MET expression plays differing roles in non-small-cell lung cancer patients with or without EGFR mutation.
BACKGROUND
Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors and Met inhibitors have enabled progress in the management of advanced non-small-cell lung cancer (NSCLC). However, the clinical benefits of these agents are not uniform across the NSCLC spectrum. Thus, we evaluated the prognostic effect of mesenchymal-epithelial transition (MET) expression in Asian NSCLC patients with or without EGFR mutation.


METHODS
Frozen tumor tissues were collected from 92 patients with surgical resection and 10 with lymph node biopsy. Mutations in exons 18-21 in the EGFR-tyrosine kinase domain and MET expression were analyzed by using sequencing and immunohistochemistry, respectively.


RESULTS
The MET overexpression rate was 51% in NSCLC patients. MET-positive patients had poorer overall survival than MET-negative patients (29.8 versus 69.1 months, χ = 7.420, p = 0.006) in patients with wild-type EGFR. However, no statistically significant difference was found in EGFR mutant patients (35.0 versus 35.9 months, χ = 0.114, p = 0.735). Multivariate analysis showed that stage, MET expression, and sex were independent prognostic factors in patients with wild-type EGFR (χ = 32.896, p < 0.001).


CONCLUSIONS
These results suggest that MET expression has different prognostic significance in patients with differing EGFR mutation status. Whether MET inhibitors should be given early to NSCLC patients with EGFR wild-type needs further investigation.
Guangdong Lung Cancer Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.
Ling
L
Huang
She-Juan
SJ
An
Zhi-Hong
ZH
Chen
Jian
J
Su
Hong-Hong
HH
Yan
Yi-Long
YL
Wu
D000328:Adult; D000368:Aged; D044466:Asian People / Q000235:genetics; D002289:Carcinoma, Non-Small-Cell Lung / Q000737:chemistry* / Q000235:genetics* / Q000473:pathology; D002681:China; D004252:DNA Mutational Analysis; D066246:ErbB Receptors / Q000235:genetics*; D005091:Exons; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000737:chemistry* / Q000235:genetics* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011379:Prognosis; D019859:Proto-Oncogene Proteins c-met / Q000032:analysis*; D012189:Retrospective Studies; D012737:Sex Factors; D015996:Survival Rate
C512478:EGFR protein, human; D066246:ErbB Receptors; D019859:Proto-Oncogene Proteins c-met