Introduction

Bladder cancer affects a vital organ responsible for storing and releasing urine. One of the primary treatments for bladder cancer is chemotherapy. This essay seeks to look in-depth at how chemotherapy for bladder cancer works. We will cover its principles, types, side effects, and the recent advancements in chemotherapy for bladder cancer.

Bladder cancer typically starts in the lining of the bladder and can be categorised into two main types: 

• Non-muscle invasive bladder cancer (NMIBC) 
• Muscle-invasive bladder cancer (MIBC)

Treatment options vary depending on the stage and type of bladder cancer, with chemotherapy playing a crucial role, particularly in cases of MIBC.

Principles of chemotherapy for bladder cancer

Chemotherapy is a systemic treatment that uses drugs to kill or inhibit the growth of cancer cells throughout the body. Unlike localised treatments such as surgery or radiation therapy, chemotherapy circulates through the bloodstream, reaching cancer cells beyond the bladder.

Neoadjuvant Chemotherapy: Neoadjuvant chemotherapy is administered before surgery and aims to shrink tumours, making them more amenable to surgical removal. This approach is often used for MIBC to improve surgical outcomes.

• Adjuvant Chemotherapy: Adjuvant chemotherapy is given after surgery to eliminate any remaining cancer cells and reduce the risk of recurrence. This strategy is common in cases where the cancer has invaded the muscle layer of the bladder

Chemotherapy drugs

Chemotherapy can be administered through a cannula, a central line, a PICC line or an implantable port. Chemotherapy for bladder cancer can also be put into the bladder through the urethra into the inside of the bladder. 

Several chemotherapy drugs are used in the treatment of bladder cancer. Commonly employed drugs include:

• Cisplatin: Cisplatin is a platinum-based drug that damages the DNA of cancer cells, preventing them from dividing and growing. People who have cisplatin also need to be given mannitol and excess fluids to prevent the cisplatin from damaging the kidneys, this is called nephrotoxicity³
• Gemcitabine: Gemcitabine disrupts the process of DNA replication, inhibiting the growth of cancer cells
• Methotrexate: Methotrexate is an immunosuppressant that interferes with the synthesis of DNA and RNA, impeding the growth of rapidly dividing cells
• Vinblastine: Vinblastine disrupts the microtubule structure of cancer cells, inhibiting their ability to divide
• Mitomycin:Mitomycin works by generating oxygen radicals and alkylates the DNA. Mitomycin introduces DNA cross-links between the two strands of DNA, which prevents DNA synthesis and inhibits RNA and protein synthesis in hypoxic cells¹
• Carboplatin: Carboplatin is another platinum-based drug with a mechanism of action similar to cisplatin, making it an alternative option in bladder cancer treatment regimens
• Doxorubicin: Doxorubicin interferes with DNA and RNA synthesis, inhibiting cancer cell growth and proliferation
• Fluorouracil: Fluorouracil, also known as 5-FU, disrupts DNA synthesis and interferes with cell division, thereby impeding the growth and spread of cancer cells

Side effects of chemotherapy

While chemotherapy effectively targets cancer cells, it also affects normal, healthy cells, leading to side effects. Common side effects of chemotherapy for bladder cancer may include:

• Nausea and vomiting
• Fatigue
• Hair loss
• Anaemia
• Increased susceptibility to infections
• Peripheral neuropathy (nerve damage)
• Changes in kidney function

Patients must communicate openly with their healthcare team to manage and mitigate these side effects effectively.

Recent advancements and emerging therapies

Researchers are continually exploring new approaches to enhance the effectiveness of chemotherapy and minimise side effects. Examples of treatments that have fewer side effects include immunotherapy, targeted therapies, and personalised medicine. These types of treatments are emerging as promising avenues in the treatment of bladder cancer due to the ability of the patients to tolerate the treatment better. These advancements aim to tailor treatment plans to the unique genetic makeup of individual tumours, improving overall outcomes.

Summary

Chemotherapy remains a critical component in the comprehensive treatment of bladder cancer, particularly in cases of muscle-invasive disease. While it comes with side effects, ongoing research and advancements offer a great deal of hope for more targeted and less toxic therapies in the future. This will eventually result in less severe side effects for patients with bladder cancer. A collaborative approach between patients and healthcare workers is essential to navigate the challenges of bladder cancer treatment and optimise the trade-off between symptom severity and efficacy of treatment when it comes to different chemotherapy drugs.²