title: Clinicopathologic and molecular characteristics of lung adenocarcinoma arising in young patients.
abstract: Lung cancer rarely occurs in young patients. Recent studies have demonstrated that epidemiologic data are closely correlated to some molecular characteristics. We investigated the clinicopathologic characteristics of lung adenocarcinoma in young patients and evaluated immunohistochemically detected epidermal growth factor receptor (EGFR) mutation status and anaplastic lymphoma kinase (ALK) positivity. Among lung adenocarcinoma patients, 31 cases were of the ≤ 40 yr-old group and 261 cases of > 50 yr-old group. Young patients were more likely to be females (67.7% vs 40.2%), and nonsmokers (58.1% vs 45.2%) and more often had high TNM stage (stage IV was 80.6% vs 52.1%) and had a high rate of distant metastasis (51.6% vs 28.0%) compared with older patients. The signet ring cell feature was more common (25.8% vs 11.5%) and lepidic growth pattern was rarely present (3.2% vs 16.5%) in the adenocarcinoma of young patients. There was no significant survival difference between the two age groups. The rate of EGFR mutation status and ALK positivity did not show a statistical difference between two groups. In conclusion, lung adenocarcinoma of young patients demonstrates distinct pathologic features with frequent presence of a signet ring cell feature and rare occurrence of lepidic growth pattern. Further investigation for other genetic abnormalities would be needed.
authors.affiliation: Department of Pathology, Inha University School of Medicine, Incheon, Korea. luciado@inha.ac.kr
authors.forename: Lucia
authors.initials: L
authors.lastname: Kim
authors.forename: Kyu Ho
authors.initials: KH
authors.lastname: Kim
authors.forename: Yong Han
authors.initials: YH
authors.lastname: Yoon
authors.forename: Jeong Seon
authors.initials: JS
authors.lastname: Ryu
authors.forename: Suk Jin
authors.initials: SJ
authors.lastname: Choi
authors.forename: In Suh
authors.initials: IS
authors.lastname: Park
authors.forename: Jee Young
authors.initials: JY
authors.lastname: Han
authors.forename: Joon Mee
authors.initials: JM
authors.lastname: Kim
authors.forename: Young Chae
authors.initials: YC
authors.lastname: Chu
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D000077192:Adenocarcinoma of Lung; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000077548:Anaplastic Lymphoma Kinase; D066246:ErbB Receptors / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009367:Neoplasm Staging; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism; D012907:Smoking
chemical_list: C000626173:ALK protein, human; D000077548:Anaplastic Lymphoma Kinase; D066246:ErbB Receptors; D020794:Receptor Protein-Tyrosine Kinases