Tumor Cavitation is Associated with Epidermal Growth Factor Expression and Is a Predictor of Poor Outcome in Patients with Stage I Non-Small Cell Lung Cancer

Abstract: HTML Purpose: Surgically treated patients with stage I non-small cell lung cancer (NSCLC) are at risk for developing metastatic disease. Future therapy will aim to target tumor specific receptors. To identify potential treatable factors of disease progression, we analyzed tumor radiographic characteristics in stage I NSCLC and correlated them with the expression of epidermal growth factor receptor (EGFR), which plays a significant role in cancer progression and angiogenesis. Methods and Materials: We retrospectively examined 73 patients with newly diagnosed completely resected stage I NSCLC in whom preoperative chest CT scans and tissue samples from resected tumors were available. Two experienced chest radiologists reviewed chest CT scans for morphology of the lung cancer while blinded to the clinical data and pathology report. These were evaluated for size, presence of calcifications, contour, margin, and presence of ground glass opacities, cavitation, and lobar location. Immunohistochemical studies were preformed on the formalin-fixed, paraffin-embedded surgical samples of the primary tumor. Using the chi square test, correlation between radiological findings to EGFR expression, time to recurrence and death was assessed. Results: Median follow-up was 55.7 months (range 0-157 months), and the overall median survival was 75.5 months. An excellent correlation was found between tumor size as assessed by radiologists and as measured in pathology report (p<0.001, Pearson correlation 0.913). EGFR was overexpressed in 48 tumors (66%). EGFR overexpressing tumors were more commonly found in squamous cell cancer (SCC) than in adenocarcinoma (ACA) (p=0.028) and more in T2 than T1 tumors (P=0.001). Cavitation was found in 16 tumors (22%). Cavitary lesions were more commonly found in SCC than ACA (p=0.013), and were associated with EGFR overexpression (p=0.012). Cavitary lesions were significantly associated with a higher recurrence rate (p=0.01) and a shorter overall survival (p=0.0081). Using Cox mutlivariate analysis to adjust for tumor size, histology and EGFR status we found that these factors did not change adverse prognosis associated with cavitation. Conclusion: These data suggest that identification of a cavitary lesion is associated with adverse prognosis in stage I NSCLC. Incorporation of radiological and molecular studies could establish a better patient clinical profile, which may identify stage I NSCLC patients at high risk for disease progression who may benefit from anti EGFR therapy. A prospective study is warranted. Questions about this event email: emarom@di.mdacc.tmc.edu

J02-756

Tumor Cavitation is Associated with Epidermal Growth Factor Expression and Is a Predictor of Poor Outcome in Patients with Stage I Non-Small Cell Lung Cancer