Epidermal growth factor receptor and KRAS mutations in Brazilian lung cancer patients

Abstract

OBJECTIVE:Epidermal growth factor receptor is involved in the pathogenesis of non-small cell lung cancer and has recently emerged as an important target for molecular therapeutics. The KRAS oncogene also plays an important role in the development of lung cancer. The aim of this study was to evaluate the frequency of epidermal growth factor receptor and KRAS mutations in a population of Brazilian patients with non-small cell lung cancer.METHODS:A total of 207 specimens from Brazilian patients with non-small cell lung cancer were analyzed for activating epidermal growth factor receptor and KRAS somatic mutations, and their associations with clinicopathological characteristics (including age, gender, ethnicity, smoking habits, and histological subtype) were examined.RESULTS:We identified 63 cases (30.4%) with epidermal growth factor receptor mutations and 30 cases (14.6%) with KRAS mutations. The most frequent epidermal growth factor receptor mutation we detected was a deletion in exon 19 (60.3%, 38 patients), followed by an L858R amino acid substitution in exon 21 (27%, 17 patients). The most common types of KRAS mutations were found in codon 12. There were no significant differences in epidermal growth factor receptor or KRAS mutations by gender or primary versus metastatic lung cancer. There was a higher prevalence of KRAS mutations in the non-Asian patients. Epidermal growth factor receptor mutations were more prevalent in adenocarcinomas than in non-adenocarcinoma histological types. Being a non-smoker was significantly associated with the prevalence of epidermal growth factor receptor mutations, but the prevalence of KRAS mutations was significantly associated with smoking.CONCLUSIONS:This study is the first to examine the prevalence of epidermal growth factor receptor and KRAS mutations in a Brazilian population sample with non-small cell lung cancer.

EGFRMutations in US Hispanic Versus Non-Hispanic White Patients With Lung Adenocarcinoma

“…COMMENT The frequency of the EGFR mutations in different populations is well documented. [16][17][18][19] For example, the mutation rate is higher in Asians and female nonsmokers. 20 However, the EGFR mutation rate in lung adenocarcinomas among the US Hispanic population has not been previously investigated to our knowledge.…”

“…Of note, the frequency of EGFR mutations in non-small cell carcinoma of the lung has been reported to be 33.2% in Latin American countries overall, which is similar to the Asian population. 18,19 The objective of this study was to determine the prevalence and type of EGFR mutations that occur in adenocarcinomas among the US Hispanic population.…”

Cancer Genes in Lung Cancer: Racial Disparities: Are There Any?

“…Interestingly, in 2 recent studies conducted in a Latin American cohort, the EGFR mutational frequency was significantly higher at 30.4% to 33.2%. 57,58 The EGFR mutational status seems also to vary between the primary lung tumor and the corresponding metastases. Often, the EGFR mutations would be present in the primary lung tumor but appear to be absent in the metastases.…”

Lung Adenocarcinoma Biomarker Incidence in Hispanic Versus Non-Hispanic White Patients

“…In the first of these, 15 650 non-small cell lung cancer specimens from Argentina, Colombia, Peru, and Mexico had a KRAS mutation frequency of 16.6% (n ¼ 108). In the second study, 16 KRAS mutation frequency among 206 non-small cell lung cancer specimens from Brazilian patients was 14.6% (n ¼ 30). Neither study included analysis of codons 59 and 61, and neither analyzed additional biomarkers implicated in nonsmall cell lung cancer.…”

“…5 Oncogenic mutations in EGFR have been found in non-small cell lung cancers in only 19% of African Americans 6-9 and 17% of non-Hispanic whites, 10,11 compared with 66% of Asians [10][11][12][13][14] and 33% of Hispanics. 15,16 Furthermore, EML4-ALK rearrangements are reported in approximately 6% to 7% of Asians with lung adenocarcinoma, compared with only 1% to 2% of non-Hispanic white patients. [17][18][19][20] Targeted therapies are available for both biomarkers, and standard of care requires testing all lung adenocarcinomas for EGFR mutations and EML4-ALK rearrangements.…”