Urine laminin P1 assessment discriminates between invasive and noninvasive urothelial cell carcinoma of the bladder.

In a cross-section study the levels of urine laminin P1 expressed as a laminin P1:creatinine ratio were determined in 25 patients with superficial (noninvasive) transitional cell carcinoma (TCC) of the bladder, 12 patients with invasive TCC, 15 patients with inflammatory bladder diseases and 50 healthy controls. The mean of laminin P1:creatinine ratios in invasive TCC patients (4.83 +/- 3.05 U/mol creatinine) significantly differed from those of superficial TCC (2.60 +/- 1.07 U/mol creatinine), inflammatory bladder disorders (2.38 +/- 1.74 U/mol creatinine) and controls (2.47 +/- 0.86 U/mol creatinine) (p < 0.03). At the individual patient level 7 out of 12 patients with invasive TCC, but only 1 out of 25 patients with superficial TCC, showed laminin P1 urine levels above the normal range (0.75-4.18 U/mol creatinine), thus giving a 58% sensitivity and a 96% specificity of laminin P1 urine assessment in the discrimination between noninvasive and invasive disease. Given a 20-24% prior chance of invasive disease at initial diagnosis detection of elevated urine laminin P1 in TCC patients raises the posttest chance of invasive disease to 87.5%.