Skin Cancer

Skin cancer is a malignant tumor that grows in the skin cells. In the US, more than 1-million Americans are diagnosed with non-melanoma skin cancer each year according to the American Cancer Society. A majority of skin cancers cases appear in the elderly community, however skin damage from the sun begins at an early age. Therefore, protection should start in childhood to prevent skin cancer later in life.


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Overview

Anatomy of the skin

The skin is the largest organ of the body. Skin protects us from heat, sunlight, injury, and infection. It also stores water and fat, and produces vitamin D. The skin has three layers:

  • The outer layer called the epidermis
  • The middle layer called the dermis
  • The inner layer called the subcutis

The epidermis is made of flat cells called squamous cells. Round basal cells are under the squamous cells. The lower part of the epidermis also has pigment-producing cells called melanocytes, which darken the skin in response to sun exposure.
The dermis has blood vessels, lymphatic vessels, hair follicles, and glands. Some of these glands make sweat, which helps keep the body cool. Other glands make sebum. Sebum helps keep the skin from getting dry. Sweat and sebum reach the skin's surface through tiny openings called pores.
The subcutis and the lowest part of the dermis form a network of collagen and fat cells. This layer conserves heat and helps protect the body’s organs from injury.

What is skin cancer?

There are three main types of skin cancer:

  • Melanoma
  • Basal cell carcinoma
  • Squamous cell carcinoma

The most serious skin cancer is melanoma. Melanoma is a type of skin cancer that starts in skin cells called melanocytes. Melanocytes are what give skin its color. Melanoma is a much less common form of skin cancer than either basal cell carcinoma or squamous cell carcinoma. It is estimated that more than two million Americans will develop some form of skin cancer each year. This section deals with melanoma; see non-melanoma skin cancer for information on basal or squamous cell carcinoma.

People with melanoma, a serious form of skin cancer, now have more hope for survival and more treatment choices than ever before. Doctors keep finding new treatments for melanoma and ways to help people with melanoma lead better lives. They are continually learning more about melanoma and its prevention, detection, and treatment.

Symptoms of Skin Cancer

What to look for

To help find melanoma early, it is important to examine your skin on a regular basis, and become familiar with moles, and other skin conditions, in order to better identify changes. Certain moles are at higher risk for changing into malignant melanoma. Moles that are present at birth (congenital nevi), and atypical moles (dysplastic nevi), have a greater chance of becoming malignant. Recognizing changes in moles, by following this ABCD chart, is crucial in detecting malignant melanoma at its earliest stage. The warning signs are:

Normal mole / melanoma Sign   Characteristic
Asymmetry   When half of the mole does not match the other half
 
Border   When the border (edges) of the mole are ragged or irregular
 
Color   When the color of the mole varies throughout
 
Diameter   If the mole's diameter is larger than a pencil's eraser
Photographs Used By Permission:
National Cancer Institute
     

Melanomas vary greatly in appearance. Some melanomas may show all of the ABCD characteristics, while others may show few or none. Always consult your doctor for a diagnosis

How to perform a skin self-examination

Finding suspicious moles or skin cancer early is the key to treating skin cancer successfully. A skin self-exam is usually the first step in detecting skin cancer. The following suggested method of self-examination comes from the AAD:

(You will need a full-length mirror, a hand mirror, and a brightly lit room.)

  • Examine your body front and back in mirror, then the right and left sides, with your arms raised. Women should look under their breasts.
  • Bend your elbows, look carefully at your forearms, the back of your upper arms, and the palms of your hands. Check between your fingers and look at your nail beds.
  • Look at backs of your legs and feet, spaces between your toes, your toenail beds, and the soles of your feet.
  • Examine the back of your neck and scalp with a hand mirror.
  • Check your back, buttocks, and genital area with a hand mirror.
  • Become familiar with your skin and the pattern of your moles, freckles, and other marks.
  • Be alert to changes in the number, size, shape, and color of pigmented areas.
  • Follow the ABCD Chart when examining moles of other pigmented areas and consult your doctor promptly if you notice any changes

Normal and abnormal moles

Sometimes groups of melanocytes make moles, or nevi. Most people have some moles on their bodies. These moles are usually pink, tan, or brown. They can be flat or raised, and are usually round or oval. Most moles are on the chest or the upper part of the body. Moles do not usually grow or change very much. Many times, moles fade in older people. Most moles are benign, or noncancerous, and do not lead to cancer. Some abnormal moles, called dysplastic nevi, pose an increased risk of melanoma, and should be checked regularly by a doctor.

Cutaneous melanoma

Melanoma is the most serious kind of skin cancer. It starts when normal melanocytes become cancerous. When cancer cells are on the skin, the cancer is called cutaneous melanoma. Most of what we know about melanoma (its behavior, staging, and treatment) refers to cutaneous melanoma. Melanoma can occur anywhere on the skin. Men usually get it on the part of the body between the shoulders and the hips called the trunk. They may also get it on their head or neck. Women usually get it on their arms and lower legs. Sometimes, melanoma may occur even on areas of the skin that never are exposed to sunlight. It may even occur in the eye, under a finger- or toenail, or in the nose and sinuses. If left untreated, melanoma can spread to other parts of the body, such as the liver, lungs, or brain. If melanoma spreads to the liver, for example, the cancer cells in the new tumor are still melanoma cells. The disease is then called metastatic melanoma, not liver cancer.

Diagnosis & Treatment

Melanoma treatment introduction

A patient's treatment choices depend on the size and location of the melanoma and the stage or extent of the disease. A doctor also considers the patient's age and general health when deciding which treatment plan(s) to recommend. The patient considers these recommendations based on a range of personal factors as well.

Many people want to learn all they can about their disease and their treatment choices so that they can take an active part in decisions about their medical care. They are likely to have many questions and concerns about their treatment options. Most patients also want to know how they will function after treatment and whether they will have to change their normal activities.

The doctor may recommend a specific treatment or may offer more than one and ask the patient to decide which one he or she would like to follow. Patients often have a hard time making this decision. It is important that a patient take the time he or she needs to make the best decision.

The doctor is the best person to answer a patient's questions, such as what treatment choices are, how successful it is expected to be, and what the risks and side effects may be.

Treatment for melanoma may be local, systemic, or both. Local treatments remove, destroy, or control the cancer cells in one certain area. Surgery and radiation therapy are local treatments. Systemic treatments are used to destroy or control cancer cells throughout the entire body. Chemotherapy, targeted therapy, and biological therapy (immunotherapy) are systemic treatments. A patient may have just one treatment or a combination of treatments.

There are several kinds of treatments for skin cancer, including the following:

  • Surgery. Surgery is a common treatment for skin cancer. It is used in most treated cases. Some types of skin cancer growths can be removed very easily and require only very minor surgery, while others may require a more extensive surgical procedure. Surgery may include the following procedures:
    • Cryosurgery. Using liquid nitrogen, cryosurgery uses an instrument that sprays the liquid onto the skin, freezing and destroying the tissue.
    • Curettage and electrodesiccation. This common type of surgery involves scraping away skin tissue with a curette (a sharp surgical instrument,) followed by cauterizing the wound with an electrosurgical unit.
    • Excision. A scalpel (sharp surgical instrument) may be used to excise (cut away) and remove the growth. The wound is usually stitched or held closed with skin clips.
    • Mohs' microscopically controlled surgery. This type of surgery involves excising a lesion, layer by layer. Each piece of removed tissue is examined under a microscope. Tissue is progressively removed until no tumor cells are seen. The goal of this type of surgery is to remove all of the malignant cells and as little normal tissue as possible. It is often used with recurring tumors (those that come back after treatment).
  • Laser therapy. Laser surgery uses a narrow beam of light to destroy cancer cells, and is sometimes used with tumors located on the outer layer of skin.
  • Radiation therapy. X-rays are used to kill cancer cells and shrink tumors.
  • Photodynamic therapy. Photodynamic therapy uses a certain type of light and a special chemical to kill cancer cells.
  • Other types of treatment include the following:
    • Chemotherapy . Chemotherapy uses drugs to kill cancer cells.
      • Topical chemotherapy. Chemotherapy given as a cream or lotion placed on the skin to kill cancer cells.
      • Systemic chemotherapy. Chemotherapy administered orally or intravenously (IV) for more advanced cancers
    • Immunotherapy. Immunotherapy involves various approaches to boost the body's own immune system, helping it to attack the cancer. Some types of treatment can be applied on tumors or injected directly into them. Other types are used for more advanced cancers and are given as an injection into the vein (IV).
    • Targeted therapy. Some medicines used to treat advanced skin cancers work by targeting specific parts of the cancer cells. These medicines can often be taken as a pill.

Goals of treatment

It is important to understand the goals treatment. A number of treatments are available for melanoma. Patients will want to consider both the benefits and possible side effects of each option, and will want to discuss any other concerns they have with their doctor before making a decision.

Different types of treatments have different goals. Below is a list of treatments and their respective goals:

  • Surgery. The goal of surgery is to remove the melanoma, while leaving as much of the surrounding skin intact.
  • Radiation therapy.  The goal of radiation is to kill cancer cells using high energy X-rays or other radioactive particles. It can be used after surgery to try to kill any remaining cancer cells. It may also be used to help treat melanoma that has come back after initial treatment or has spread to distant parts of the body.
  • Chemotherapy. The goal of chemotherapy is to kill tumor cells directly to shrink tumors that cannot be removed by surgery or that have spread to distant areas of the body (this is called metastatic melanoma.) Chemotherapy may be used for other situations in clinical trial settings.
  • Biological therapy. Biological therapy (immunotherapy) includes treatment with substances that modify the immune system. Antibody therapy, vaccine therapy, and other treatments are examples and are based on specific knowledge of the biology of the tumor cells and of our bodies' defenses against them. Interferon and interleukin-2 (IL-2) have been used for many years. Both drugs can help shrink advanced (stage III and IV) melanomas in some patients when used alone. These drugs may also be given along with chemotherapy for Stage IV melanomas. Yervoy (ipilimumab) is a newer drug that boosts the immune system and has been shown to be helpful for advanced melanomas.
  • Targeted therapy. Some newer drugs target specific parts of melanoma cells. For example, a newer drug, called Zelboraf (vemurafenib,) targets a gene change found in about half of all melanomas. It can often cause advanced melanomas with this gene change to shrink.

Doctors are always finding new ways to treat melanoma. These new methods are tested in clinical trials. Before beginning treatment, a person should ask their doctor if there are any clinical trials they should consider.

At first, the information a patient receives about treatment options may seem overwhelming. It is important that patients take the time to gather as much information as possible about their disease and its treatment, and to discuss the issues with their doctors, nurses, and loved ones. Many people find it helpful to make a list of questions before seeing their doctor.

 

Prevention of Skin Cancer

The American Academy of Dermatology (AAD) recommends the following steps to help reduce your risk of skin cancer:

  • Wear protective clothing, including a long-sleeved shirt, pants, a wide-brimmed hat and sunglasses, when possible.
  • Seek the shade when appropriate, especially when the sun's rays are the strongest, from 10 a.m. to 4 p.m.
  • Regularly use a broad-spectrum sunscreen with an SPF (sun protection factor) of 30 or higher on all exposed skin, even on cloudy days. Sunscreen should be reapplied every two hours and after swimming or sweating.
  • Protect children from the sun by using shade, protective clothing, and applying sunscreen.
  • Use extra caution near water, snow, and sand, which can reflect the sun's rays and increase the chances of sunburn.
  • Avoid tanning beds. The UV (ultraviolet) light from tanning beds can cause skin cancer and wrinkling.
  • Check your birthday suit on your birthday. Look at your skin carefully and if you see anything changing, growing, or bleeding on your skin, see your doctor.
  • Get vitamin D safely through a healthy diet (which may include vitamin supplements.) Don't seek out the sun.

The American Academy of Pediatrics approves of the use of sunscreen on infants younger than 6-months old only if adequate clothing and shade are not available. Parents should still try to avoid sun exposure and dress the infant in lightweight clothing that covers most surface areas of skin. However, parents also may apply a minimal amount of sunscreen to the infant's face and back of the hands.
Remember, sand and pavement reflect UV rays even under an umbrella. Snow is a particularly good reflector of UV rays.

What are the risk factors for skin cancer?

Skin cancer is more common in fair-skinned people, especially those with blond or red hair, who have light-colored eyes. Skin cancer is rare in children. However, no one is safe from skin cancer. Other risk factors include:

  • Family history of melanoma
  • Personal history of skin cancer
  • Sun exposure. The amount of time spent unprotected in the sun directly affects your risk of skin cancer.
  • Early childhood sunburns. Research has shown that sunburns early in life increase a person's risk for skin cancer later in life.
  • Many freckles
  • Large or many ordinary moles
  • Dysplastic nevi
  • Male gender
  • An immunosuppressive disorder or weakened immune system (such as in people who have had organ transplants) 
  • Exposure to certain chemicals, like arsenic
  • Radiation exposure
  • Smoking
  • HPV (human papillomavirus)
  • Certain rare inherited conditions, such as basal cell nevus syndrome (Gorlin syndrome), or xeroderma pigmentosum (XP)