Urothelial Bladder Cancer: Screening with Urine-Based Tumor Markers

Abstract

Urothelial bladder cancer is the fourth most prevalent cancer in males and the ninth most prevalent cancer in females (NCI Cancer Screen 2007). An estimated 67,160 new cases of bladder cancer and 13,750 deaths from bladder cancer are expected in 2007 in the United States (Jemal et al. 2007). In addition, bladder cancer is considered the most costly ­cancer from diagnosis to death (Botteman et al. 2003). In the United States, bladder ­cancer is predominately transitional cell carcinoma subtype and it affects a defined population with established risk factors: age, tobacco, and chemical exposures.

The natural history of bladder cancer provides a distinct opportunity for benefits to be gained from early detection with screening. Low-grade, noninvasive (Ta), lesions exhibit high recurrence rates but progression to invasive disease is uncommon (Malkowicz 2002). As a result prognosis for these patients is excellent with long-term survival greater than 95% (Malkowicz 2002). Invasion of the lamina propria (T1) portends a worse prognosis than Ta disease defined by an increased rate of recurrence (80%) and progression (40–50%) (Malkowicz 2002). However, bladder preservation is possible in up to 55–75% of patients with T1 high-grade lesions (Foresman and Messing 1997). Moreover, with aggressive surveillance, prognosis of patients with high grade T1 disease is significantly better compared to patients presenting with muscle-invasive disease (Foresman and Messing 1997). Unfortunately, with current detection methods, muscle invasion is present in 15–25% of patients diagnosed with bladder cancer (Messing 2002). In addition, many patients will have occult metastasis at presentation. Because of the large discrepancy in morbidity/mortality which is clearly dependent on stage, detection of bladder cancer at an earlier stage, prior to muscle invasion or metastasis, could render a significant improvement in patient morbidity and disease-specific survival.