Intravesical therapy is widely used in practice as an adjuvant treatment for early stage bladder cancer, following surgical transurethral resection. This is because it is a localized treatment that is administered directly into the bladder, leading to fewer systemic side effects but reduced efficacy on any metastases throughout the body.
The primary goal of intravesical therapy is to eradicate tumors from the localized area in the bladder. This may involve the use of cytotoxic or immunostimulatory agents to eliminate the abnormal cancer cells, according to the specific case and characteristics of the patient.
It is a suitable option for early stage cancers that are noninvasive (stage 0) or minimally invasive (stage 1), whereas systemic therapy is preferred for higher stage or metastatic bladder cancer. For some patients with bladder cancer, intravesical therapy is the only treatment they will need to treat the cancer. This is considered to be preferable as the therapy is associated with significantly few side effects than other treatment.
Initially, intravesical therapy involves the application of an anesthetic gel to the urethral area to numb the sensation and allow the insertion of a catheter into the urethra.
Once inserted, the catheter is gently pushed upwards until it reaches the bladder. From this point, the catheter can then used to administer a liquid drug formulation directly to the bladder, bypassing the oral or intravenous route and thus minimizing systemic effects.
The catheter can then be removed and the patient should be advised to refrain from passing urine in the next few hours, to allow the medication enough time in the bladder to have an optimal effect. After this time, the patient can relieve himself or herself as usual, or the urine may be drained with the catheter if still inserted, to eliminate the chemotherapy drug from the body. Care should be taken that urine passed in the next 6 hours does not come in contact with the skin, as it may cause an adverse reaction.
Immunotherapy agents stimulate the immune system to attack the cancer cells and include Bacillus Calmette-Guerin (BCG) and interferon.
BCG is the most effective and is a bacterium that attracts the cells of the immune system to the area, which also affect the cancer cells in the bladder. This treatment is usually given in six separate doses, once a week for six weeks. Side effects of treatment with BCG may include flu-like symptoms, including fever, chills and fatigue. In rare cases, it can spread throughout the body and cause an infection similar to tuberculosis.
Interferon-alpha is a substance that naturally has a stimulatory effect on the immune system. Side effects of treatment with this may include muscle aches, bone pain, headaches, nausea, vomiting, fatigue and loss of concentration.
Cytotoxic agents used in intravesical chemotherapy target the cell division process of all cells in the area. There are a wide range of cytotoxic agents that may be indicated, including mitomycin C, valrubicin, doxorubicin, epirubicin, and gemcitabine. The primary side effects associated with this therapy are irritation and burning, which are localized to the bladder.