INVITED SPEAKERS ABSTRACTS
Genetic testing and patient counseling in melanoma
Familial melanoma represents less than 10% of all melanoma cases, but in these families, the risk to develop melanoma is very high from X100 to X1000 compared with general population. In a familial context also increases the number of primary melanomas developed and decreases the age of onset. As the risk is inherited as an authosomal dominant treat with incomplete penetrance and at least 2 major genes of familial melanoma are known (CDKN2A and CDK4), genetic counseling may be considered. Genetic counseling/assessment is a non-directive process in which information of the inherited risk to develop melanoma is offered to melanoma families together with the possibility to be submitted to a genetic testing, evaluating risks and benefits of the information obtained with the test. Genetic assessment may be also offered without the genetic testing because most of the importance of the process is the improvement in the knowledge of the risk and the strategies to control risk with primary and secondary prevention.
The requirements to consider a family as melanoma family varies according to the prevalence of melanoma in a specific population. Usually the rule of 2 is used in low prevalence countries (the presence of melanoma in 2 first degree relatives; or 2 primary melanomas in one patient; or one melanoma and one pancreatic adenocarcinoma; or more than 2 cases in the same side of a pedigree); the rule of 3 in medium prevalence countries (the presence of melanoma in 3 first degree relatives; or 3 primary melanomas in one patient; or 2 melanoma and one pancreatic adenocarcinoma; or more than 3 cases in the same side of a pedigree); and the rule of 4 may be considered in high prevalence countries. Genetic assessment includes a psychological evaluation, a dermatological surveillance and specific information for the patient. Genetic testing only should be performed in an affected individual. The identification of a causative mutation allows the spreading of the study to other members of the family to identify asymptomatic carriers, allowing an appropriate prevention and surveillance of at risk patients. The use of imaging techniques in specific surveillance programs facilitate the early detection of melanoma decreasing the number of unnecessary excisions and increasing the feeling of control of the risk that perceive the patients. Finally, genetic assessment in melanoma has shown an increase of the adherence to sun protection attitudes and dermatological surveillance in positive patients as well as in negative ones.© 2010 Lippincott Williams & Wilkins, Inc.