Implications of urinary basic fibroblast growth factor excretion in patients with urothelial carcinoma

1. Angiogenesis occurs in response to wounding, and is of vital importance for tumour growth and metastasis. Basic fibroblast growth factor, a well-known angiogenic factor, has been suggested to be a urine marker for urothelial carcinoma. However, the relevance of its detection has not been evaluated in a large number of patients. 2. Immunoassay of basic fibroblast growth factor was performed on urine samples from different aetiologies of urothelial disorder. Expression of basic fibroblast growth factor in the corresponding tumour was correlated with the urine level. 3. The excretion of basic fibroblast growth factor (ng/g creatinine) was significantly elevated in both inflammatory and neoplastic urological diseases compared with normal individuals (P<0.05), while it was normalized in tumour-free subjects (P<0.01). Receiver operating characteristic plotting revealed a sensitivity of 40% for tumour diagnosis at the cut-off point of 3.29 ng/g creatinine. The sensitivity of the test in predicting tumour recurrence was only 14%. The basic fibroblast growth factor level in urine showed a positive association with increasing age of cancer patients (P=0.02) and with tumour grading (P=0.05). However, no important relationship was observed regarding tumour stage, size, number, shape or degree of local inflammatory reaction (P>0.01). Pairwise analysis of the basic fibroblast growth factor level in urine and its expression in corresponding tumours did not reveal a conspicuous correlation (r=-0.097, P=0.43). 4. Our results suggested that estimation of urinary basic fibroblast growth factor cannot be satisfactory as a tumour marker. The measurement may represent one of the tissue responses to injury or the host-tumour interactions. A longitudinal study is required to elucidate the role of basic fibroblast growth factor in order to select the appropriate treatment strategy for urothelial carcinoma.