Comparison of growth pattern in lung adenocarcinoma with L858R and 19DEL EGFR mutation.

PURPOSE: Mathematical comparisons of lung adenocarcinoma (LUAD) with epidermal growth factor receptor (EGFR) mutations of L858R and 19DEL. METHODS: A total of 1,980 surgically resected LUAD cases were analyzed, comprising 1,195 ground glass opacity LUAD (GGO-LUAD) and 785 pure solid lung adenocarcinomas (pSD-LUAD). LUAD cases were grouped based on EGFR mutation status. Correlations between tumor size (x) and frequency ratio (y) were analyzed using exponential equations. RESULTS: Multivariate logistic regression analysis showed that the 19DEL mutation was more frequently observed in younger individuals (OR: 1.60, 95% CI: 1.29-1.99, p < 0.0001) and high-grade tumors (OR: 1.46, 95% CI: 1.01-2.11, p = 0.004). Equations were fitted as follows: y = e-0.046 + 0.48 × (x ≤ 2.5 cm, p = 0.0016) (1), y = e-2.09 + 0.37 × (x ≤ 4 cm, p < 0.0001) (2), y = e-1.65 + 0.38 × (x ≤ 4 cm, p = 0.0001) (3). CONCLUSION: pGGO-LUAD with L858R EGFR mutations grew more rapidly than those with 19DEL mutations, but the solidification rate of L858R-mutated GGO-LUAD was lower compared to 19DEL-mutated GGO-LUAD.