The standard of care for muscle-invasive bladder cancer is radical cystectomy, with outcomes closely related to T-stage and N-stage and an overall 5-year survival rate of 54.5% to 68% for patients after surgery. However, the cost is the loss of the bladder. The available data suggest that the bladder can be preserved in this group of patients using a combination of radiotherapy and/or chemotherapy, and the 5-year survival rate after treatment can be 40% to 60%, with the benefit of preserving the bladder, improving the quality of life, and providing the opportunity for salvage surgery even if the tumor recurs.
There are two main types of integrated bladder preservation treatment: 1. Combined radiotherapy and/or chemotherapy based on radical transurethral resection of bladder tumor (TURBt); 2. Combined radiotherapy and/or chemotherapy based on partial cystectomy.
Bladder cancer is sensitive to chemotherapy regimens containing cisplatin, with an overall efficiency of 40% to 75%, of which 12% to 20% of patients achieve complete remission of local lesions and about 10% to 20% of patients can achieve long-term survival. However, studies have shown that chemotherapeutic drugs have been sufficiently diluted and mixed by blood to reach the tumor area, while most of the chemotherapeutic drugs have also been shunted to reach non-tumor organs. Since the free base bonds of chemotherapeutic drugs are easily bound to plasma proteins, the amount of biologically active drugs containing free base bonds by the time they reach the target organs is reduced, making them less effective. At the same time, chemotherapy side effects often make patients “fearful”, and in the traditional concept, chemotherapy is almost equal to white blood cell decline, nausea, vomiting and hair loss.
Therefore, it is important to find a less toxic route of administration without compromising the efficacy of chemotherapy. Arterial chemotherapy refers to the direct infusion of chemotherapeutic drugs into the tumor or the organ where the tumor occurs through the tumor’s nutrient artery with a slender catheter, so that the local drug concentration is greatly improved, avoiding the drawback that the intravenous infusion has to flow through the whole body before a very small amount of drugs enter the tumor. In 1989, Kubota et al. first reported arterial chemotherapy, which has the advantage of increasing local drug concentrations in the bladder while reducing systemic chemotherapy toxicity. The EAU guidelines state that arterial catheter chemotherapy is more effective than systemic chemotherapy for localized tumors. Experimental research shows that the drug concentration in local tissues during arterial chemotherapy is 100-400 times higher than that in the whole body, while the drug concentration in tumor tissues is 5-20 times higher than that in normal tissues. The efficiency of chemotherapeutic drugs in killing tumors is closely related to the initial dose of drugs. The higher the initial dose, the stronger the efficacy of killing tumor cells, and thus the local control rate is high.
Bladder artery embolization chemotherapy: Using the Seldinger technique, the right femoral artery is cannulated and the end of the multi-lateral hole catheter is first placed at the bifurcation of the abdominal aorta for imaging to understand the opening of both internal iliac arteries, and a 5F Cobra catheter is inserted into the left internal iliac artery for imaging to understand the opening of the bladder artery and the presence of intrapelvic metastases, and injecting chemotherapy drugs. The catheter is then introduced into the bladder artery under the guidance of an ultra-smooth guidewire for proximal embolization, and post-embolization angiography is performed to understand the embolization. In other words, an organic combination of ultrafine drug and embolic agent is injected into the target artery together to “starve” the bladder cancer with a two-pronged approach. The catheter end then enters the right internal iliac artery for imaging, chemotherapy, and super-selective access to the right bladder artery for embolization. After slow infusion of diluted chemotherapy drugs for more than 20 minutes on each side, the puncture site was dressed with pressure and placed on bed rest for 24 hours. Intravenous hydration, diuretic and hepatoprotective drugs were given. The patient’s liver and kidney function and blood count were also monitored.
Minimally invasive intervention has opened the era of local chemotherapy, which highly concentrates anti-cancer drugs and injects them directly into bladder cancer lesions, which not only improves the efficacy but also avoids the harm to normal tissues caused by traditional chemotherapy and greatly reduces the side effects, allowing bladder cancer patients to improve their quality of survival and live longer.