Immunohistochemichal expression of biomarkers: a comparative study between diagnostic bronchial biopsies and surgical specimens of non-small-cell lung cancer.
BACKGROUND
The increasing use of biomarkers as molecular determinants of responsiveness to conventional chemotherapy or molecular targeted therapy has raised the question of the reliability and reproducibility of their evaluation in bronchial biopsies as compared with corresponding resected surgical specimens.


METHODS
Immunohistochemical expression of five markers related to signal transduction [epidermal growth factor receptor (EGFR), phospho-Akt], cell proliferation (Ki-67), DNA repair [excision repair cross-complementing (ERCC)1] and cellular 'immortality' [human telomerase catalytic component (hTERT)], was assessed in 41 patients with operable non-small-cell lung cancer in both bronchial biopsies and whole surgical specimens.


RESULTS
High correlation coefficients were observed between the expression of ERCC1, hTERT and Ki-67 in the biopsies and the surgical specimens [0.83 (P < 0.0001); 0.55 (P < 0.001) and 0.64 (P < 0.0001), respectively]. On the other hand, biomarker expression in biopsy was less correlated with the expression in the whole tissue sample for the markers of signal response and transduction [0.24 (P = 0.17) and 0.29 (P = 0.09) for EGFR and phospho-Akt, respectively].


CONCLUSIONS
Our results indicate a lack of association in the expression of important biomarkers between lung biopsies and corresponding resected tumors, with discordance rates ranging between 9% and 41%. Although these results need to be further validated in larger cohorts, they indicate that the evaluation of the expression of biomarkers in bronchial biopsies can be misleading.
Taillade
L
L
Department of Medicine, Institut Gustave Roussy, Villejuif, France.
Penault-Llorca
F
F
Boulet
T
T
Fouret
P
P
Michiels
S
S
Taranchon
E
E
Mountzios
G
G
Validire
P
P
Domont
J
J
Girard
P
P
Grunenwald
D
D
Le Chevalier
T
T
Soria
J-C
JC
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000032:analysis*; D014408:Biomarkers, Tumor / Q000032:analysis*; D001980:Bronchi / Q000473:pathology*; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology* / Q000601:surgery*; D004268:DNA-Binding Proteins / Q000032:analysis; D004720:Endonucleases / Q000032:analysis; D066246:ErbB Receptors / Q000032:analysis; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000032:analysis; D008175:Lung Neoplasms / Q000473:pathology* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019098:Telomerase / Q000032:analysis
D015415:Biomarkers; D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; D019394:Ki-67 Antigen; D066246:ErbB Receptors; D019098:Telomerase; C071447:ERCC1 protein, human; D004720:Endonucleases