RESUMO
BACKGROUND: Mutations in the epidermal growth factor receptor (EGFR) gene are commonly observed in non-small cell lung cancer (NSCLC), particularly in adenocarcinoma histology. The frequency of EGFR mutations is ethnicity-dependent, with a higher proportion reported in Asian populations than Caucasian populations. There is a lack of data on these mutations in north Africa. METHODS: Tumor specimens from Moroccan patients with NSCLC were collected from five pathology laboratories between November 2010 and December 2017 to determine frequency and types of EGFR mutations. Tumors were tested in a reference center for EGFR by polymerase chain reaction and sequencing of exons 18, 19, 20, and 21. RESULTS: A total of 334 patients were enrolled: 242 (72.5%) males and 92 females (27.5%). A total of 56.9% had a history of smoking. EGFR testing of the 334 lung adenocarcinoma samples demonstrated a wild-type EGFR in 261 (78.1%) and mutated EGFR in 73 (21.9%). Mutations were mainly detected in the exon 19 deletion (65.8%), followed by exon 21 L858 (17.8%) and other exon 21 codon mutations (5.5%) and exon 18 (6.8%), whereas primary mutations of exon 20 were less frequent (4.1%). In patients with advanced NSCLC, the detection of EGFR mutation was independently associated with sex (41.3% female vs 14.5% male; p < 0.001) and smoking status (34.8% nonsmokers vs 12.9% active smokers; p < 0.001). The mean age was significantly different between the two groups (p = 0.041). CONCLUSION: Our findings confirm the genetic heterogeneity of NSCLC worldwide, reporting frequency of EGFR mutations in Moroccan patients with NSCLC between those of Asian and Caucasian populations.
