OBJECTIVE - To evaluate insulin-like growth factor-1 receptor (IGF1R) expression in penile cancer and its association with oncologic outcomes.
METHODS - Tissue microarrays were constructed from 53 patients treated at our institution.
Expression of IGF1R was evaluated using a Her2-like scoring system. Overexpression was defined as 1+ or greater membranous staining. Association of IGF1R expression with pathologic features was assessed with comparative statistics, and association with local recurrence, progression to nodal or distance metastases or death was assessed with Kaplan-Meier survival analysis and Cox proportional hazard regression models.
RESULTS - Overall, IGF1R overexpression was seen in 33 (62%) cases. With a median follow-up of 27.8 months, IGF1R overexpression was associated with inferior progression-free survival (PFS) (p=0.003). In a multivariable model controlling for grade, T stage, PNI and lymphovascular invasion, IGF1R expression was independently associated with disease progression (HR 2.3, 95%CI 1.1-5.1, p = 0.03. Comparing patients without IGF1R over-expression to those with over-expression, 5 year PFS was 94.1% vs 45.8%.
CONCLUSIONS - IGF1R over-expression was associated with inferior PFS in penile cancer. Drugs that target IGF1R and downstream messengers may have a therapeutic benefit in patients that exhibit IGF1R over-expression.
Urology. 2016 Feb 18 [Epub ahead of print]
Mark W Ball, Stephania M Bezerra, Alcides Chaux, Sheila F Faraj, Nilda Gonzalez-Roibon, Enrico Munari, Rajni Sharma, Trinity J Bivalacqua, George J Netto, Arthur L Burnett
The James Buchanan Brady Urological Institute & Department of Urology, The Johns Hopkins University School of Medicine. Department of Pathology, The Johns Hopkins University School of Medicine., Norte University, Office of Scientific Research, Asunción, Paraguay., Department of Pathology, The Johns Hopkins University School of Medicine., Department of Pathology, The Johns Hopkins University School of Medicine., Department of Pathology, The Johns Hopkins University School of Medicine., Department of Pathology, The Johns Hopkins University School of Medicine., The James Buchanan Brady Urological Institute & Department of Urology, The Johns Hopkins University School of Medicine., Department of Pathology, The Johns Hopkins University School of Medicine; The James Buchanan Brady Urological Institute & Department of Urology, The Johns Hopkins University School of Medicine., The James Buchanan Brady Urological Institute & Department of Urology, The Johns Hopkins University School of Medicine.