As the editorial comment points out, the gap between our knowledge of which markers are expressed on tumor cells and which of these markers will provide a successful therapeutic target has become increasingly apparent. Furthermore, the complexities of signaling pathways have complicated attempts to target receptors identified on tumor tissue: for example, K-ras mutations affect response to epidermal growth factor receptor (EGFR)–targeted therapy. In penile cancer, with nearly ubiquitous EGFR expression and low incidence of K-ras mutation, we might expect some response to EGFR-targeted therapy but will need to interrogate the pathway more comprehensively to understand why some patients benefit and others do not. In addition to biologic questions, there are important, if somewhat mundane clinical questions, that will be hard to answer without collaboration between centers seeing a fair volume of penile cancer, given the small number of cases. Whether EGFR-targeted therapy will be sufficient on its own, which would provide a low-toxicity option, or will be more effective in combination with chemotherapy will be an important question as clinical trials are designed. And, whether we can use oral EGFR-inhibitors rather than the more cumbersome weekly intravenous antibodies is a question of interest to patients. We have been fortunate to treat some of our patients with penile cancer with EGFR-targeted therapy; in addition to the cases presented here, we have seen many other patients benefit. However, without formal prospective data this “off-label” treatment might become increasingly difficult as society struggles to contain the cost of cancer treatment. Referral of patients with penile cancer for clinical trials will be critical to ensure that in the future, access to potentially effective targeted therapy does not become restricted to patients with penile cancer who can afford such treatments.
Published online: November 13, 2013
© 2014 Elsevier Inc. Published by Elsevier Inc. All rights reserved.
- Editorial Comment
UrologyVol. 83Issue 1
Epidermal growth factor receptor (EGFR) is expressed in nonsmall cell lung cancer, head and neck squamous cell carcinoma, colorectal cancer, and breast cancer. In each of these diseases, there are EGFR inhibitors that are approved for these conditions. EGFR is expressed in squamous cell penile cancer.1-3 The question: is it potentially useful in patients with squamous cell penile cancer? There are important parameters whether a target for treatment is important or not. Is the target over expressed, could it be inhibited, is it the predominant target, is it an important factor for growth for this cancer, and could it be given safely.