There are three types of skin cancer: basal cell (the most common), squamous cell and melanoma. One in five people will be diagnosed with skin cancer in their lifetime. Most skin cancers are caused by exposure to ultraviolet (UV) light (for example, sun exposure and/or tanning beds).
Melanoma is the deadliest type of skin cancer, but if detected early, it has a high likelihood of a cure. Melanoma rates have been steadily increasing over the past 30 years (SEER data 1975-2012). According to the National Cancer Institute, Oregon has one of the highest rates of melanoma in the country with more than 1,100 cases per year (2008-2012). It is most common in Caucasian men 65 years and older. However, more people under the age of 35 are diagnosed with melanoma than any other cancer (including breast, colon or lung) and it is second to only breast cancer in the number of deaths it causes (SEER data 2015).
What is melanoma?
What is melanoma?
Melanoma is a type of cancer that arises from pigmented cells. We have pigmented cells, called melanocytes, in many parts of our bodies, including the eye. Since most of these melanocytes are in the skin, the most common place for a melanoma to occur is in the skin. However, melanomas arising in other tissues, including the eye, such as Choroidal melanoma (also known as uveal melanoma), are different from melanomas of the skin.
If it is not treated, melanoma can spread to other parts of the body: This is called metastasis. Its ability to spread makes melanoma and metastatic melanoma the most serious form of skin cancer. Other types of skin cancer include basal cell carcinoma, merkel cell carcinoma and squamous cell carcinoma. If you have or suspect you may have melanoma or cancer that could be melanoma, you should see a dermatologist.
Types of Melanoma
Types of Cutaneous Melanoma
Melanoma is most commonly found on the skin (cutaneous) including soles of the feet, palms and under nails, but it can also be found in nostrils, mouth, genital areas (mucosal) and eyes (ocular).
|Type||Percent of all melanomas||Most commonly found||Comments|
|Superficial spreading||70%||Trunk and back on men, legs and back on women||Mole or pigmented area that changes over time|
|Nodular||10-15%||Men, especially over 60||More aggressive and develops more quickly|
|Lentigo maligna||5-10%||Face of middle to elderly-aged people who have sun damaged skin||May look like a sun spot, flat legion, various shades of color|
|Acral lentiginous||5%||Anywhere but also palms, under nails, soles of feet||Most common melanoma for people with darker skin. Musician Bob Marley died of this type of melanoma.|
Risk factors for Melanoma
Melanoma is caused by both environmental and genetic factors. Ultraviolet light (UV) is radiated energy or radiation that is present in sunlight. Suntans, sunburns and freckles are examples of over-exposure to sunlight and can increase the risk of skin cancer. There are two types of damaging UV rays – UVA and UVB. Limiting exposure to both UVA and UVB light with sun protective clothing, hats, sunglasses, sunscreen and seeking shade is recommended. Some people have a genetic mutation that makes them more susceptible to melanoma.
Anyone can develop melanoma, even people with darker skin types, but higher risk factors are:
- Having a fair complexion:
- Fair skin that freckles and burns easily, does not tan or tans poorly
- Blue or green or other light-colored eyes
- Red or blond hair
- Long-term exposure to natural or artificial sunlight
- A history of blistering sunburns, especially as a child or teenager
- Having several large or many small moles
- A family history of unusual moles (atypical nevus syndrome) or melanoma
- Having certain changes in the genes that are linked to melanoma
Consider talking to your doctor about a genetic test if the “rule of 3’s” applies to you. Watch this video from Dr. Sancy Leachman, melanoma program director at the OHSU Knight Cancer Institute, who explains who might want to consider genetic counseling or testing.
Most moles on your body are normal and harmless. However, if you notice a mole that changes in size, shape or color, has irregular edges, itches, oozes or bleeds, or becomes tender or painful, talk to your doctor.
Remember the early warning signs and melanoma symptoms with “ABCDE”:
- Asymmetry – one side of mole not like the other side
- Border – poorly defined, irregular shape
- Color – varies shades within the same mole (tan, brown, black)
- Diameter – more than 6 mm (size of a pencil eraser), though they can be smaller
- Evolving – any change, including but not limited to size, shape or color over time
If you have a mole or area of skin that appears abnormal, your doctor may have you undergo the following tests to check for melanoma:
Skin examDuring a skin exam, your doctor will examine your skin for moles, lesions, birthmarks, or areas that look abnormal in color, size, shape or texture. Many dermatologists use a dermatoscope which has a light and magnifies to see the skin more clearly. Photos are often taken to track changes over time.
BiopsyThis is a procedure to remove suspicious tissue. A pathologist looks at the tissue under a microscope to check for cancer cells. This can be done as during an office visit.
Sentinel lymph node biopsyThis surgical procedure may be recommended by your surgical oncologist, when the melanoma has more depth, to determine if it has spread to your lymph nodes. We work with the National Sentinal Lymph Node Working Group for people who need lymph node biopsy.
Protect Yourself: Be Safe in the Sun
Follow these simple tips:
- Wear clothing to protect your skin from the sun
- Use sunscreen
- Avoid tanning beds
- Learn how to do a self-skin check
- Pre-cancerous legions can be removed in during an office visit to keep cancer from developing
We also offer programs to help prevent melanoma
Mole mapping/pigmented lesions programWe offer a prevention program for people with a personal or family history of melanoma or abnormal moles. Our mole mapping program includes a thorough examination by a doctor who will note and record anything unusual. A medical photographer will take pictures of anything your doctor thinks should be examined again. You will have a photo record that your doctor can look at each year and that you can use to watch moles for signs of melanoma or suspicious changes.
Genetic counselingPatients with a family history of melanoma may be interested in learning more about family risk. OHSU geneticists can provide you with more information. To make a genetic counseling and risk assessment appointment call 503 494-4800.