BRAF Mutation (V600E) Prevalence in Mexican Patients Diagnosed with Melanoma

Addressing the unmet needs of patients with BRAF-mutated melanoma in Latin America: Expert perspective

Melanoma represents an increasing public health burden with extensive unmet needs in Latin America (LA). A mutation in the BRAF gene is present in approximately 50% of all melanomas in White populations and is a target of precision medicine, with the potential to dramatically improve patient outcomes. Thus, increased access to BRAF testing and therapy is LA must be explored. At a multi-day conference, a panel of Latin American experts in oncology and dermatology were provided with questions to address the barriers limiting access to testing for BRAF mutation in patients with melanoma in LA, who may be eligible for targeted therapy to improve their prognosis. During the conference, responses were discussed and edited until a consensus on addressing the barriers was achieved. Identified challenges included ignorance of BRAF-status implications, limited human and infrastructural resources, affordability and reimbursement, fragmented care delivery, pitfalls in the sample journey, and lack of local data. Despite the clear benefits of targeted therapies for BRAF-mutated melanoma in other regions, there is no clear path to prepare LA for a sustainable personalized medicine approach to this disease. Due to melanoma’s time-sensitive nature, LA must aim to provide early access to BRAF testing and consider mutational status within treatment decision making. To this end, recommendations are provided and include establishing multidisciplinary teams and melanoma referral centers and improving access to diagnosis and treatment.

Variations in genetics, biology, and phenotype of cutaneous disorders in skin of color - Part I: Genetic, biologic, and structural differences in skin of color

Skin of color (SOC) populations include those who identify as Black/African, Hispanic/Latinx, Asian/Pacific Islander, American Indian/Native Alaskan, Indigenous Australian, Middle Eastern, biracial/multiracial, or non-White; this list is far from exhaustive and may vary between and within cultures. Recent genetic and immunological studies have suggested that cutaneous inflammatory disorders (atopic dermatitis, psoriasis, and hidradenitis suppurativa) and malignancies (melanoma, basal cell carcinoma, and cutaneous T-cell lymphoma) may have variations in their immunophenotype among SOC. Additionally, there is growing recognition of the substantial role social determinants of health play in driving health inequalities in SOC communities. It is critically important to understand that social determinants of health often play a larger role than biologic or genetic factors attributed to "race" in health care outcomes. Herein, we describe the structural, genetic, and immunological variations and the potential implications of these variations in populations with SOC. This article underscores the importance of increasing the number of large, robust genetic studies of cutaneous disorders in SOC to create more targeted, effective therapies for this often underserved and understudied population. Part II of this CME will highlight the clinical differences in the phenotypic presentation of and the health disparities associated with the aforementioned cutaneous disorders in SOC.

Immunohistochemical Investigation of Mutant BRAF V600E in Common Pigmented Skin Neoplasms, Study on a Sample of Iranian Patients

Background & Objective:

This study was designed for the first time for the detec- tion of mutant BRAF V600E and its correlation with clinicophathologic features in a sample of Iranian patients with pathologically proved pigmented skin neoplasms.

Methods:

82 paraffin-embedded blocks, including melanocytic nevi, malignant melanoma, Basel cell carcinoma, and squamous cell carcinoma were evaluated for BRAF V600E expression by immunohistochemistry in the patients admitted to Ibn Sina Hospital, in the city of Sari, Mazandaran province, North of Iran. The evaluation of immunohistochemical staining was performed by two of the authoring pathologists, and staining intensity was graded from negative (0), weak (1+), moderate (2+) to strong (3+). If twenty percent (or greater) of the tumor cells showed modest to strong cytoplasmic immunoreactivity (score 3+), the neoplasm was considered positive for this tumor marker.

Results:

Among 82 studied patients, 12 cases (60%) of the malignant melanoma group revealed a high intensity of immunostaining for BRAF V600E, while a signifi- cant expression of this marker did not occur in the other investigated skin neoplasm. A great relation between BRAF (V600E) expression and the histologic type of skin cancer was noted. No significant relationship with other parameters such as gender, age, and the grade differentiation of the non-melanoma skin cancer was found. BRAF V600E was weakly correlated with the Clark level of cutaneous malignant melanoma.

Conclusion:

This data provided further evidence for the strong role of the BRAF V600E mutation in the development of cutaneous malignant melanoma, compared to non-melanoma skin cancers in the North of Iran. We advised future studies to evaluate the beneficial effects of anti-BRAF V600E target therapy on the Iranian melanoma patient who harbors this marker by way of immunostaining tumor tissue.

Cutaneous melanoma in patients from western Mexico: Clinical pathology characteristics and their relationship to prognosis

BACKGROUND/OBJECTIVE

Melanoma is the third most frequent malignant neoplasm in skin. The majority of information available comes from studies performed in Caucasian populations. Our objective was to investigate the clinico-pathological characteristics in Mexican patients with cutaneous melanoma and the relationship these characteristics had to prognosis.

METHODS

A retrospective study included patients with a histopathological diagnosis of melanoma who were attended at a tertiary level Dermatology Institute over a 10-year period. Age, gender, anatomical location; histopathological subtype, Breslow thickness, Clark level; presence of ulceration, metastasis, anatomical-pathological stage and survival were investigated. To assess the data, descriptive statistics, chi-squared or the Fisher exact test and Kaplan-Meier curves were used.

RESULTS

There were 323 patients included. The overall survival rate was 77% with an average follow-up of 7 years. The lowest survival was statistically related to the following: higher age (>65 years), localisation in palms/soles, histopathological nodular subtype, presence of ulceration, Breslow thickness >4.0 mm, Clark level V, the presence of metastasis and stage IV disease.

CONCLUSIONS

Our results relay the characteristics and prognosis of patients with the diagnosis of cutaneous melanoma in western Mexico.

Frequency of BRAF V600E Mutation in the Mexican Population of Patients With Metastatic Melanoma

Purpose

The BRAF V600E mutation has been described in melanomas occurring in the Caucasian, European, and Asian populations. However, in the Mexican population, the status and clinical significance of BRAF mutation has not been researched on a large scale.

Methods

Consecutive BRAF-tested Mexican patients with metastatic melanoma (n = 127) were analyzed for mutations in exon 15 of the BRAF gene in genomic DNA by real-time polymerase chain reaction technology for amplification and detection. The results were correlated with the clinical-pathologic features and the prognosis of the patients.

Results

The frequency of somatic mutation V600E within the BRAF gene was 54.6% (43 of 127 patients). Nodular melanoma was the most prevalent subtype in our population, with BRAF mutations in 37.2% (16 of 55 patients). In contrast, superficial spread had a frequency of 18.6% BRAF mutation (eight of 24). Other clinicopathologic features were assessed to correlate with the mutation status.

Conclusion

This study searched for the most prevalent BRAF V600E mutation type in melanoma in a heterogeneous population from Mexico. Nodular melanoma was found to be the most prevalent in metastatic presentation and the presence of BRAF V600E mutation, perhaps related to the mixed ancestry; in the north, ancestry is predominantly European and in the south, it is predominantly Asian. The outcomes of the mutation correlations were similar to those found in other populations.