Correlation between TTF-1 expression and EGFR mutations in moroccan lung adenocarcinoma: A prospective six-year study

Lung cancer is the second most common malignancy worldwide and remains a leading cause of cancer-related mortality. Identifying predictive biomarkers is essential to improve personalized treatment. This prospective six-year study investigated the correlation between thyroid transcription factor-1 (TTF-1) expression and epidermal growth factor receptor (EGFR) mutations in Moroccan patients with lung adenocarcinoma.

Between 2017 and 2022, 234 patients with histologically confirmed lung adenocarcinoma were prospectively enrolled. TTF-1 expression was assessed by immunohistochemistry, and EGFR mutations were evaluated using molecular testing. Statistical analyses examined associations with clinicopathological parameters and overall survival.

TTF-1 expression was detected in 83.8 % of cases and was more frequent among females (85.5 %) and never-smokers (88.2 %). EGFR mutations were identified in 21.36 % of patients, with exon 19 deletions (15.38 %) and exon 21 mutations (4.27 %) being the most common. A strong association was observed between TTF-1 expression and EGFR mutations (p < 0.001), particularly exon 19 deletions (p = 0.009). No significant correlation was found with exon 21 mutations or rare/dual variants. Combined exon 19 and 21 mutations were also significantly associated with TTF-1 positivity (p = 0.001).

This study demonstrates a strong correlation between TTF-1 expression and common EGFR mutations, especially exon 19 deletions, in Moroccan patients with advanced lung adenocarcinoma. The association was most evident in never-smokers, supporting the role of TTF-1 and EGFR as complementary biomarkers in guiding diagnosis and treatment. Larger multicenter studies are warranted to further explore their prognostic value.