Tumor cavitation in stage I non-small cell lung cancer: epidermal growth factor receptor expression and prediction of poor outcome

Abstract

Purpose: To retrospectively identify radiographic characteristics of stage I non-small cell lung cancer (NSCLC) that may correlate with epidermal growth factor receptor (EGFR) or HER2 expression or with prognosis.

Materials and methods: This study was approved by the institutional review board, with waiver of informed consent, and was in compliance with HIPAA regulations. Findings of chest computed tomography (CT) were retrospectively evaluated in 72 patients who underwent resection of pathologic stage I NSCLC; tumor diameter, presence of calcifications, type of contour, type of margins, attenuation of the nodule, presence of a halo, presence of cavitation, and tumor location were documented. Immunohistochemical studies were performed in surgical specimens. Imaging and molecular data were correlated with patient outcome. Cox proportional hazards regression models were used to correlate biologic and radiographic variates with clinical outcome.

Results: There were 38 men (53%) and 34 women (47%) (median age, 65.5 years). Median follow-up was 56.3 months; median overall survival, 76.3 months. A strong correlation was found between tumor diameter measured by radiologists and that measured by pathologists (P < .001; Pearson correlation coefficient, 0.81). EGFR overexpression was found in 48 (67%) tumors; significantly more was found in squamous cell carcinomas than was found in adenocarcinomas (P = .028), and more was found in T2 tumors than was found in T1 tumors (P = .001). HER2 overexpression was found in 13 (18%) tumors; cavitation, in 16 (22%) tumors. Cavitary lesions were significantly more common in squamous cell carcinomas than were in adenocarcinomas (P = .013) and in EGFR-overexpressing tumors (P = .012) than in tumors that did not overexpress EGFR. Cavitary lesions were significantly associated with shorter disease-free survival time (P = .01) and shorter overall survival time (P < .007).

Conclusion: Patients who have stage I NSCLC with cavitary lesions have an adverse prognosis and are likely to have tumor EGFR overexpression.