1. Austin M. Luna and Mabel D’Souza
MENTORS: Malcolm J. D’Souza, Ph.D. and Dr. Fady Gerges, MD
Incidence and Prevalence of Melanoma (In-situ and Invasive) Along the Demographics Spectrum in Kent and Sussex Counties as Correlated with the BRAF Mutation Status
Abstract
Malignant Melanoma is regarded as one of the most significant skin cancer with higher rate of morbidity and even mortality. While the “in-situ” variant follows good prognosis if adequately excised, the invasive variants has the potential to metastasize and become potentially fatal. While many factors have been attributed to the etiology of melanoma including sun exposure, chemical, genetic predisposition, advanced age and others, a recently studied mutation BRAF V600E has been implicated in up to 60% of cases. Melanoma in the state of Delaware and due to unexplored epidemiological reasons, as per the most recent literature review, is perceived to be on the rise in all its forms. We conducted a thorough review of the malignant melanoma cases between September 2015 and July 2016 received at Green Clinics Laboratory (GCL) based in Dover, DE with special emphasis on Kent and Sussex counties. We ran immunohistochemical analysis of the BRAF mutation status on all confirmed melanoma cases. Data analysis, including patient demographics, melanoma variant, and clinical outcome when available, are correlated with the BRAF mutation status and plotted against geographic patient location. Inherent bias is factored in including demographic shifts in and out of state. Analysis of the data confirms the rise of melanoma within the counties in question and elucidate the significance of BRAF V600E mutation in the studied patients.
Signs of Melanoma
Stages of Melanoma A B C D E
Asymmetry – If you draw a line through the middle of a mole and it is asymmetrical is a warning sign for melanoma.
Borders – If a mole has uneven edges it is a warning sign for melanoma.
Color – Having multiple shades of brown within a mole is a warning sign for melanoma.
Diameter – If a mole has a large diameter (>5mm) it is a warning sign for melanoma.
Evolving – If a mole changes in size, color, edges, and/or shape these are warning signs for melanoma.
BRAF Mutation Status
Epidemiology
Results
National and state data
National and state data
Our findings
Our findings
Immunohistochemical analysis targeting the V600E BRAF mutation was performed on all the included cases (superficially spreading melanoma, nodular melanoma and malignant melanoma in situ). Tests where resulted as positive or negative as compared to a known positive control. BRAF mutation was more prevalent in the younger age groups (50% in the below 50 age group and 48% in the 50 to 70 age group) as opposed to 30% in patients above 70. Male to female ratio was one-to-one with 40% of males and females testing positive. 61% of invasive melanoma patients show positive staining for the BRAF mutation as opposed to 13% of in situ melanoma.
BRAF mutation is present in almost 50% of malignant melanoma (5, 4). 80% of those mutations are the substitution of Valine to glutamic acid at exon 600 thus BRAF V600E mutation (4,5 and 6). Several modalities have been used to test for the BRAF mutation including in-situ hybridization, immunohistochemistry and PCR (2). Immunohistochemical analysis (IHC) is a very rapid and cost-effective way for detecting the mutation with high sensitivity and specificity (6). Due to recent treatment advances linked to the type of mutation in malignant melanoma (3), in particular the BRAF V600E mutation (6), personalized medicine has changed the prognosis in these patients with BRAF inhibitors such as Vemurafenib (2). While not consistently implicated in causing the BRAF mutation, melanoma is more prevalent in UV exposed skin sites especially with intermittent exposure and patients with poor tanning response (5). The mutation is detected more frequently in malignant melanoma patients less than 55 years of age. It is more prevalent in superficially spreading and nodular melanoma as opposed to in-situ melanoma (4, 5 and 6). It has a prognostic implication with lower survival in patients with BRAF V600E mutation especially in a metastatic setting.
Malignant melanoma claims the life of one individual every hour in the USA (1). It ranks as #6 in the most common diagnosed malignant neoplasms and is regarded as one of the most deadly skin cancers (8,1). One of the worst characteristics is the average age of onset which is about 52 (1). Studies have shown gender disparity with 1 ½ to 2 × more prevalence of malignant melanoma in males (8). In the state of Delaware newly diagnosed cases in 2016 are projected to be around 320 (8). Delaware incidence rate is markedly higher than the U.S. rate in the order of 65% increase in the past 2 decades as opposed to 20% (7, 9). In Delaware, between 2009 and 2013, there was an average of 102 cases in Sussex County as compared to 45 cases in Kent County. This is age-adjusted to 35.4 cases per 100,000 incidence rate as compared to 25 per 100,000 respectively (10).
We conducted our demographic/epidemiology arm of the malignant melanoma study in the state of Delaware focusing on Sussex and Kent Counties. All confirmed malignant melanoma cases (both in situ and invasive) within the files of the Green clinics laboratory where pulled from September 1st 2015 till July 31, A total of 43 cases where identified of which 9 cases did not make the study. 34 cases were analyzed and showed even distribution between Sussex and Kent Counties. The newly diagnosed cases clustered in accordance with a population distribution concentrating around Lewis area and Rehoboth beach in Sussex County however Kent County cases were oddly distributed south of Dover. While the majority of the cases were in the 50 to 70 years old age group (17 out of 34) the below 50 age group showed more invasive melanoma (3 out of 4) with the majority of cases above 70 years of age being in situ (8 out of 13). Our male to female ratio was 21/13 however 60% of cases in females were invasive as opposed to 48% in males.
Acknowledgements
References
Conclusion
Thanks to Wesley College and Green Clinics Laboratory for the Internship opportunity.
Financial support was provided through the Delaware INBRE (IDeA Network of Biomedical Research Excellence) program funded by an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences - NIGMS at the National Institutes of Health (NIH) and the State of Delaware DEDO program under grant number P20 GM
Financial support was provided by the National Science Foundation S-STEM DUE grant through Wesley College’s Cannon Scholar program under award number and the State of Delaware DEDO program.
our findings mirrored the national averages of malignant melanoma with respect to gender disparities, incidence of BRAF mutations (in insitu and invasive melanoma) and age distribution; however our projected tended to be higher with respect to incidence and prevalence as compared to national and state projections. It is beyond the scope of this study to understand the significant of this increase in the state of Delaware particularly in Sussex and Kent County. As our studies are conducted from the files of one out of 5 main outpatient laboratory in the state of Delaware, it should be noted that if our malignant melanoma numbers are adjusted to the total number of skin biopsies received by the testing lab, the result will be in support of the above claims. On the other hand the ease by which we were able to test and gather data for the BRAF mutation in the included patients is a further indication for our ability in the 1st state to join the trend of personalized medicine. Studies have shown that targeted treatments of the advanced malignant melanoma cases will significantly change the outcome.