Objectives: To analyse the prognostic significance of insulin-like growth factor binding protein-2 (IGFBP-2) and IGFBP-3 in patients having a radical cystectomy for invasive bladder cancer.
Patients and methods: Tissue samples of invasive bladder cancer were obtained from 97 patients who had radical cystectomy. The expression of IGFBP-2 and IGFBP-3 mRNAs in these samples was measured by real-time reverse transcription-polymerase chain reaction (RT-PCR), and the findings analysed in relation to clinicopathological factors.
Results: During the observation period, 31 patients (group A) developed disease recurrence, while the remaining 66 (group B) had no evidence of recurrence. The expression level of IGFBP-2 mRNA was significantly higher in group A than in B, while IGFBP-3 mRNA expression was significantly lower in group A than in B, and there was a significant difference in the relative expression ratio of IGFBP-2 to IGFBP-3 (BP-2/BP-3 ratio) between the groups. Recurrence-free survival in patients with an elevated BP-2/BP-3 ratio was significantly lower than in those with a normal ratio. Multivariate analysis indicated that an elevated BP-2/BP-3 ratio, but not IGFBP-2 and IGFBP-3 mRNA levels, was an independent predictor of disease recurrence.
Conclusions: These findings suggest that the BP-2/BP-3 ratio measured by real-time RT-PCR could be useful for predicting disease recurrence in patients who have had a radical cystectomy for invasive bladder cancer.