Basal Cell Carcinoma Gene Mutations Differ Between Asian, Hispanic, and Caucasian Patients: A Pilot Study

May 2021 | Volume 20 | Issue 5 | Original Article | 504 | Copyright © May 2021


Published online April 30, 2021

Marissa Lobl BSa, Blake Hass BSb, Dillon Clarey MDa, Shauna Higgins MDa,c, Adam Sutton MD MBAa, Ashley Wysong MD MSa,c

aUniversity of Nebraska Medical Center, Department of Dermatology, Omaha, NE
bUniversity of Nebraska Medical Center, College of Medicine, Omaha, NE
cUniversity of Southern California, Keck School of Medicine, Los Angeles, CA

Abstract
Background: Basal cell carcinoma (BCC) is the most common malignancy worldwide. While most BCCs are treated surgically, advanced BCCs are often treated with gene-targeted therapies. While there has been a lot of research in BCC from Caucasian patients, research is lacking in patients with skin of color.
Objective: To identify potential variations in BCC gene mutations between Asian, Hispanic, and Caucasian patients.
Methods: A cohort study was performed from 2015 to 2017 with 23 patients treated for BCC at an urban academic hospital. Gene mutations were assessed using a targeted mutation panel for 76 cancer-associated genes from formalin-fixed paraffin-embedded (FFPE) samples.
Results: Groups studied comprised Asian (n=5), Hispanic (n=10), and Caucasian (n=8) patients. The Hispanic cohort had the highest number of mutations per patient on average (3.4 versus 2.8 for both Caucasian and Asian cohorts). GATA3 mutations were more prevalent in Hispanic patients (P=0.02, single factor ANOVA). ARID1A and PTEN mutations co-occurred in the Hispanic cohort (P<0.05). The most common mutation in the Asian cohort was TP53 (2/5). The Caucasian cohort had the highest percent of UVB mutations (68.4%).
Conclusions: This study shows potential differences in the prevalence of somatic gene mutations for BCC patients of different races and ethnicities, which could inform the underlying pathogenesis, impact the efficacy of therapies in specific populations, and may also help identify novel therapeutic targets.

J Drugs Dermatol. 20(5):504-510. doi:10.36849/JDD.5884

INTRODUCTION

Basal cell carcinoma (BCC) is the most common malignancy in the United States with approximately 4.3 million cases each year.1-3 Nonmelanoma skin cancer, 80% of which are BCC, compose more malignancies than all other cancers combined.1,2,4,5 BCC has good outcomes when detected early, with a cure rate of up to 99% with Mohs micrographic surgery (MMS) and a standard cure rate goal of 95% across all treatment modalities.6,7 Although the mortality rate from BCC is relatively low at an estimated 0.12%, BCCs can become locally invasive and destructive, resulting in significant patient morbidity.8,9

While more prevalent in fair-skinned Caucasians, BCC is also present in populations with skin of color. Despite the increasing incidence of BCC in skin of color, these patients are often underrepresented in clinical trials, with an average of less than 10% of clinical trial participants being minorities.10 To our knowledge, no published studies have evaluated differences in specific somatic gene mutations in BCC for patients of different races and ethnicities. This pilot study aims to analyze the somatic gene mutations and how they might differ between Caucasian, Asian, and Hispanic patients.

MATERIALS AND METHODS

The authors’ Institutional Review Board approved all human studies. A cohort of 23 patients from an academic medical institution was used for this study. Patients were divided by race and ethnicity into three groups based on medical records: Asian (n=5), Hispanic (n=10), and Caucasian (n=8). BCC tissue was obtained from each patient, and formalin-fixed paraffin embedded (FFPE) samples were created. A board-certified pathologist evaluated hematoxylin and eosin-stained sections of the samples to determine percent tumor content in areas selected for extraction. Data was obtained using the Sentosa SQ Oncology Panel (Vela Diagnostics, Fairfield, NJ), a next generation sequencing based assay. Sentosa SQ Reporter software (Vela Diagnostics) was used to perform secondary analysis (variant calling, report generation), which filters to 5%