Melanoma is a type of skin cancer that originates in cells called melanocytes. These cells produce the pigment melanin that controls skin pigmentation and protects skin from UV rays.
Melanocytes are evenly distributed in the bottom part of the epidermis, which is the uppermost layer of our skin. Moles are created by a concentrated accumulation of melanocyte. They are considered benign, but in certain cases may become cancerous.
When diagnosed on time, during its early stages, melanoma is highly treatable and five-year survival rate is around 90%.
However, when left undiagnosed melanoma may spread (metastases) through the lymph nodes and eventually affect the brain, liver, lungs, and other organs.
The incidence rate of melanoma is on the rise. Around 325,000 new cases worldwide are diagnosed annually.
What are the causes of melanoma?
One of the major causes of melanoma are UV rays from the sun. People with fair skin are at higher risk of developing this condition since their skin has less of the protective pigment melanin.
In addition, people who work outdoors, spend long periods of time outside, or sunbathe in tanning beds or lamps are also at higher risk.
People with many moles (especially atypical moles) are also at a greater risk for melanoma.
In some cases, people with a family history of melanoma are at risk for hereditary cancer (familial melanoma). Around 10% of cases are hereditary.
Melanoma and genetics
Research has found that in around 40% of hereditary melanoma cases, the cause was a mutation in the gene p16. This gene codes protein that regulates cell division. A single mutation in one of this gene’s alleles is enough to disrupt its function.
Accordingly, while the chances of developing melanoma in general population is around 1% (in individuals under age 50), people who are carriers of this gene mutation have a 50% chance of developing melanoma.
Why is genetic screening recommended?
Genetic screening can help people understand if they are at an increased risk for developing melanoma and take precautionary measures accordingly. Some of the recommended steps after positive tests results are:
- Frequent observation and monitoring of moles by a dermatologist around 1 -3 times annually.
- Removing suspicious moles that may turn cancerous.
- Screening tests for other family members.
- Adherence to sun safety guidelines (avoiding exposure to sunlight during its stronger hours, applying sunscreen, etc.).
- Awareness to the p16 gene mutation and taking care of treating suspicious moles.
Tumor biopsy and testing
Up to now, we have discussed melanoma risk assessment methods. However, it is important to be aware of different tests for determining the most suitable treatment of existing tumors.
A sample, also known as a biopsy, is taken from the cancer tissue, and tested. Among common tests are FoundationOne, BRAF mutation testing, and more. These tests help assess the effectiveness of treatment options for specific tumors.