Biological treatment for bladder cancer

What are the biological treatment methods for bladder cancer? There are many types of bladder tumors, including epithelial tumors and mesenchymal tumors, and epithelial tumors include urothelial tumors, squamous epithelial tumors, and glandular epithelial tumors. Different tumors have different biological characteristics and different effects and harms on the body, so the treatment methods are also different. The vast majority of bladder tumors are urothelial tumors, so this section will focus on the treatment of urothelial tumors.

Treatment options for bladder cancer

There are many treatments for bladder tumors. For each patient, the treatment method to be used must be specifically considered based on the patient's tumor tissue type, case classification, general condition, patient's wishes, hospital conditions, physician's skills, and relevant social, cultural, and economic backgrounds.

Due to limited space, only the most common treatment methods are introduced.

Transurethral resection of bladder tumors (TURBt): This is the internationally recognized standard surgical method for the treatment of superficial bladder tumors. Superficial tumors refer to tumors with a clinical stage of Ta or T1. These tumors are limited to the mucosa and submucosa and do not invade the muscular layer. Therefore, the probability of lymphatic and hematogenous metastasis is extremely low, and the 5-year survival rate is greater than 80%. Among them, only 10% to 15% of patients ultimately need other more aggressive treatments.

Transurethral resection of the bladder is also suitable for invasive bladder cancer. Even a 5 cm tumor can be removed by transurethral resection. At the same time, the initial transurethral resection of bladder tumors is also the most reliable method to determine the depth of bladder tumor infiltration. However, despite this, the accuracy of staging is still only relative. For a specific pathology, different pathologists will get different staging conclusions.

The probability of myometrial invasion after transthoracic resection of well-differentiated tumors confined to the epithelium is not high, but for poorly differentiated tumors that infiltrate the lamina propria, the probability of myometrial invasion can be as high as 40%. Therefore, T1 tumors, especially poorly differentiated Tis tumors, should be aware of the potential for progression.

It is common for T1 tumors to be incompletely removed during surgery, even though the physician who performed the electroresection believed that the tumor was completely removed. A German study reported that more than 40% of T2 tumors were found to have residual tumor tissue after the first electroresection 6 weeks after the first electroresection. The efficacy of preventive intravesical instillation after electroresection of bladder cancer also supports the existence of residual tumor after electroresection from another perspective.

Partial cystectomy: Partial cystectomy has a history of more than 100 years and was widely used before the development of TURBt surgery. This surgery is relatively simple, can preserve bladder function, and is easily accepted by patients.

Indications: Mainly superficial bladder cancer with large tumor, wide tumor pedicle or difficult to remove TURBt, local invasive bladder cancer without distant metastasis, bladder diverticulum cancer and patients who refuse radical cystectomy even though the tumor is T2 or T3a invasive bladder cancer

Relative contraindications: carcinoma in situ, recurrent or multiple tumors, tumors extending beyond the bladder wall, invasion of the bladder neck or prostate, bladder capacity that is too small after tumor resection (less than 1/3 of the normal capacity), and extremely poor physical condition of the patient.

Generally, the 5-year survival rate of patients with T2 and T3a stages after partial cystectomy is 70%, and the incidence of postoperative tumor implantation and metastasis is 1% to 3%.

4. Radical cystectomy: The indications for radical cystectomy mainly include

1. Invasive bladder cancer (T2 and T3), especially when the tumor diameter is >3 cm, multiple, with ureteral obstruction, prostate invasion, and bladder base tumor.

2. Multiple papillary tumors (Ta and T1), recurrent superficial bladder cancer accompanied by severe mucosal lesions, combined with extensive carcinoma in situ, rapid recurrence and a tendency to increase in malignancy.

Pelvic lymph node clearance after cystectomy can clarify the stage of bladder cancer and estimate the prognosis, because when there is pelvic lymph node metastasis, there is often distant metastasis.

Radical cystectomy must be performed in conjunction with urethral diversion surgery. The operation has a high risk and is prone to postoperative infection complications. The patient's physical condition must be fully assessed before the operation. The general method after the operation is to hang a urine bag, and the patient needs a certain amount of time to adapt.