if you are exposed to toxic substances such as arsenic.

8 Related Clinical Trials