药品信息: Intravesical therapy for bladder cancer
With intravesical therapy, the doctor puts the drug directly into the bladder (through a catheter) rather than giving it by mouth or injecting it into a vein. This may be either immunotherapy, which causes the body’s own immune system to attack the cancer cells, or chemotherapy.
Medicines given this way mainly affect the cells lining the bladder, with little to no effect on cells elsewhere. This means that any cancer cells outside of the bladder lining, including those that have grown deeply into the bladder wall, are not treated. Drugs put into the bladder also can’t reach cancer cells in the kidneys, ureters, and urethra, or those that have spread to other organs.
For this reason, intravesical therapy is used only for non-invasive (stage 0) or minimally invasive (stage I) bladder cancers.
Intravesical immunotherapy
Bacillus Calmette-Guerin therapy: Bacillus Calmette-Guerin (BCG) is the most effective intravesical immunotherapy for treating low-stage bladder cancer. BCG is a bacterium that is related to the germ that causes tuberculosis (TB), but it does not usually cause serious disease. To treat bladder cancer, BCG is put directly into the bladder through a catheter. The body’s immune system cells are attracted to the bladder and activated by BCG, which in turn affects the bladder cancer cells. Treatment is usually started a few weeks after a transurethral resection of the tumor and is given once a week for 6 weeks. Sometimes long-term maintenance BCG therapy is given.
Treatment with BCG can cause symptoms that feel like having the flu, such as fever, chills, and fatigue. It can also cause a burning feeling in the bladder. Rarely, BCG can spread through the body, leading to a life-threatening infection. One sign of this can be a high fever (greater than 101.5°) that does not get better when you take a pain reliever (such as aspirin, ibuprofen, or acetaminophen). In such cases, you should see a doctor right away. These infections can be treated with the antibiotics used to treat TB.
Interferon: Interferons are substances naturally made by several types of cells in the body that stimulate the immune system. They can also be made in the lab and given as medicine. Interferon-alpha is the type most often used to treat cancer. It can be helpful in the intravesical treatment of bladder cancer.
Possible side effects include muscle aches, bone pain, headaches, problems with thinking and concentration, fatigue, nausea, and vomiting. These problems are usually temporary and improve after treatment is completed. Other drugs may be given along with interferon to lessen these side effects.
Intravesical chemotherapy
For this treatment, anticancer drugs are put directly into the bladder through a catheter. These chemotherapy drugs kill actively growing cancer cells. Many of these same drugs can also be given systemically (by mouth or into a vein) to treat more advanced stages of bladder cancer.
Mitomycin and thiotepa are the drugs used most often for intravesical chemotherapy. Other drugs that are used include valrubicin, doxorubicin, and gemcitabine. Delivery of mitomycin into the bladder along with heating the inside of the bladder, a treatment called electromotive mitomycin therapy, may work even better than giving intravesical mitomycin the usual way.
One advantage of giving chemotherapy into the bladder instead of as an injection into the bloodstream is that the drugs usually do not reach other parts of the body. This avoids many of the unwanted side effects that can occur with systemic chemotherapy. An exception to this is the drug thiotepa, which is rarely absorbed from the bladder and can cause side effects in the rest of the body. |