Diagnosis of bladder cancer should be aimed at clarifying the morphological structure of the tumor, determining the degree of malignancy, the depth of invasion of the bladder wall, the presence of regional and distant metastases. A cytological examination of urine sediment is informative in about half of patients, and the sensitivity of the method increases with multicentric lesions of a high degree of malignancy, with carcinoma in situ.
Recently, methods of immune diagnostics based on monoclonal antibodies have become widespread: BTA (bladder tumor antigen) stat Test (determination of bladder tumor antigen), BTA TRAC Test, NMP-22 Test (determination of nuclear matrix proteins responsible for DNA replication). The sensitivity of the methods is 50-80%, specificity 60-70%. Of interest is the use of these tests for screening for bladder cancer.
Cystoscopy , with mandatory ureteroscopy, is the main diagnostic method for bladder cancer. To increase the informational content of the method, fluorescence cystoscopy is performed, in which a solution of 5-aminolevulinic acid is injected into the bladder, followed by examination of the mucous membrane in blue-violet light. Tumor tissues have an increased ability to accumulate protoporphyrin IX. The informational content of the technique is more than 90% (20% higher than with conventional cystoscopy), which leads to a 2-fold decrease in the frequency of relapses in the 1st year of observation.
Ultrasound tomography (transabdominal, transrectal, transurethral) is an important method for the diagnosis of bladder cancer. The method allows you to evaluate the local distribution of the process, the depth of invasion into the wall of the bladder, the state of regional lymph nodes, and transurethral ultrasound is more informative in the diagnosis of surface tumors. Excretory urography is more precise and allows to identify tumors of the upper urinary tract, to evaluate the functional state of the kidneys. Additional information can be obtained by ascending cystography, which is often carried out with the introduction of 100-150 ml of oxygen in addition to the radiopaque substance in the bladder (Kneise-Schober method). X-ray and magnetic resonance imaging are more informative in the diagnosis of invasive forms of bladder cancer. The final diagnosis is made after a biopsy, the tasks of which are morphological confirmation of the diagnosis, determining the depth of invasion of the bladder wall, and identifying the multiple nature of the lesion. The biopsy can be “cold” when the material for examination is taken with forceps through a cystoscope, and it is extremely difficult to determine the depth of invasion. Another method is transurethral resection (TUR), in which a complete removal of the tumor is possible, as well as determining the depth of invasion. Further diagnostic measures are aimed at identifying regional and distant metastases. The most commonly affected are the pelvic lymph nodes, liver, lungs, and bones. Half of patients with invasive bladder cancer have distant metastases.