CA 19-9 as a serum marker in urothelial carcinoma

INTRODUCTION: CA 19-9 is a carbohydrate antigen related to Lewis A blood group antigen. It is well-known marker for pancreatic carcinoma and is being investigated for other malignancies including carcinoma bladder. We evaluated the role of serum CA 19-9 as a tumor marker and correlated its level with tumor stage and grade. MATERIALS AND METHODS: Seventy-five patients with histologically proven urothelial carcinoma were included in this study as case and 25 healthy volunteers as control. Preoperative 5 ml blood sample was collected. Serum level of CA 19-9 was measured using solid-phase enzyme-linked immunosorbent assay kit. The value of CA19-9 was expressed in U/ml and 37 U/ml was taken as cut-off upper value of normal. RESULTS: The range of CA19-9 in patients of urothelial carcinoma was 2 to 122 U/ml with a mean of 26.33±29.28, while in control, it was 8.48±5.01 U/ml (P<0.001). The sensitivity of CA19-9 was 29%. Serum CA19-9 was significantly elevated in invasive disease in comparison with superficial disease (47.17±34.43 vs 16.53±20.13) (P<0.001). Significantly high proportion of patients with invasive disease had value ≥37 U/ml (14/24 [58.3%] vs 8/51 [15.7%]) with P value <0.001. High proportion of high-grade tumor had raised value, 14/34 (41.25%); all patients with metastatic disease had value more than 37 U/ml. CONCLUSIONS: Serum CA19-9 is a marker of aggressiveness of urothelial carcinoma and is almost invariably raised in patients with metastatic disease. Thus, it may be used as a prognostic marker but not as a screening tool due to its low sensitivity.