For certain types of bladder cancer, neoadjuvant chemotherapy is used. This therapy is given before the main treatment, typically surgery. It is a systemic treatment designed to address the cancer throughout the body.
Understanding Neoadjuvant Chemotherapy for Bladder Cancer
Neoadjuvant chemotherapy involves administering anti-cancer drugs before the primary treatment, usually surgery. These powerful drugs travel through the bloodstream to destroy cancer cells or slow their growth throughout the body, differing from localized treatments.
Its main purpose is to improve the chances of a successful outcome from the subsequent main treatment. One goal is to shrink the tumor within the bladder, potentially making surgical removal easier and more complete. This tumor reduction, also known as downstaging, can lead to a more favorable pathological stage at the time of surgery.
Another aim is to eliminate microscopic cancer cells that may have already spread beyond the bladder but are too small to be detected by imaging scans. These undetectable cells, called micrometastases, can lead to cancer recurrence if not treated. By targeting these cells early, neoadjuvant chemotherapy reduces the risk of the cancer returning after surgery, contributing to better long-term survival rates.
Neoadjuvant chemotherapy is primarily considered for muscle-invasive bladder cancer (MIBC). This is a more aggressive form of bladder cancer where the tumor has grown into the muscle layer of the bladder wall. For patients with MIBC who are candidates for surgery, cisplatin-based neoadjuvant chemotherapy is commonly recommended.
Patient selection involves several considerations. Doctors assess the patient’s overall health, including kidney function, as cisplatin-based chemotherapy can affect the kidneys. The clinical stage of the cancer is also evaluated; patients with cT3–T4 disease often benefit more, while those with multifocal cT2 disease may still be considered.
The Neoadjuvant Chemotherapy Process
Neoadjuvant chemotherapy is typically administered intravenously, with drugs delivered directly into a vein, usually in the arm. This ensures the drugs circulate throughout the bloodstream to reach cancer cells wherever they are located.
The treatment is given in cycles, which are specific periods of treatment followed by rest. Each cycle can last between two to four weeks, depending on the specific chemotherapy regimen being used. For bladder cancer, patients commonly undergo about three cycles of chemotherapy before surgery. The overall timeframe for neoadjuvant chemotherapy usually spans several weeks to a few months.
Common chemotherapy regimens for bladder cancer often involve combinations of drugs. Two widely used combinations are Gemcitabine and Cisplatin (GC), and Methotrexate, Vinblastine, Doxorubicin, and Cisplatin (MVAC), or a dose-dense MVAC (dd-MVAC) regimen. These combinations are chosen for their effectiveness in treating urothelial carcinoma, the most common type of bladder cancer.
Patients may experience various side effects, as these powerful drugs can affect healthy cells. Common side effects include fatigue, nausea, vomiting, and hair loss. Additionally, chemotherapy can lower blood cell counts, leading to an increased risk of infection due to reduced white blood cells, or anemia from low red blood cells.
Healthcare teams actively manage these side effects to help patients maintain their quality of life. Anti-nausea medications are routinely prescribed to control sickness. Blood tests are regularly performed to monitor blood counts, and interventions like growth factor injections might be given to boost white blood cell production if counts drop too low. Patients should communicate any symptoms or concerns with their medical team promptly.
Monitoring Response and Subsequent Treatment
After chemotherapy, doctors assess treatment effectiveness using various methods. Imaging scans, such as CT (computed tomography) or MRI (magnetic resonance imaging) scans, are frequently used to visualize the bladder and surrounding areas. These scans help determine if the tumor has shrunk in size.
Cystoscopy, a procedure where a thin, lighted tube with a camera is inserted into the bladder, is also performed. This allows direct visualization of the bladder lining to check for any visible tumor reduction or disappearance. While cystoscopy is a standard diagnostic tool, it may not detect very flat lesions or assess cancer spread beyond the bladder.
A positive response means the tumor has significantly shrunk or, in some cases, completely disappeared from imaging and cystoscopic views. This is known as a clinical complete response. A pathologic complete response (pCR) is achieved when no detectable cancer cells are found in the tissue samples removed during subsequent surgery, which is associated with better long-term survival. Approximately 36% to 42% of patients receiving certain regimens like GC or dd-MVAC may achieve a pCR.
The typical next step after neoadjuvant chemotherapy is surgery, most commonly a radical cystectomy. This major operation involves the removal of the entire bladder, and often nearby lymph nodes. The decision to proceed with surgery is usually made about 6 to 8 weeks after chemotherapy, allowing the body time to recover.
Neoadjuvant chemotherapy aims to improve the success of radical cystectomy by shrinking the tumor and targeting microscopic cancer cells, reducing recurrence risk. Studies show it can lead to a 5% improvement in overall survival at five years compared to surgery alone.
Following surgery, ongoing follow-up and surveillance are important to monitor for any signs of recurrence. This involves regular check-ups, imaging scans, and other tests to detect and address any potential recurrence early.