The number of detected skin cancer cases is growing at worrying rates. According to the US National Foundation for Cancer Research (NFCR), over the past three decades, more people have been diagnosed with a form of skin cancer than all other cancers together.
What is melanoma (skin cancer)? How common is it?
Melanoma is a type of skin cancer. While it is less common than other skin cancer types ― as it only accounts for 1% of skin cancers ― it causes the majority of skin cancer deaths. This is because of its ability to spread to other organs and parts of the body (metastasize) very quickly if not detected and treated early.
Melanoma starts in the melanocytes, which are skin cells found in the upper layer of our skin. These cells produce the melanin pigment that determines the skin’s color and protects the skin from the ultraviolet (UV) radiation emitted by the sun.
According to the American Cancer Society’s estimations in the USA, over 200,000 melanoma cases will be diagnosed in 2021. About half of these new melanomas will be noninvasive and confined to the top skin, and the rest of the cases will be invasive and could metastasize. Nearly 7,180 people in the USA are expected to die of melanoma by the end of 2021.
What are the symptoms of melanoma?
The first and most common sign of melanoma is a new mole on the skin – which happens in up to 80% of the cases – or a change in the appearance of an existing one. This may happen anywhere on the body, but the most commonly affected areas in women are the legs and in men are the back and chest, which are the areas most exposed to the sun. Normal moles usually have a round or oval shape with a smooth edge. In most cases of melanoma, moles have an irregular shape and more than one color. Other signs to look out for melanoma are the mole’s growth and whether it is bleeding, itchy or sore.
The ABCDE rule is an easy-to-remember system that outlines the warning signs of melanoma:
- A is for Asymmetry: Most melanomas are asymmetrical.
- B is for Border: The edges are irregular and uneven.
- C is for Color: The color is not the same all over and may include different shades of brown or black, or sometimes even pink, red, white, or blue.
- D is for Diameter: Melanomas may have a bigger diameter.
- E is for Evolving: The mole is changing in size, shape, or color.
If any of the above signs are noticed, a healthcare provider must be immediately consulted to determine whether a mole or growth may be cancerous. Detecting melanoma at an early stage is crucial and makes a significant difference. If detected early – when the cancer is on the surface of the skin – melanoma has an exceptional prognosis with a 5-year survival rate of 99%. The survival rate drops to 66% if the disease reaches the lymph nodes, and 27% if it has metastasized to distant organs.
How is melanoma treatment determined?
In most cases, a questionable mole is usually surgically removed and sent for a biopsy so it can be examined thoroughly. If the mole is diagnosed as cancerous, and the type of melanoma is classified, the next important step is the identification of the disease stage for treatment determination. This may require additional tests such as sentinel lymph node biopsy, PET and CT scans, MRIs, and blood tests. Several elements define the stage of melanoma such as how far the melanoma has grown into the skin, and if it has spread. A lower stage number means less progression of the disease.
What causes melanoma? What are risk factors?
Certain factors can increase the risk of developing melanoma. The most important risk factor is exposure to ultraviolet (UV) radiation light. The sun is the main source of this light, but tanning beds and sun lamps are also potential sources. Having many moles, fair skin or freckles may also raise the risk as these individuals are more sensitive to sunlight. Racial identity may also play a role, as melanoma is about 20 times more frequent in Caucasians than Africans. The risk of developing melanoma also rises when having a weakened immune system as a result of medical treatments or conditions. Melanoma is more likely to occur in older people rather than young people; the average age at the time of melanoma diagnosis is 65 years. Also, men have a higher rate of melanoma than women.
Genetics of melanoma
Gene mutations (changes) are also important risk factors for melanoma skin cancer. Mutations can be either acquired mutations that are caused by environmental factors, or hereditary mutations that exist in a person from birth and can be inherited from a parent. Having certain hereditary mutations raise the risk of developing melanoma. As hereditary mutations cluster in families, having a first-degree relative with melanoma may mean that more people in the family could also have a hereditary mutation that increases their risk of developing cancer. Overall, about 10% of newly diagnosed melanoma patients have a family history of the disease. The risk is greater for individuals if several members on one side of the family were diagnosed with melanoma and if a family member had more than one melanoma or had both melanoma and pancreatic cancer. In these cases, genetic testing can be beneficial as it can identify whether a mutation exists, and what risk factors could be avoided to reduce the risk of cancer developing in the future. Additionally, if an individual had melanoma in the past, then that person has a greater risk of developing melanoma again in the future. Lastly, a rare inherited condition called Xeroderma pigmentosum (XP) elevates the risk of developing melanomas and other skin cancers at a young age.
When diagnosed at an early stage, surgery is the main treatment for melanoma. If it is not diagnosed until it has progressed, treatment may include immunotherapy, chemotherapy, radiation therapy, and targeted therapy. A team of healthcare providers will recommend the best treatment option for each patient depending on the stage of melanoma.
How to treat genetic melanoma? Future outlook
In the past decade, medicines that are targeted toward specific mutations, such as the acquired mutation in the BRAF gene, have been successfully used to slow or stop cancer cells from growing. This explains why genetic testing for identifying the mutations responsible for melanoma, whether acquired or hereditary, can be beneficial. With the help of modern technologies, scientists are now able to develop vaccines for melanoma. These are currently only given as part of clinical trials, but in the future will be a novel and effective treatment option for melanoma cancer patients. The vaccine’s design is personalized for each patient as it is based on the genetic and molecular information obtained from the skin removed through a biopsy.
How to prevent melanoma?
There is no secure path for melanoma skin cancer prevention. Certain risk factors, like family history, cannot be controlled. For individuals who have a family history of melanoma, genetic tests for specific gene mutations associated with melanoma can determine whether someone has an increased risk of developing this disease. In that event, an informed course of action can be decided with a healthcare provider through appropriate precautions and frequent observations that may reduce the risk of cancer or help diagnose it early, when treatment is more beneficial. Awareness and prevention may reduce the risk of developing melanoma and other skin cancers. When spending time outdoors, limiting your exposure to UV rays is the most important way to lower the risk of developing skin cancer. This can be done by staying in the shade, wearing a hat, sunglasses, and protective clothing, and by using a broad-spectrum sunscreen lotion with SPF 30 or higher. Frequently performing self-skin checks to identify any new or abnormal moles can lead to an early diagnosis and increased chances of successful treatment. When a change is noticed, informing a healthcare provider as soon as possible can be lifesaving. Raising awareness and educating society regarding the risk factors and warning signs of melanoma is the best tool to prevent and reduce the number of skin cancers.
Please note: The content is intended only for educational purposes and should not be perceived as medical advice.
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