Human Epidermal Growth Factor Receptor 2 Expression in Urothelial Carcinoma of the Renal Pelvis: Correlation with Clinicopathologic Parameters
Laleh Ehsani, Adeboye O Osunkoya. Emory University School of Medicine, Atlanta, GA
Background: The significance of Human Epidermal Growth Factor Receptor 2 (HER2) overexpression in breast cancer is well established, and these patients are subsequently treated with Trastuzumab. Although HER2 expression in urothelial carcinoma (UCA) of the urinary bladder has also been recently characterized, it has not been well studied in UCA of the renal pelvis. We investigated the relationship between HER2 overexpression in UCA of the renal pelvis with emphasis on correlation with clinicopathologic parameters.
Design: A search was made through the surgical pathology and consultation files of our institution for radical nephroureterectomy cases with UCA of the renal pelvis from 2008-2012 with available tissue blocks. Immunohistochemical stains for HER2 were performed. HER2 overexpression was defined as 3+ staining involving greater than 30% of tumor cells. Findings were correlated with clinicopathologic parameters including sex, stage, grade, and inverted growth pattern.
Results: Forty six cases were identified. HER2 overexpression was identified in 34/46 (74%) cases. Mean patient age with HER2 overexpression was 68 years (range: 42-87 years). There was a male predominance with 28/34 (82%) patients and 6/34 (18%) patients were female. High grade UCA was present in 32/34 (94%) cases and 2/34 (6%) cases had low grade UCA. Pathologic staging was as follows; 9/34 (26%) cases were pTa, 10/34 (29%) cases were pT1, 2/34 (6%) cases were pT2, 12/34 (35%) cases were pT3, and 1/34 (3%) cases was pT4. An inverted growth pattern was present in 23/46 (50%) cases. HER2 overexpression was present in 15/23 (65%) cases of UCA with an inverted growth pattern.
Conclusions: This is one of the first few studies to date to evaluate the expression of HER2 in UCA of the renal pelvis. Our study showed that HER2 overexpression is more common in male patients with high grade UCA, especially those with an inverted growth pattern. It is highly conceivable that patients with UCA of the renal pelvis may be further stratified based on HER2 overexpression, and may also be potential candidates for Trastuzumab therapy in the neoadjuvant or adjuvant setting.
Category: Genitourinary (including renal tumors)
Wednesday, March 6, 2013 9:30 AM
Poster Session V # 160, Wednesday Morning