Epidermal growth factor receptor (EGFR) expression in non-small cell lung carcinoma (NSCLC) and survival

Abstract

Introduction: EGFR is a key molecule in lung cancer initiation and progression. Studies on EGFR overexpression and poor survival in NSCLC have yielded controversial results. EGFR expression in Indian population and its association with survival is unknown. Objectives: To study EGFR expression in Lung cancer and its association with clinical and histological characteristics; treatment, performance status and six months survival. Methodology: Fifty cases with NSCLC [M:F=44:6, median age=65 years] with NSCLC were evaluated for EGFR expression by immunohistochemistry. Tumours exhibiting 1+ to 3+ stain were considered positive for EGFR expression. EGFR expression was further scored using H-scoring method with a threshold of 200. Patients were followed up for six months. Survival analysis was done using Cox Proportional hazard model. Results: 34 (68%) cases were EGFR positive. EGFR expression with IHC H-Score ≥ 200 was associated with poorer survival. There was 40% less hazard of death in patients with EGFR 200. [HR=0.40 (95%CI 0.16-1.01) p=0.0537] in all the lung cancer patients. Patients treated with Chemotherapy (Carboplatin-Paclitaxel & Gefitinib) showed a significant better survival compared to patients who did not receive chemotherapy [HR=2.73 (95%CI 1.03-7.25), p=0.004]. Higher Karnofsky [HR=5.02 (95%CI 1.51 -16.67) p=0.008] and lower ECOG scores were significantly associated with better survival [HR=0.26 (95%CI 0.09-0.69) p=0.006]. Conclusion: EGFR is an important prognostic marker in NSCLC. Overexpression (H-score>200) was associated with poorer prognosis. However EGFR expression is associated with better 6 month survival after Chemotherapy.