P1.13-39 Epidermal Growth Factor Receptor Mutation Among Non-Small Cell Lung Cancer Patients in Trinidad and Tobago: Frequency and Trends

Abstract

Almost 70% of non-small cell lung cancer (NSCLC) patients present with unresectable disease and may benefit from chemotherapy or biologic therapy. Mutation testing now plays a vital role in their diagnostic work-up to determine which patients are more likely to receive benefit from biologic therapies. The rate of epidermal growth factor receptor (EGFR) mutations varies significantly across geographic regions and ethnicities, ranging from 13% to 64% in some areas. Several subgroups such as females, East Asians, never-smokers and those with adenocarcinoma histology have the highest reported rates of EGFR mutations. Regionally, the French West Indies reports an EGFR mutation rate of 36%. The frequency of the EGFR mutation among NSCLC patients in Trinidad and Tobago has not been previously reported in the literature. An observational, retrospective study was done using data obtained from the Lung Malignancy Unit (LMU) based at the Eric Williams Medical Sciences Complex (EWMSC). The EWMSC is the sole referral centre in Trinidad and Tobago for lung cancer and the LMU is responsible for co-ordinating clinical and educational services regarding lung cancer nationwide.The study population was limited to primary NSCLC patients presenting to the EWMSC from January 2014 to June 2017 whose biopsy samples were sent for EGFR testing and received either a positive or negative result. Patients’ clinical data was entered onto a spreadsheet and analysed using Microsoft Excel. The data for 94 patients with NSCLC were analysed. 68 of these patients were male, while 58 admitted to a history of smoking. EGFR mutations were present in 39.4% of this study population. Females demonstrated a significantly higher EGFR mutation rate than males (73.1% vs 26.5%, p < 0.0001). Smoking status was found to be significantly associated with differences in EGFR mutation status (p < 0.01). The mean age of presentation was similar despite of EGFR mutation status. Although a larger number of EGFR positive patients compared to EGFR negative patients had adenocarcinoma histology (97.3% vs. 89.5%), this was not found to be statistically significant (p = 0.29). The frequency of EGFR mutations in this study population (39.4%) was higher than most regions of the world but similar to that reported in the French Antilles. Sex and smoking status were significantly associated with differences in EGFR mutation status.