Which tumor marker is associated with cancer of the urinary bladder?

The correct answer is associated with the detection of cancer of the urinary bladder due to its specific relationship to transitional cell carcinoma, the most common type of bladder cancer. Nuclear matrix protein serves as a marker for bladder cancer as it is released into the urine and can indicate the presence of malignancy. Its concentration correlates with tumor presence and activity, making it a valuable tool for diagnosis and monitoring.

In contrast, the other options are associated with different cancers or are not used specifically for urinary bladder cancer. For example, CA-19-9 is primarily linked to pancreatic and gastrointestinal cancers, while CA-72-4 has associations with gastric cancer. Cathepsin-D is more often linked to breast cancer and some other solid tumors, but not specifically to bladder cancer. Thus, nuclear matrix protein is the most relevant marker for assessing urinary bladder malignancies.