Human epidermal growth factor receptor 2 expression in urothelial carcinoma of the renal pelvis: correlation with clinicopathologic parameters.

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 of the urinary bladder has also been recently characterized, it has not been well studied in urothelial carcinoma of the renal pelvis. We investigated the relationship between HER2 overexpression in urothelial carcinoma of the renal pelvis and clinicopathologic parameters. Forty six cases were identified. HER2 overexpression was present 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. High grade urothelial carcinoma was present in 32/34 (94%) cases and 2/34 (6%) cases had low grade urothelial carcinoma. 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 urothelial carcinoma with an inverted growth pattern. Our study showed that HER2 overexpression is more common in male patients with high grade urothelial carcinoma, especially those with an inverted growth pattern. It is highly conceivable that patients with urothelial carcinoma 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.