Racial disparity of epidermal growth factor receptor expression in prostate cancer.
OBJECTIVE
The epidermal growth factor receptor (EGFR) plays a critical role in prostate cancer (PC) signal transduction and is the target of a novel class of anticancer agents. Despite recent reports of interethnic variation in response to EGFR inhibitors, limited information exists regarding differences in expression of EGFR in PC patients. This has therapeutic relevance because a better understanding of the molecular basis underlying the ethnic variability will help in the design of individualized treatment regimens using EGFR inhibitors.


METHODS
We investigated EGFR expression in a well-characterized cohort of PC patients to determine the association between EGFR expression and race. Tumor tissues from 202 radical prostatectomies performed between 1990 and 2000 at the Veterans Administration Medical Center (New York, NY) were studied (142 African Americans, 60 whites; median age, 67 years; stage T2, n = 130; stage > or = T3, n = 72; Gleason score < 7, n = 110; Gleason score > or = 7, n = 92). Membrane-specific EGFR expression was evaluated immunohistochemically.


RESULTS
EGFR overexpression, defined as complete membrane staining in more than 10% of tumor cells, was observed in 75 of 202 patients (37%). There was a significant association between EGFR overexpression and African American race (P = .0006), higher pretreatment prostate-specific antigen (PSA; P = .02), and stage (P = .02), but not Gleason score (P = .33). The association between African American race and EGFR overexpression remained significant in a multivariate model after controlling for grade, stage, and pretreatment PSA simultaneously (P = .003).


CONCLUSIONS
Our data demonstrate that race contributes significantly to variability of EGFR expression in prostate cancer. Racial background may have an impact on the design of clinical trials to test the efficacy of anti-EGFR agents.
Shuch
Brian
B
Department of Urology, New York University Cancer Institute, New York, NY, USA.
Mikhail
Maryann
M
Satagopan
Jaya
J
Lee
Peng
P
Yee
Herman
H
Chang
Caroline
C
Cordon-Cardo
Carlos
C
Taneja
Samir S
SS
Osman
Iman
I
D000328:Adult; D001741:Black or African American / Q000235:genetics*; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D001707:Biopsy, Needle; D015331:Cohort Studies; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D011336:Probability; D011379:Prognosis; D011468:Prostatectomy / Q000379:methods; D011471:Prostatic Neoplasms / Q000208:ethnology* / Q000235:genetics / Q000601:surgery; D012189:Retrospective Studies; D016019:Survival Analysis; D044465:White People / Q000235:genetics*
D014408:Biomarkers, Tumor; D066246:ErbB Receptors