The value of urinary fibrin/fibrinogen degradation products as tumor markers in urothelial carcinoma

Urine based markers of urological malignancy

PURPOSE

A number of urine based markers have been and are being investigated for the diagnosis and prognostication of urological conditions. A majority of these markers have been evaluated in urological neoplasms, particularly bladder cancer. The diagnosis of bladder cancer currently relies on identifying malignant cells in the urine and subsequently visualizing the tumor on cystoscopy. This diagnosis is further confirmed by transurethral resection or biopsy. While urine cytology is specific, it is not sensitive, especially for detecting low grade disease. This characteristic has prompted the search for more accurate markers of bladder cancer. In this review we critically examine the results of studies evaluating various markers for bladder cancer.

MATERIALS AND METHODS

The published literature on urine based markers for all urological diseases, particularly bladder cancer, was identified using a MEDLINE search and critically analyzed. The sensitivity, specificity, positive and negative predictive values of the various markers were compared. The benefit of using combined markers rather than a single marker was also analyzed from published reports.

RESULTS

Most published literature on urine based markers for urological malignancies involve such markers for diagnosing and prognosticating bladder cancer. Hence, we focused mainly on urine based markers in bladder cancer. Most markers appear to have an advantage over urine cytology in terms of sensitivity, especially for detecting low grade, superficial tumors. However, most markers tend to be less specific than cytology, yielding more false-positive results. This scenario is more common in patients with concurrent bladder inflammation or other benign bladder conditions. However, there is reason to be optimistic about several new markers that appear to provide better specificity. Few urine based markers have been identified and investigated in other urological tumors.

CONCLUSIONS

Detecting bladder cancer using diagnostic markers still presents a challenge. A number of new markers are currently available that appear to be significantly more accurate than cytology. However, further studies involving a larger number of patients are required to determine their accuracy and widespread applicability for diagnosing bladder cancer. Urine based markers do not appear to have a significant role in the diagnosis or prognosis of other urological malignancies, such as prostate, kidney or testicular cancer.

The utility of fibrin/fibrinogen degradation products in superficial bladder cancer

Fibrin/fibrinogen degradation products are either absent or present at exceedingly low levels in the urine of healthy persons. Although various nonspecific inflammatory conditions of the urinary tract can result in detectable amounts of FDP in the urine, the presence of FDP is far more prevalent in urine from patients with bladder cancer. Urinary FDP levels tend to be higher in patients with tumors of increasing grade and stage. This correlation results in improved sensitivity in detecting more aggressive tumors. Current monoclonal antibody immunoassays are simple, rapid, and inexpensive, and can be performed on urine samples in the clinical setting. The overall accuracy of these immunoassays ranges from 75% to 80% (Table 1), suggesting that the urine FDP test should not be used alone for the surveillance of superficial bladder cancer. When assays for urine FDP are combined with urine cytology, the sensitivity for detecting tumors is improved. Prospective data are needed to determine whether using these tests in combination can safely permit a reduced frequency of endoscopic surveillance.

Bladder tumor markers: need, nature and application. 2. Tumor and tumor-associated antigens

Despite the diversity of the available markers, none is truly specific to transitional epithelium, let alone its tumors. Some of the markers used, such as hCG and CEA, are far better known in other fields and seem to be expressed in only a minority of urothelial tumors. The majority of the available markers are tumor associated and should perhaps be considered as by-products of the process of malignancy in the urinary tract. Newer tests which are simple, rapid and easy to use have a practical advantage. These are currently the Bard BTA, BTA Stat and Aura-Tek FDP tests. So far, these markers have achieved only an arguable and marginal role in daily clinical practice, challenging the role of cytology and helping decide the type of cystoscopy. A more substantial role awaits a test with higher and more consistent sensitivity and specificity, together with the capability to provide independent diagnostic and/or prognostic information. In this part of the review we examine the literature view of the above-mentioned tests, as well as other new and some older tests such as blood group-related antigens, Lewis antigen, cytokeratins and others.

A multicenter trial evaluation of the fibrin/fibrinogen degradation products test for detection and monitoring of bladder cancer

PURPOSE

Presently there is a lack of effective, noninvasive tests for the detection and monitoring of bladder cancer. Measurement of fibrin/fibrinogen degradation products in urine has been shown to be a useful indicator of bladder carcinoma. The objective of this study was to evaluate the AuraTek FDP rapid immunoassay device for the detection of urinary fibrin/ fibrinogen degradation products associated with bladder cancer.

MATERIALS AND METHODS

A prospective multicenter study was conducted to compare AuraTek FDP with urinary cytology and hemoglobin dipstick for the detection of bladder cancer in 192 patients with a history of bladder cancer.

RESULTS

AuraTek FDP was significantly more sensitive (68%) than conventional urinary cytology (34%, p < 0.001) or hemoglobin dipstick (41%, p < 0.001) in the detection of bladder tumors, particularly for low stage low grade disease. In subjects with invasive disease (T2-T4) the AuraTek FDP test had a sensitivity of 100%. Specificity of AuraTek FDP was 96% for healthy subjects, 86% in patients with urological disease other than bladder cancer and 80% for patients under surveillance for bladder cancer but with a negative cystoscopic finding at the time of assay.

CONCLUSIONS

This simple, rapid (less than 7 minutes) point of care test is superior to conventional urine cytology and hemoglobin dipstick as an aid in the detection of bladder cancer.

Urinary fibrin/fibrinogen degradation products in transitional cell carcinoma of the bladder

Urinary fibrin/fibrinogen degradation products (FDPs) were measured in 210 specimens from 174 patients with newly or previously diagnosed transitional cell carcinoma of the bladder. They were detected in 94% of patients with deeply invasive bladder tumours (pT2-4) compared with 17% of superficial tumours. Microalbuminuria (greater than 50 micrograms/g creatinine) was also found in 80% of patients with pT2-4 lesions. Both were compared with urine cytology. Urinary FDPs are markers of bladder tumour invasion. Our results suggest that urinary FDPs are not of value in screening for the presence of bladder neoplasia but their role may be in following patients with superficial bladder tumours to detect those tumours which become invasive. The mode of excretion of the FDPs in the urine is discussed.