EGFR mutations in Latinos from the United States and Latin America.

Abstract

8070 Background: Activating mutations in the epidermal growth factor receptor gene (EGFR) confer hypersensitivity to EGFR tyrosine kinase inhibitors in patients with advanced non–small-cell lung cancer (NSCLC). Racial and ethnic differences in the frequency of such mutations have been previously described; however, there are limited and conflicting reports on its frequency in the Latino population. Methods: We collected samples from 642 patients with NSCLC from 7 institutions in the US and Latin-America. Activating EGFR mutation analysis of exons 18 through 21 was performed at 2 CLIA certified central laboratories. Statistical analyses were performed using Fisher’s exact test or Mehta’s modification to Fisher’s exact test to determine relationships among parameters. All p-values are two-tailed and reported without adjustment for multiple comparisons. Results: EGFR mutation analysis was successfully performed in 480 of 642 patients (75%) of which 90 (19%) were Latinos, 318 (66%) non-Latino Whites, 35 (7%) non-Latino Asians, 30 (6%) non-Latino Blacks and 7 (2%) from other race/ethnicities. EGFR mutations were found in 21 of 90 (23%) Latino patients and its frequency varied according to country of origin. The highest frequency was observed in Latinos from Peru (37%) followed by US (23%), Mexico (18%), Venezuela (10%) and Bolivia (8%). In Latinos never smokers and Latinos with adenocarcinoma histology, the frequency of EGFR mutations was 38% and 30% respectively. There was a significant difference in the frequency of EGFR mutations among the different racial/ethnic subgroups analyzed (p < 0.001) with non-Latino Asians having the highest frequency (57%) followed by Latinos (23%), non-Latino Whites (19%) and non-Latino Blacks (10%). However, there was no difference between Latinos (23%) and non-Latinos (22%) (p = 0.78) and Latinos and non-Latino Whites (p = 0.37). While patients from Peru had an overall higher frequency of mutations (37%) than all other Latinos (17%), such difference was not statistically significant (p = 0.06) and diminished greatly when smoking and adenocarcinoma histology subgroups were analyzed independently. Conclusions: There was no significant difference between the frequency of EGFR mutations in NSCLC in Latinos and non-Latinos.