Types Of Skin Cancer

Skin cancer, the cancer begins in cells that make up the skin. The skin is the body's largest organ. It protects us against heat, light, injury, and infection. It regulates body temperature and stores water, fat, and vitamin D. With skin cancer, new cells form when the skin does not need them, and old cells do not die when they should. These extra cells form a mass of tissue called a tumor. Not all tumors are cancer. Tumors that are cancer can invade and damage nearby tissues and organs, and sometimes can spread to other parts of the body.

Skin cancer is the most common type of cancer in the United States. About one million Americans get it each year. The number of new cases of skin cancer appears to be rising each year. The number of deaths due to skin cancer, though, is fairly small. The good news is that skin cancer is now almost 100 percent curable if found early and treated promptly.

Ultraviolet (UV) radiation from the sun is the main cause of skin cancer. Other sources of UV radiation, such as sunlamps and tanning booths, also can cause skin cancer. Although anyone can get skin cancer, the risk is greatest for people who have:

• Skin that tans poorly or burns easily
• A large number of moles, especially abnormal moles

Most skin cancers appear after age 50. But the sun's damaging effects begin at an early age. So, protection should start in childhood to prevent skin cancer later in life.

The types of skin cancer are:

Actinic Keratosis: Precursor to Squamous Cell Carcinoma

• Rough, red or pink scaly patches on sun-exposed areas of the skin,usually <0.5cm in diameter
• Precurser lesion for squamous cell carcinoma (Squamous Cell Carcinoma)
• Up to 1% of these lesions can develop into a Squamous Cell Carcinoma

Basal Cell Carcinoma :

• Raised, pink, waxy bumps that may bleed following minor injury
• May have superficial blood vessels and a central depression
• Locally invasive
• Rarely metastasizes
• Organ transplant recipients have a 10-fold higher risk for Basal Cell Carcinoma compared to the general population

Melanoma:

• Neoplasm of pigment (melanin) producing cells
• Brown or black skin lesion with irregularities in symmetry, border and coloration
• Prognosis dependent on depth of invasion
  ~100,000 new cases of melanoma are diagnosed in the United States each year
• Only 4% of diagnosed skin cancer, but 77% of skin cancer related deaths
• Organ transplant recipients have a 3 to 4-fold higher risk for melanoma compared to general population
  ◊  Melanoma accounts for ~6% of post transplant skin cancers in adult transplant recipients
  ◊  Melanoma accounts for 12-15% of post transplant skin cancers in pediatric organ transplant recipients
  ◊  Transplant recipients with a pre-transplant history of melanoma have a high risk of recurrence (~20%)

Kaposi's Sarcoma (KS):

• Rare, cancer of the cells that line blood vessels (endothelial cells)
• Clinically: brownish-red to blue colored skin lesions found most frequently on legs and feet
• Caused by Human Herpes Virus 8 (HHV-8) which causes the cells that line blood vessels (endothelial cells) to become cancerous in the setting of profound and prolonged immunosuppression
• Typically occurs in patients of Middle Eastern, Jewish, Mediterranean or African descent where HHV-8 in endemic
• Two main forms of KS exist
  Cutaneous/Mucocutaneous
  ◊  Most common form than occurs in adult transplant patients
  ◊  Most adult cases occur within 1-2 years following transplantation
  ◊  Treatments include reduction in immunosuppression and rapamycin
  Visceral
  ◊  Most common form that occurs in pediatric transplant patients
  ◊  Most pediatric cases occur while the patient is < 18 years old
  ◊  KS tumors can affect the gastrointestinal system, lymph nodes and lungs
  ◊ The visceral form is considered more serious than the cutaneous/mucocutaneous form

Squamous Cell Carcinoma:

• Most common skin cancer affecting transplant patients
• Dull red, rough, scaly raised skin lesions
• Occur most frequently on sun exposed areas (head, neck, ears, lips, back of the hands and forearms)
  ◊Sites particularly associated with elevated risk for recurrence or metastasis include: ear, lip/perioral, nose, periorbital, genitalia
• Most common skin cancer that occurs in pediatric and adult transplant recipients
  ◊  Ratio of Squamous Cell Carcinoma:Basal Cell Carcinoma = 3:1, opposite to the general population
  ◊  Squamous Cell Carcinoma tumors can grow very rapidly
  ◊  Mutiple cancers can occur simultaneously
  ◊  Squamous Cell Carcinoma tends to be more invasive and more aggressive in transplant patients
• Organ transplant recipients have a 65-fold higher risk for Squamous Cell Carcinoma and 20-fold higher risk for Squamous Cell Carcinoma of the lip compared to the general population
  ◊  Adult transplant patients tend to develop Squamous Cell Carcinoma 5-7 years following transplant
  ◊  Pediatric transplant patients (patients who received their transplants before the age of 18) tend to develop Squamous Cell Carcinoma an average of 10 years following transplant
  ◊  Pediatric transplant patient have higher risk for Squamous Cell Carcinoma of the lip compared to adult transplant patients
• Local recurrence rate ~13% in adult transplant patients
• Metastatic rate ~2% in general population
  ◊  5-7% in adult organ transplant patients
  ◊  13% in pediatric organ transplant patients