Epidemiologic Features of NSCLC Gene Alterations in Hispanic Patients from Puerto Rico

Targeted therapy has changed the paradigm of advanced NSCLC management by improving the survival rate of patients carrying actionable gene alterations using specific inhibitors. The epidemiologic features of these alterations vary among races. Understanding the racial differences benefits drug development, clinical trial design, and health resource allocation. Compared to Caucasian and Asian populations, current knowledge on Hispanic patients is less and no data of Hispanic patients from Puerto Rico have been reported. We retrieved and analyzed the demographic, clinical, and molecular data of Hispanic NSCLC patients from Puerto Rico with molecular tests performed in the Genoptix Medical Laboratory in Carlsbad, CA, USA between 2011 and 2018. The majority of the NSCLC patients in our study had either adenocarcinoma (75.4%) or squamous cell carcinoma (15.1%). The incidence of EGFR mutations was 24%. They were more common in female and younger patients (<60 years). The deletion of Exon 19 and Exon 21 L858R comprised 55.1% and 31.0% of all EGFR mutations, respectively. The frequency of the T790M mutation was lower compared to that of Hispanic patients reported in the literature (0.5% vs. 2.1%). In addition, 18.7% of the patients were positive for KRAS mutations, which was at the high end of that reported in Hispanic patients. Other driver gene alterations, ALK, MET, RET, ROS1, KRAS, ERBB2, etc., demonstrated similar incidences, as well as gender and age distributions to those previously reported. The KRAS/TP53 and KRAS/STK11 co-mutations were of very low frequencies (3.6%), which could potentially affect the responsiveness to PD1/PD-L1 immunotherapy. Our study demonstrated that the prevalence of NSCLC gene alterations in Hispanic patients from Puerto Rico was comparable to the reported average prevalence in Latin American countries, supporting the intermediate NSCLC gene alteration rate of Hispanic patients between Asian and Caucasian patients. Novel information of the frequencies of KRAS mutation subtypes, driver gene alterations in ROS1, BRAF, and ERBB2, and passenger gene alterations including a rare case with the FGFR2-TACC2 translocation in Hispanic NSCLC patients from Puerto Rico were also described.