Overexpression of laminin-5 γ2 chain and its prognostic significance in urothelial carcinoma of urinary bladder: association with expression of cyclooxygenase 2, epidermal growth factor, and human epidermal growth factor 2

Summary 

Laminin-5 (LN-5) and cyclooxygenase 2 (COX-2) play important roles in many kinds of cancers. Recently, it has been reported that epidermal growth factor (EGFR) and/or human epidermal growth factor 2 (HER2) expressions are associated with LN-5 and/or COX-2 expressions in a few carcinoma cell lines and human tumor tissue. LN-5, COX-2, EGFR, and HER2 expressions were examined immunohistochemically in 67 patients with urothelial carcinomas (UCs), and associations among these 4 biomarkers and clinicopathologic characteristics were investigated. Patients were classified into transurethral resection group and cystectomy group based on clinical end points, and prognostic significances of increased expressions were evaluated. Overexpression of LN-5, COX-2, EGFR, and HER2 was observed in 16 (23.9%), 34 (50.7%), 42 (62.7%), and 15 (22.4%) of 67 patients, respectively. LN-5 overexpression was associated high-grade (P = .002), invasive (pTa+1 versus pT2-4, P = .011), and nonpapillary (P = .027) UCs. Concerning EGFR and HER2, high-grade (EGFR, P = .0009; HER2, P = .003) and nonpapillary (EGFR, P = .016; HER2, P = .0002) UCs had a significantly higher overexpression rate. UCs penetrating basal membrane (pT1-4) showed significantly higher overexpression rates than pTa UCs on all biomarkers. In transurethral resection group, LN-5 overexpression could be proved as an independent prognostic parameter for intravesical recurrence (P = .007), whereas in cystectomy group, nodal involvement was an independent prognostic parameter for cause-specific survival (P = .025). The current study showed that the 4 biomarkers were associated with aggressive behaviors of UCs. Above all, LN-5 overexpression was considered to play an important role in intravesical recurrence of superficial UCs.

Abbreviations: UC, urothelial carcinoma, TCC, transitional cell carcinoma, TUR, transurethral resection, LN, laminin, COX, cyclooxygenase, EGFR, epidermal growth factor receptor, HER, human EGFR

Keywords: Urothelial carcinoma, Urinary bladder, Laminin-5, COX-2, erbB