Bladder Cancer. Treatment
A. Intravesical Chemotherapy: Immuno- or chemotherapeutic agents can be delivered directly into the bladder by a urethral catheter. They can be used to eradicate existing disease or to reduce the likelihood of recurrence in those who have undergone complete transurethral resection. Such therapy is more effective in the latter situation. Most agents are administered weekly for 6–12 weeks. The use of maintenance therapy after the initial induction regimen may be beneficial. Efficacy may be increased by prolonging contact time to 2 hours. Common agents include thiotepa, mitomycin, doxorubicin, and BCG, the latter being the most effective agent when compared with the others. Side effects of intravesical chemotherapy include irritative voiding symptoms and hemorrhagic cystitis. Systemic effects are rare. Patients who develop symptoms from BCG may require antituberculous therapy.
B. Surgical Treatment: Although transurethral resection is the initial form of treatment for all bladder cancers as it is diagnostic, allows for proper staging, and will control superficial cancers, muscle infiltrating cancers will require more aggressive treatment. Partial cystectomy may be indicated in patients with solitary lesions and those with cancers in a bladder diverticulum. Radical cystectomy entails removal of the bladder, prostate, seminal vesicles, and surrounding fat and peritoneal attachments in men and in women also the uterus, cervix, urethra, anterior vaginal vault, and usually the ovaries. Bilateral pelvic lymph node dissection is performed simultaneously.
Urinary diversion can be performed using a conduit of small or large bowel. However, continent forms of diversion have been developed that avoid the necessity of an external appliance.
C. Radiotherapy: External beam radiotherapy delivered in fractions over a 6- to 8-week period is generally well tolerated, but approximately 10–15% of patients will develop bladder, bowel, or rectal complications. Unfortunately, local recurrence is common after radiotherapy (30–70%). Increasingly, radiotherapy is being combined with systemic chemotherapy in an effort to improve local and distant relapse rates.
D. Chemotherapy: Fifteen percent of patients with newly diagnosed bladder cancer will present with metastatic disease, and 40% of those thought to have localized disease at the time of cystectomy or definitive radiotherapy will develop metastases usually within 2 years after the start of treatment. Cisplatin-based combination chemotherapy will result in partial or complete responses in 15–35% and 15–45% of patients, respectively.
Combination chemotherapy has been integrated into trials of surgery and radiotherapy. It has been used before each in an attempt to preserve the bladder and decrease recurrence rates. Alternatively, it has been employed postoperatively in patients who have undergone cystectomy and have been found to be at high risk of recurrence. In current practice, adjuvant chemotherapy when indicated—ie, when the primary tumor invades perivesical fat or adjacent organs or when lymph nodes are found to have metastatic disease—is being offered mainly to patients being treated with radical cystectomy. It is used less often for patients with unresectable disease (extension to pelvic side wall).