Surgically treated patients with stage I non-small cell lung cancer (NSCLC) are at risk for developing metastatic disease. 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.
We retrospectively examined 73 consecutive patients with resected stage I NSCLC, in whom preoperative chest CT scans and surgical specimens were available. Two chest radiologists reviewed chest CT scans for morphology of the lung cancer lesions while blinded to the pathology report. Immunohistochemical studies were preformed on the formalin-fixed, paraffin-embedded surgical samples of the primary tumors. Correlation between radiological findings and EGFR expression, time to recurrence and death was assessed.
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 (defined as > 10% membranous staining) 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).CONCLUSIONS: These data suggest that identification of a cavitary lesion is associated with adverse prognosis in stage I NSCLC. These patients may benefit from therapy with anti-EGFR targeted drugs.
Incorporation of radiological and molecular studies will establish a better patient clinical profile, which may identify stage I NSCLC patients at high risk for disease progression. A prospective study is planned.
A. Onn, None.