Melanoma Skin Cancer


Melanoma Is the Deadliest Skin Cancer

Melanoma is a scary word. It’s a word you never want to hear during a visit to the dermatologist. Unfortunately, the number of cases of melanoma skin cancer are increasing rapidly. Whether it’s due to better detection in the early stage of this highly treatable cancer or increased sun exposure and other factors causing the rise in melanoma diagnoses, the answer isn’t clear. It’s clear that melanoma is the most dangerous form of skin cancer. Melanoma kills over 10,000 Americans a year. In 2016, melanoma will be diagnosed 135,000 times, of which about 76,000 cases will be invasive. (1)

melanoma

A classic melanoma lesion showing asymmetry, irregular borders, color variegation, and large diameter.

How does melanoma skin cancer develop?

Melanoma arises from the melanocytes; these are the cells that create pigment (melanin) in your skin. When the melanocytes become mutated, they can transform into cancerous cells and lead to full blown melanoma. Mutations in cells are normal as you age. However, the sun can cause mutations to occur more often and build up sooner than they should have. DNA damage induced by UV light is the major cause of skin cancer.

The melanocyte sits at the bottom of the epidermis.

The melanocyte sits at the bottom of the epidermis. https://upload.wikimedia.org/wikipedia/commons/d/dd/Illu_skin02.jpg

What are the different types of melanoma?

There are 4 main subtypes of melanoma. (2) They vary in incidence in different groups of people. There are other types of melanoma that are much more rare such as amelanotic, vulvar, and vaginal melanoma. The four main types of melanoma are:

1) Superficial Spreading: This is the most common type and occurs in 70% of melanoma cases. True to its name, this type of melanoma spreads superficially on the top most layer of skin. This means that if caught early you have a good chance of being cured with simple excision. Superficial spreading melanoma can begin within a mole that was previously benign. This is the type you see in a 25-year-old with a history of indoor tanning.

2) Lentigo Maligna: This type of melanoma is similar to superficial spreading melanoma because it grows on the top layer first. This is the type that most commonly occurs in elderly people with chronic sun exposure.

3) Acral Lentiginous: This type of melanoma is different because instead of starting on the skin it can commonly appear under the nails, on the soles of the feet, or on the palms of the hands. This is the type that’s more common in dark-skinned people, but also more deadly because it can advance more quickly. It is least common in Caucasians.

4) Nodular: This is the worst type to have at diagnosis. This is usually invasive from the onset. Like its name, the diagnosis usually comes after the patient notices a dark bump. Unfortunately, these tend to develop in areas that weren’t chronically exposed to the sun. The can arise in hard to monitor areas like the back.

melanoma skin cancer epidemiology-prevention-treatment-infographic

What are the risk factors for melanoma skin cancer?

Fair skin and family history of melanoma are important risk factors. (3) However, dark-skinned people (like Hispanics and African Americans) can also develop melanoma. These melanomas are more likely to be at an advanced stage when found.

If you have a long history of sun exposure and frequent sunburns you are at higher risk. UV light is to blame. Persons with a lot of moles (even ones which may be benign) have a higher chance of developing melanoma. Indoor tanning is another big risk factor. Young women are one of the fastest growing segments of the population being diagnosed with melanoma. It’s highly likely that this is due to indoor tanning use. In fact, melanoma is the most common cancer among people ages 25-29. Being diagnosed with melanoma at this early age puts you at a high risk of developing recurrent melanoma or other skin cancers like basal cell carcinoma and squamous cell carcinoma later in life. A weakened immune system due to HIV/AIDS, organ transplants, or immunosuppressive drugs can also increase the risk of melanoma.

Why is melanoma so deadly?

Melanoma is not deadly in the beginning. Melanoma will grow on the surface of the skin and spread outward for a time. Then all of a sudden the melanoma will start invading deeper into the skin and become a full blown metastatic cancer. Unfortunately, advanced melanoma has the tendency to metastasize. Not just to normal places like your brain, but to extremely odd places like the heart. Believe me, this is a very uncommon place for a cancer to metastasize. Many of the therapies for advanced melanoma aren’t great because the cancer doesn’t respond to it completely. The five-year survival rate for a stage 4 melanoma is only 15-20%. (4)

How can you check for melanoma?

Melanoma is almost 100% treatable if found early. The way to find melanoma is to visit your dermatologist once year for a total body skin exam. This way a doctor who is trained in spotting the warning signs of melanoma is able to evaluate you. You can also monitor any suspicious or new skin lesions using the ABCDE criteria.

These stand for asymmetry, irregular borders, color variegation, diameter >6mm, and evolving skin lesion. If you have any skin lesions that have any of these features, you should point it out to your doctor. Your doctor can decide whether the skin lesion is suspicious enough to warrant a biopsy. The only way to know and prove that a skin lesion is completely benign or possibly malignant is to biopsy it.

How is melanoma diagnosed?

You need a biopsy of the lesion in order to diagnose melanoma. Most times a lesion will be suspicious for melanoma and your doctor may remove it entirely with a certain border around it. The biopsy will be read by a dermatopathologist who will relay the information to your dermatologist. The biopsy will be able to provide a stage of melanoma diagnosis. This has to do with how deeply the melanoma has invaded into the skin.

Stage 0 means you have in situ melanoma. (1) This is the best kind to have because a simple excision will cure it.

Stages 1 and 2 mean the melanoma has gotten increasingly thicker but it hasn’t spread to the lymph nodes or other organs yet.

Stage 3 means melanoma has spread to either a lymph node or surrounding skin in close proximity.

Stage 4 has the worst prognosis because this means the melanoma has spread to either an internal organ or a lymph node that is farther away. A sentinel lymph node biopsy may be necessary to find out exactly how far the melanoma has spread.

How is melanoma treated?

If your melanoma is stage 0, you can do a simple excision or Mohs surgery. The width of the necessary margins gets bigger as you get to higher stages. When melanoma has spread to other parts of the body, treatment requires more extensive surgery or systemic treatments. Some of the treatment options include: chemotherapy, radiotherapy, and immunotherapy. The treatment will always depend on how much the melanoma has invaded into the skin.

How is melanoma prevented?

The easiest way to prevent melanoma is to avoid excessive sun exposure. Don’t tan (indoors or outdoors). Always wear your sunscreen. Know your ABCDE’s and apply them to your moles. And lastly, visit your dermatologist on a yearly basis for a total body skin exam or total body photography.

What did you learn about melanoma skin cancer that you didn’t know before? I’d love to hear your comments below!

References:

  1. American Academy of Dermatology. Melanoma.  https://www.aad.org/public/diseases/skin-cancer/melanoma
  2. Skin Cancer Foundation. Types of Melanoma. http://www.skincancer.org/skin-cancer-information/melanoma/types-of-melanoma
  3. Skin Cancer Foundation. Melanoma Causes and Risk Factors. http://www.skincancer.org/skin-cancer-information/melanoma/melanoma-causes-and-risk-factors
  4. American Cancer Society. Skin Cancer Survival Rates. http://www.cancer.org/cancer/skincancer-melanoma/detailedguide/melanoma-skin-cancer-survival-rates

Leave a comment

Your email address will not be published.

2 thoughts on “Melanoma Skin Cancer