URINARY AND TISSUE-LEVELS OF SCATTER FACTOR IN TRANSITIONAL-CELL CARCINOMA OF BLADDER

Purpose: We previously reported increased titers of scatter factor in urine of 20 patients with transitional cell carcinoma of the bladder c ompared to noncancer and cancer control groups. Scatter factor was als o found in bladder tumor extracts but the number of samples examined w as too small for detailed analysis. We report a followup study of larg er numbers of patients with transitional cell carcinoma and controls. Materials and Methods: The scatter factor content of urine samples and bladder tissue extracts was measured by enzyme-linked immunosorbent a ssay. Values were normalized per milligram creatinine or tissue protei n. Statistical analysis was performed using the Mann-Whitney U test or , for multiple comparisons, the Kruskal-Wallis H test. Results: Patien ts with transitional cell carcinoma of the bladder (52) had higher uri nary scatter factor titers than did 24 normal subjects (p < 0.001) or 14 with benign prostatic hypertrophy (p < 0.001), 49 with prostate can cer (p < 0.001) and 13 with other genitourinary tract cancers (p < 0.0 1). Transitional cell carcinoma cases with clinicopathological evidenc e of disease had greater urinary scatter factor levels than those with no evidence of disease at urine sampling (p < 0.01). However, patient s with transitional cell carcinomas in remission still had much greate r urinary scatter factors than did normal subjects (p < 0.001). In con trast, patients with active prostate cancer had urinary scatter factor levels similar to those in remission. Patients with muscle invasive o r high grade transitional cell carcinomas tended to have higher urinar y scatter factor levels than patients with nonmuscle invasive or low g rade tumors, respectively, but the differences were not significant. G reater levels of scatter factor were present in tissue extracts of mus cle invasive transitional cell carcinomas than in nonmuscle invasive t umors (p < 0.001) or nontumor tissue (p < 0.02). Invasion was more clo sely related to tissue scatter factor content than tumor grade, since high grade noninvasive transitional cell carcinomas had a scatter fact or content similar to that of low grade noninvasive transitional cell carcinomas. Conclusions: These studies suggest that scatter factor may be a marker of bladder cancer, urinary scatter factor titers tend to reflect disease activity and particularly high tissue titers of scatte r factor are found in muscle invasive cancers. A larger prospective st udy will be necessary to determine the clinical significance of elevat ed scatter factor titers in transitional cell carcinoma of the bladder .