The TNM staging system is generally used for bladder cancer, although an alternative—the Jewett-Strong- Marshall system—is also used. There are slight differences in the two methods.
A major problem in clinical staging is the inaccuracy rate of 30 to 50 percent in determining precisely the extent of muscle and lymph node involvement when compared with the surgical or pathological staging of a tissue specimen.
In 20 to 40 percent of cases, high-grade (Grade 3) and high-stage (T3 and T4) lesions have lymph node metastases found at the time of surgery.
