High incidence of EGFR mutations in pneumonic-type non-small cell lung cancer

To retrospectively identify computed tomography (CT) features that correlate with epidermal growth factor receptor (EGFR) mutation in surgically resected pneumonic-type lung cancer (P-LC). A total of 953 consecutive patients with surgically resected lung cancer in the First Affiliated Hospital of Guangzhou Medical University from August 2011 to August 2013 were studied. The CT manifestations were reevaluated independently by 2 radiologists. The presence of pneumonic-type consolidation with pathological confirmed non-small lung cancer (NSCLC) was defined as P-LC. EGFR mutation was determined by direct DNA sequencing or amplification refractory mutation system-PCR. EGFR mutation rates as well as clinical and pathological manifestations between P-LC and control lung cancer patients were compared. P-LC was diagnosed in 85 patients. Among these patients, 82 were adenocarcinoma (including 78 cases of invasive adenocarcinoma and 4 cases of microinvasive adenocarcinoma), 2 were squamous carcinoma and 1 was other type. P-LC occurred more frequently in female (58.8% vs 37.1%, P < 0.01), nonsmoking (76.5% vs 56.5%, P = 0.001) and adenocarcinoma (58.8% vs 37.1%, P < 0.01) patients. Moreover, EGFR mutations were found in 39 of 52 P-LC patients (75%) and 263 of 542 non-P-LC NSCLC patients (48.5%). However, no difference was found on the mutation sites of EGFR. Histological type, sex, and radiological manifestations (P-LC vs non-P-LC) but not smoking or sequencing method can be served as the independent predictor of EGFR mutations. P-LC patients showed a significant higher incidence of EGFR mutations, which was independent of sex, histological type, and smoking history. The patients with imaging manifestation of pneumonic-type consolidation are highly suggested to perform EGFR mutation analysis to guide the sequential treatment.