Bladder Cancer Diagnostics

Laboratory Tests and Ancillaries

Lab studies (eg complete blood count [CBC], chemistry profile that includes alkaline phosphatase) must be performed before treatment of bladder cancer to accurately determine clinical staging. Urinalysis may be done to assess hematuria, while urine culture may be used to rule out UTI, especially if with irritative symptoms.  

Urinary Cytology  

Examination of voided urine or bladder washings for exfoliated cancer cells has a high sensitivity in high-grade tumors and is a useful indicator in cases of high-grade malignancy or CIS, but it has low sensitivity in G1 tumors. It is useful as an adjunct to cystoscopy when a G3 malignancy or CIS is present. Positive voided urinary cytology may indicate a urothelial tumor anywhere in the urinary tract; however, negative cytology does not exclude the presence of a tumor.

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Imaging

Imaging Studies  

Chest imaging is indicated if invasive disease (eg lung metastasis) is suspected. CT or MRI is recommended if the tumor after cystoscopy appeared to be solid, high-grade, or suggests muscle invasion, or if radical treatment is being considered for locally advanced or metastatic disease. Pelvic MRI with or without contrast is recommended for staging of sessile or high-grade non-muscle invasive tumors in addition to CT urography. CT or MRI of the abdomen and pelvis is recommended before TURBT to characterize the lesion anatomically and to delineate depth of invasion.  

CT Scan  

The first choice for the workup of non-muscle invasive bladder cancer in many Asian countries is CT scan. CT scan with or without contrast is also the preferred imaging study for the staging of patients with muscle invasive bladder cancer. CT of the chest, abdomen, and pelvis are essential in staging localized muscle invasive bladder cancer and metastatic bladder cancer. Fluorodeoxyglucose-positron emission tomography (FDG-PET)/CT may be used in select patients with T2 muscle invasive disease and in patients with ≥cT3 disease. It may also be used to evaluate suspected or previously documented extraosseous metastasis. A 4-phase renal CT using a multidetector CT (MDCT) machine has been used for detection and staging of bladder tumors. This includes the pre-contrast phase, corticomedullary phase, nephrographic phase, and excretory phase. CT urography is used for disease staging and to detect papillary tumors in the urinary tract, which can be seen as filling defects or indicated by hydronephrosis. In patients who can safely receive intravenous agents, this is the preferred procedure. Plain CT together with retrograde ureteropyelography is an option for patients with contraindications to iodinated or gadolinium-based contrast agents. Lastly, brain CT with contrast may only be used for symptomatic patients if MRI is contraindicated.  

MRI  

Pelvic MRI with or without contrast is used for staging of sessile or high-grade non-muscle invasive tumors and muscle invasive tumors in addition to CT urography. Multiparametric MRI (mpMRI) using the Vesical Imaging Reporting and Data System (VI-RADS) scoring system may differentiate muscle and non-muscle invasive bladder cancer. MR urography is an imaging option for patients with poor renal status or iodinated contrast allergy but with a glomerular filtration rate (GFR) >30 mL/min without acute renal failure. Brain MRI may help identify symptomatic or high-risk patients with brain metastasis.  

Ultrasound  

Renal ultrasound is another imaging option for patients with contraindications for iodinated or gadolinium-based contrast agents. Transabdominal ultrasound permits characterization of renal masses, detection of hydronephrosis, and visualization of intraluminal masses in the bladder. It is also a useful tool for the detection of obstruction in patients with hematuria.  

Other Imaging Techniques  

Intravenous urography can be an alternative if CT is not available. Bone scan is performed if elevated alkaline phosphatase, hypercalcemia, or bone pain are present.  

Cystoscopy  

Cystoscopy should be done in patients presenting with symptoms of bladder cancer to determine if a lesion is present. If a lesion is present, the patient should undergo TURBT to confirm the diagnosis and to determine the extent of disease within the bladder. Urine cytology may also be obtained around the time of cystoscopy. Enhanced cystoscopy includes white light and blue light cystoscopy, and narrow band imaging. The current standard in the evaluation and staging of bladder cancer is white light cystoscopy, but in non-muscle invasive bladder cancer detection, particularly CIS, it was found that blue light cystoscopy is more effective than white light cystoscopy. Studies showed the use of narrow band imaging significantly reduces disease recurrence at 1 year in low-risk patients and results in a higher detection rate of flat lesions. Diagnosis of papillary bladder cancer ultimately depends on cystoscopic examination of the bladder and histological evaluation of the resected tissue.

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