Clinicopathologic Features and EGFR Mutation Status Using Antibodies Specific to the Two Major Form of Mutant EGFR in Lung Adenocarcinoma of Young Patients

초록

Background: According to our previous result, female, non-smokers, and histologic type of adenocarcinoma were more prevalent in the young age lung cancer patients compared with old patients. We evaluated the clinicopathologic differences and EGFR mutation status using mutation-specific antibodies between young and old patients with lung adenocarcinoma. Methods: We examined the medical records and pathologic slides of 32 cases (≤40 years old) and 265 cases (≥50 years old) of primary lung adenocarcinoma and detected EGFR mutations by immunohistochemistry. Results: In young age group, female (65.6% vs. 40.0%, p=0.008), and non-smokers predominance (69.2% vs. 46.7%, p=0.028), high TNM stage (stage IV was 81.3% vs. 51.3%, p=0.016), high rate of distant metastasis (50.0% vs. 27.9%, p=0.013), and presence of signet ring cell components (25.8% vs. 11.5%, p=0.025) were statistically different from old age group. However, tumor differentiation, predominant histologic type, bronchioloalveolar growth, and micropapillary feature were not different between two groups. EGFR mutation rate was detected in 22.6% and 26.9% of young and old age groups and showed no statistical difference (p=0.606). There was no survival difference between young and old age groups. Conclusions: lung adenocarcinoma of young patients demonstrated different clinicopathologic features such as female and nonsmoker predominance, high TNM stage and high rate of distance metastasis and presence of signet ring cell components but EGFR mutation rate was similar compared with old age groups. Key Words: Adenocarcinoma of lung, EGFR, Age group 127