Melanoma is the fifth most common cancer. While it only accounts for 1% of skin cancers in the United States, it is the cause of most skin-cancer-related deaths. Here, we discuss five things you need to know about melanoma based on the latest findings in research.
In 2017, an estimated 87,110 Americans and 7,200 Canadians were diagnosed with melanoma skin cancer. It is the most common Melanoma skin cancer starts in the melanocytes of the skin. The melanocytes are the cells that create melanin. Melanin is the pigment that gives skin, eyes, and hair their colour. Changes in melanocytes can result in melanoma skin cancer.
A recent article published in the Canadian Medical Association’s journal CMAJ discussed five things to know about melanoma based on the recent findings in research. We discuss these five findings below.
1. Sun exposure plays an important role in the development of melanoma
Recent studies found that sun exposure is an important factor in the development of melanoma. Because of this, melanoma often appears on sites of the body that receive the most sun exposure. These areas include the neck, arms, and torso.
2. Melanomas can also occur on body sites not often exposed to the sun
Genome-sequencing studies found that melanoma can also occur on parts of the body that are not frequently exposed to the sun. These areas include the palms and soles of the feet. These findings indicate that while most melanomas are associated with sun exposure, cancer does occur in areas that do not receive as much sunlight. This means that sun exposure may not be the primary driver of melanoma.
3. A certain cellular pathway occurs in almost all melanomas Â
Researchers have found that a cellular pathway called the mitogen-activated protein kinase pathway is involved in almost all melanoma cases. This pathway stimulates the growth and survival of cancerous cells.
Using this pathway, genome-wide studies have identified important markers for the diagnosis and treatment of melanoma. The latest findings have provided hope that immunotherapies and targeted therapies aiming at this pathway may improve the survival of patients with advanced melanoma.
4. Ten per cent of melanomas are challenging to diagnose
Of all melanoma types, 10% are amelanotic or hypopigmented. Amelanotic melanoma results from a mole that does not contain melanin, and hypopigmented melanoma results from patches of skin that are lighter than an individual’s overall skin tone.
These two types of melanoma often occur in people with Fitzpatrick type I skin and chronic sun damage. They are often located in sun-exposed areas such as the face, neck, upper arms, and hands. These types of melanomas are difficult to diagnose because they may be pink, red, clear or normal skin-coloured.
5. Physicians should refer individuals with suspicious skin lesions to dermatology
The authors note that any skin lesion that fulfils the ABCDE criteria should be considered suspicious for melanoma.
The ABCDE critera stands for:
- Asymmetric shape
- Irregular border
- Colour variation
- Diameter greater than 6 mm (about the size of a pencil eraser)
- Evolution (any change)
Written by Jessica Gelar, HBSc
References:
- Micieli, Robert, and Kucy Pon. “Melanoma”. Canadian Medical Association Journal, vol 191, no. 19, 2019, pp. E535-E535. Joule Inc., doi:10.1503/cmaj.181500.
- “What Is Melanoma Skin Cancer? – Canadian Cancer Society“. Www.Cancer.Ca, 2019, https://www.cancer.ca/en/cancer-information/cancer-type/skin-melanoma/melanoma/?region=nu.
