Bladder cancer originates in the cells lining the bladder, a hollow organ in the lower abdomen that stores urine. This article clarifies how bladder cancer can spread, specifically addressing its impact on the kidneys.
How Cancer Spreads
Cancer cells possess the ability to detach from their original tumor site. These cells can then spread throughout the body through a process known as metastasis. One way cancer can spread is by direct extension, where the tumor grows into nearby tissues or organs.
Cancer cells can also enter the lymphatic system, a network of vessels and nodes that are part of the body’s immune system. Once in the lymphatic system, these cells can travel to regional lymph nodes and potentially to more distant parts of the body.
The bloodstream provides another route for cancer cells to travel, a process called hematogenous spread. Through the blood vessels, cancer cells can reach distant organs and establish new tumors.
Bladder Cancer and Kidney Impact
Bladder cancer can spread to other parts of the body, including the kidneys, though less commonly. Direct metastasis of bladder cancer cells to kidney tissue is not a frequent occurrence compared to spread to other sites like lymph nodes, bones, or lungs. When it occurs, it typically happens in advanced stages, often through the bloodstream (hematogenous spread). In rare and advanced scenarios, a large bladder tumor might directly invade an adjacent kidney.
It is important to distinguish direct metastasis to the kidney tissue from another way bladder cancer can affect kidney function. Bladder tumors, especially those located near the ureters, can block the flow of urine from the kidneys to the bladder. This obstruction can lead to a condition called hydronephrosis, where urine backs up and causes the kidney to swell. While hydronephrosis impacts kidney function, it does not mean the cancer has spread into the kidney tissue itself; rather, it is a mechanical complication.
Detecting and Treating Advanced Bladder Cancer
When bladder cancer is suspected of having spread, healthcare professionals use various diagnostic methods to determine the extent of its reach. Imaging techniques are commonly employed, such as computed tomography (CT) scans of the abdomen and pelvis. Magnetic resonance imaging (MRI) or bone scans may also be used to identify potential spread to other areas, including bones.
Treatment approaches for advanced bladder cancer, particularly when it has spread, often involve systemic therapies that treat the entire body. These can include chemotherapy, which uses drugs to kill cancer cells, or immunotherapy, which helps the body’s immune system fight the cancer. Targeted therapy, designed to attack specific vulnerabilities in cancer cells, can also be an option. Radiation therapy might be used to manage symptoms or treat specific areas of spread.