- What is familial melanoma?
- When is familial melanoma suspected?
- How is a predisposition to melanoma inherited?
- What is the possibility of inheriting a genetic mutation?
- What is genetic testing for hereditary cancer for patients with suspected familial melanoma?
- How I can access the genetic testing programme for familial melanoma?
- What is the process?
- What results does this test give?
- Will I benefit by agreeing to this testing process?
- Am I obliged to take part?
- What will happen to my personal data?
- What can be done to reduce my risk of developing melanoma?
Melanoma is a type of skin cancer that, if detected early, can often be treated successfully.
"Familial melanoma" is a term that refers to families in which melanoma occurs to first-degree relatives (parents, children or siblings) in two or more cases.
Melanoma itself is not hereditary, but several members of the same family may be affected, and so the risk of inheriting it can develop. Hence it is important to know the family history of melanoma, since between 5% and 10% of diagnoses are made in the group of familial melanoma.
Familial melanoma is suspected in the following cases:
- If two or more family members have melanoma or other possibly related tumours (neoplasm of the pancreas, central nervous system tumours, others).
- If two or more melanomas occur in the same person (different tumours, different locations).
Each cell has two copies of each gene: one inherited from the mother and one from the father. To have a predisposition to familial melanoma, only one of the copies of the gene needs to carry a mutation (autosomal dominance), regardless of the sex of the person.
A person carrying a gene mutation can pass on one copy of the normal gene and one copy of the mutated gene to their children. Therefore, a child with a carrier parent of a genetic mutation has a 50% chance of inheriting it. Likewise, both the siblings and parents of a person with a genetic mutation have a 50% chance of having the same mutation.
Not all family members with melanoma carry the genetic alteration, and so when an alteration is identified in such a person a broader study can be conducted to determine whether the other members have inherited it.
It is important to note that having this predisposition does not necessarily mean that melanoma will develop.
For more information, visit www.genomel.org
The process of genetic testing includes three basic dimensions:
- Understanding the significance of familial melanoma.
- Understanding the relation between heredity and personal risk of developing melanoma and passing this risk on to descendants.
- Providing the necessary information to make decisions independently.
The best way to access the programme is through the healthcare professionals of the Primary Care Centre (CAP).
Both the patient and the family suspected of having a hereditary predisposition to familial melanoma may undergo genetic testing at the Melanoma Unit of the Hospital Clínic de Barcelona, where a multidisciplinary team of dermatologists, biologists, nurses and psychologists will study the case.
During the first visit you will be given the information needed to understand the relation between heredity and personal and family risk of developing melanoma, and how this risk can be passed on to other family members. If you happen to be a candidate, you will have a blood taken or be asked to provide a saliva sample in order to determine the presence or absence of genetic alterations (of the genes known so far) related to familial melanoma susceptibility.
During the second visit you will be given the results of the genetic tests and proper support to continue with the study of the family environment.
A positive test result enables the study to be made of other family members, thus identifying risk carriers, who may benefit from preventive measures and proper monitoring.
A negative result is in itself meaningless, because the test is conducted only on the genes known thus far.
Regardless of whether a genetic mutation is found or not, the patient should be properly monitored according to his or her case.
The benefits of taking part in the programme are significant:
- You will learn about risk and the preventative measures to be followed.
- The medical examination will be more appropriate for the early diagnosis of melanoma, thus minimising interventions through the use of imaging techniques.
- You will receive appropriate treatment, if this becomes necessary.
- You will receive psychological treatment, if this becomes necessary.
- You will participate in research to improve knowledge about melanoma.
No, participation is completely voluntary, and you may stop the procedure at any time if it does not meet your expectations, without it affecting your treatment.
Your personal data will be kept confidential, and only you will receive the test result.
A risk factor is any circumstance that increases the likelihood of developing a disease. Having a genetic mutation associated with melanoma does not predict with certainty that a person will develop cancer; controllable risk factors also play an important role in the risk of developing melanoma. The sun and other ultraviolet light (like tanning booths) are the melanoma risk factors most able to be controlled.
You should avoid sun exposure, especially during the middle of the day, seek shady spots when outdoors, wear appropriate clothing and use sunscreen correctly.
The team of the Genetic Counselling for Melanoma Unit
The team of the Unit for Genetic Testing for Familial Melanoma at the Hospital Clínic is led by Dr Susana Puig, Research Coordinator of the Melanoma Unit of the Department of Dermatology at the Clinical Institute of Internal Medicine and Dermatology (ICMiD), and Dr Josep Malvehy, Coordinator of the Melanoma Unit at ICMiD, and healthcare professionals from different specialties, such as Dermatology: Susanna Puig, Josep Malvehy, Cristina Carrera, Paula Aguilera; Psychology: Melinda González of the Clinical Institute of Neurosciences; Biology: Joan-Anton Puig and Cèlia Badenas of the Biomedical Diagnosis Centre; and Nursing: Pablo Iglesias, Daniel Gabriel and Maria-Eugenia Moliner.