title: Epidermal growth factor receptor mutation status and clinicopathological features of combined small cell carcinoma with adenocarcinoma of the lung.
abstract: In lung cancer, somatic mutations of epidermal growth factor receptor (EGFR) are concentrated in exons 18-21, especially in adenocarcinoma (Ad), but these mutations have rarely been reported in small cell lung carcinoma (SCLC). Combined SCLC is rare, and the EGFR mutation status and its relationship to the clinicopathological features of this tumor type have not yet been elucidated. We retrospectively studied six patients with combined SCLC with Ad components among 64 consecutive patients who underwent resection of SCLC. The clinicopathological features of each patient were reviewed, especially for the distribution pattern of the Ad component and lymph node metastases. EGFR mutations were screened by high-resolution melting analysis in each case, and were confirmed by sequencing of each mutation in the microdissected SCLC or Ad components. Regarding EGFR, no specific mutation was detected in five of the six patients, whereas one female patient who had never smoked had a missense mutation. In this case, both the SCLC and Ad components shared the same mutation in exon 21 (L858R). We identified a patient with combined SCLC with Ad sharing an identical EGFR mutation in both the SCLC and Ad components. In addition to the clinicopathological characteristics of this rare histological type of lung cancer, these findings provide useful information for better understanding the biology, natural history and clinical management of SCLC.
authors.affiliation: Clinical Laboratory Division, National Cancer Center Hospital, 5-1-1 Tsukuji, Chuo-ku, Tokyo, Japan.
authors.forename: Tomoya
authors.initials: T
authors.lastname: Fukui
authors.forename: Koji
authors.initials: K
authors.lastname: Tsuta
authors.forename: Koh
authors.initials: K
authors.lastname: Furuta
authors.forename: Shun-Ichi
authors.initials: S
authors.lastname: Watanabe
authors.forename: Hisao
authors.initials: H
authors.lastname: Asamura
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Ohe
authors.forename: Akiko Miyagi
authors.initials: AM
authors.lastname: Maeshima
authors.forename: Tatsuhiro
authors.initials: T
authors.lastname: Shibata
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Masuda
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Matsuno
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D000368:Aged; D018288:Carcinoma, Small Cell / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D004252:DNA Mutational Analysis; D066246:ErbB Receptors / Q000235:genetics*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009367:Neoplasm Staging