Why some moles become melanoma still a mystery

August 11, 2017
Why some moles become melanoma still a mystery
Half of all melanomas develop from a naevus. Credit: University of Queensland

Testing for two gene mutations commonly associated with melanoma would be insufficient to determine whether a mole could turn cancerous, University of Queensland research has found.

UQ Diamantina Institute's Dr Mitchell Stark is among researchers investigating why melanomas develop from some naevi (moles).

"In Australia, about half of all melanomas develop from a naevus, but most moles will never progress to become a melanoma," Dr Stark said.

"We are trying to determine what causes some naevi to change so that we can better predict or more accurately detect those which could become dangerous.

"This would help avoid unnecessary excisions of those lesions unlikely to pose a risk."

Scientists from UQ's Dermatology Research Centre analysed samples from participants in the Brisbane Naevus Morphology Study, and discovered all had one of two key associated with melanoma.

"We found that 85 per cent of samples had a mutation on the gene known as BRAF, and the remaining samples had a mutation on the NRAS gene," Dr Stark said.

"When either of these are mutated it activates the signalling pathway known as MAPK, which is commonly active in melanomas.

"Clearly our samples were not melanomas, so additional genomic events need to occur before a becomes malignant."

Dr Stark said further research was underway to determine other genetic changes that could trigger the development of melanoma from naevi.

Studies have consistently shown the number of naevi a person has is the strongest predictor of risk for .

Dr Stark said people with a high number of moles, and other risk characteristics such as fair skin or light coloured hair or eyes, should continue to see their treating dermatologist or skin cancer physician for routine skin examination.

The research was published in the British Journal of Dermatology .

Explore further: Now is the time for dermatologists to learn genomics

More information: J. M. Tan et al. The BRAF and NRAS mutation prevalence in dermoscopic subtypes of acquired naevi reveals constitutive MAPK pathway activation, British Journal of Dermatology (2017). DOI: 10.1111/bjd.15809

Related Stories

Now is the time for dermatologists to learn genomics

May 8, 2017
Dermatologists may need to look further than red hair and freckles when identifying patients who might be genetically predisposed to skin cancer.

Study of patients with melanoma finds most have few moles

March 2, 2016
Most patients with melanoma had few moles and no atypical moles, and in patients younger than 60, thick melanomas were more commonly found in those with fewer moles but more atypical moles, according to an article published ...

Researchers look to improve detection of skin cancer lacking pigment melanin

August 9, 2017
New findings from an international research team led by University of North Carolina Lineberger Comprehensive Cancer Center scientists may improve detection of skin cancer that lacks any brown or black color.

Using clinical features to identify patients at high risk for melanoma

November 9, 2016
Can an individual's risk factors for melanoma be used to tailor skin self-examinations and surveillance programs? A new study published online by JAMA Dermatology suggests they could by identifying those patients at higher ...

Moles can quadruple risk of developing melanoma

September 4, 2014
Having moles on your skin can quadruple your risk of developing melanoma, the deadliest type of skin cancer, according to a study released this week by experts at the University of Melbourne, University of Oxford, and the ...

Expression of specific gene differentiates moles from melanoma

November 21, 2016
Most melanomas are driven by mutations that spur out-of-control cell replication, while nevi (moles composed of non-cancerous cells at the skin surface) harboring the same mutations do not grow wildly. However, changes in ...

Recommended for you

Cancer immunotherapy may work better in patients with specific genes

December 15, 2017
Cancer cells arise when DNA is mutated, and these cells should be recognized as "foreign" by the immune system. However, cancer cells have found ways to evade detection by the immune system.

Scientists pinpoint gene to blame for poorer survival rate in early-onset breast cancer patients

December 15, 2017
A new study led by scientists at the University of Southampton has found that inherited variation in a particular gene may be to blame for the lower survival rate of patients diagnosed with early-onset breast cancer.

'Bet hedging' explains the efficacy of many combination cancer therapies

December 14, 2017
The efficacy of many FDA-approved cancer drug combinations is not due to synergistic interactions between drugs, but rather to a form of "bet hedging," according to a new study published by Harvard Medical School researchers ...

Scientists unlock structure of mTOR, a key cancer cell signaling protein

December 14, 2017
Researchers in the Sloan Kettering Institute have solved the structure of an important signaling molecule in cancer cells. They used a new technology called cryo-EM to visualize the structure in three dimensions. The detailed ...

Liquid biopsy results differed substantially between two providers

December 14, 2017
Two Johns Hopkins prostate cancer researchers found significant disparities when they submitted identical patient samples to two different commercial liquid biopsy providers. Liquid biopsy is a new and noninvasive alternative ...

Testing the accuracy of FDA-approved and lab-developed cancer genetics tests

December 14, 2017
Cancer molecular testing can drive clinical decision making and help a clinician determine if a patient is a good candidate for a targeted therapeutic drug. Clinical tests for common cancer causing-mutations in the genes ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

fey5
not rated yet Aug 11, 2017
Does damage, for example from ultraviolet light, produce signals that have remote effects. It would explain why sun exposure can increase melanoma risk on unexposed skin.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.