Bladder cancer is a malignant tumor that occurs on the mucosa of the bladder. It is the most common malignant tumor in the urinary system and one of the ten most common tumors in the whole body. It accounts for the first place in the incidence of genitourinary tumors in China. The etiology of bladder cancer is complex, with both intrinsic genetic factors and extrinsic environmental factors. The two major risk factors are smoking and occupational exposure to aromatic amine chemicals. Smoking is the most certain risk factor for bladder cancer, which can increase the risk rate of bladder cancer by two to six times.
Another important risk factor is long-term exposure to carcinogens such as aniline, diaminobiphenyl, 2-naphthylamine and 1-naphthylamine. The initial clinical manifestation of over 90% of patients with bladder cancer is hematuria, which usually presents as painless, intermittent, visual hematuria throughout, or sometimes microscopic hematuria. The hematuria may occur only once or last for one to several days and may reduce or stop on its own. Sometimes the coincidence of the patient taking medication and the hematuria stopping on its own often gives the illusion that the patient is “cured”. Some patients may experience a recurrence of hematuria after an interval of time.
In cases of painless hematuria over the age of 40, the possibility of urological tumors, especially bladder cancer, should be considered. Further relevant tests should be performed. The examination methods include routine urine examination, urine exfoliative cytology, urinary ultrasound and other tests. Based on the results of the above examinations, it is decided whether to perform cystoscopy, intravenous urography, pelvic CT, pelvic MRI and other examinations to clarify the diagnosis. Among them, cystoscopy is the most important method to diagnose bladder cancer. Uroepithelial carcinoma of the bladder is divided into non-muscle invasive uroepithelial carcinoma and muscle invasive uroepithelial carcinoma.
Patients with non-muscle invasive uroepithelial carcinoma are mostly treated with transurethral bladder tumor electrosurgery and postoperative treatment with bladder irrigation to prevent recurrence. Patients with muscle-infiltrating uroepithelial carcinoma and squamous and adenocarcinoma of the bladder are mostly treated by total cystectomy, and some patients can be treated by partial cystectomy. Patients with muscle-infiltrating uroepithelial carcinoma can also be treated with neoadjuvant chemotherapy + surgery first. Metastatic bladder cancer is primarily treated with chemotherapy. Reducing environmental and occupational exposures may reduce the risk of developing uroepithelial carcinoma.
Approximately 70% of patients recur after transurethral electrodesiccation, and postoperative treatment with intravesical instillation of BCG or chemotherapeutic agents may reduce the recurrence rate to 25% to 40%. The 5-year survival rate after total cystectomy for patients with invasive bladder cancer is 60% to 70%.