Non-BAC component but not epidermal growth factor receptor gene mutation is associated with poor outcomes in small adenocarcinoma of the lung.
OBJECTIVE
The purpose of this study was to identify risk factors for poor clinical outcome after surgical resection of small lung adenocarcinoma.


METHODS
Clinical records of 127 patients who had pathologic stage IA lung adenocarcinoma 20 mm or less and who had undergone a lobectomy with mediastinal lymph node dissection were reviewed. The percentage of non-bronchioloalveolar carcinoma (non-BAC) components quantified objectively, and epidermal growth factor receptor gene (EGFR) mutation determined by polymerase chain reaction-based assay were retrospectively linked with clinical data.


RESULTS
Based on the percentage of non-BAC component, 127 patients were classified as follows: 26 in group I, BAC, 46 in group II mixed subtype with >or= 50% BAC, 18 in group III, mixed subtype with under 50% BAC, and 37 in group IV, mixed subtype with all non-BAC components or a pure pattern of one of the non-BAC components. Groups I and II were considered to be a "low non-BAC component type" and groups III and IV were considered to be a "high non-BAC component type." EGFR mutations in exon19 and exon21 were observed in 64 patients (50.4%). In terms of recurrence, the high non-BAC component type was the only independent factor for recurrence (p = 0.029). Regarding survival, the high age (p = 0.028) and high non-BAC component type (p = 0.046) were independent risk factors for poor overall survival. They were also independent risk factors for poor disease-free survival (p = 0.025 and p = 0.027, respectively).


CONCLUSIONS
The high non-BAC component but not EGFR mutation status, is an independent risk factor for both recurrence and poor prognosis in patients with stage IA lung adenocarcinoma <or=20 mm.
Kobayashi
Naruyuki
N
Department of Cancer and Thoracic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
Toyooka
Shinichi
S
Ichimura
Kouichi
K
Soh
Junichi
J
Yamamoto
Hiromasa
H
Matsuo
Keitaro
K
Otani
Hiroki
H
Jida
Masaru
M
Kubo
Takafumi
T
Tsukuda
Kazunori
K
Kiura
Katsuyuki
K
Sano
Yoshifumi
Y
Date
Hiroshi
H
D000230:Adenocarcinoma / Q000235:genetics / Q000401:mortality / Q000473:pathology* / Q000556:secondary; D002282:Adenocarcinoma, Bronchiolo-Alveolar / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics / Q000401:mortality / Q000473:pathology* / Q000556:secondary; D005260:Female; D018773:Genes, erbB-1 / Q000235:genetics*; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009364:Neoplasm Recurrence, Local; D011379:Prognosis; D012307:Risk Factors