Clinical Significance of Detecting Somatic Gene Mutations in Surgically Resected Adenosquamous Cell Carcinoma of the Lung in Japanese Patients.
BACKGROUND
Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) and echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) inhibitors are effective and useful agents for treating patients who harbor EGFR-TKI-sensitive mutations or EML4-ALK rearrangement. Therefore, the importance of determining the presence of these somatic mutations when treating lung adenocarcinomas is widely accepted. However, genetic mutations are rarely evaluated in patients with adenosquamous cell carcinoma of the lung, a relatively infrequent histologic type of lung cancer, because of limited knowledge and the unclear value of assessing these oncogenic mutations in these patients. Therefore, we investigated the clinical implications of somatic mutations in surgically resected adenosquamous cell carcinoma of the lung in Japanese patients.


METHODS
We retrospectively analyzed 32 patients with adenosquamous cell carcinoma of the lung who underwent surgical resection at two institutes in Japan. EGFR mutations and EML4-ALK rearrangement were assessed in all of the patients.


RESULTS
Overall, 7 (21.9 %) of 32 patients had EGFR mutations: three patients had an exon 19 deletion and 4 had an exon 21, L858R mutation. There were no T790 M mutations. The median relapse-free survival was 766 days and the median overall survival was 1,152 days in the total cohort. Relapse-free survival and overall survival were not significantly different between patients with or without EGFR mutations.


CONCLUSIONS
Detecting EGFR mutations in patients with adenosquamous cell carcinoma is clinically important, especially in patients with disease recurrence because EGFR-TKIs may be effective in this histologic type of lung cancer.
Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, yo-suke@surg2.med.kyushu-u.ac.jp.
Yosuke
Y
Morodomi
Tatsuro
T
Okamoto
Mitsuhiro
M
Takenoyama
Kazuki
K
Takada
Masakazu
M
Katsura
Yuzo
Y
Suzuki
Takatoshi
T
Fujishita
Hirokazu
H
Kitahara
Shinichiro
S
Shimamatsu
Mikihiro
M
Kohno
Tetsuzo
T
Tagawa
Shinji
S
Okano
Kenichi
K
Taguchi
Yukito
Y
Ichinose
Yoshihiko
Y
Maehara
D000368:Aged; D000369:Aged, 80 and over; D018196:Carcinoma, Adenosquamous / Q000235:genetics* / Q000601:surgery; D018572:Disease-Free Survival; D066246:ErbB Receptors / Q000235:genetics*; D005091:Exons; D005260:Female; D015321:Gene Rearrangement; D006801:Humans; D007564:Japan; D008175:Lung Neoplasms / Q000235:genetics* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D012189:Retrospective Studies; D017384:Sequence Deletion; D015996:Survival Rate
C522504:EML4-ALK fusion protein, human; D015514:Oncogene Proteins, Fusion; D066246:ErbB Receptors