According to Canadian Cancer Statistics, bladder cancer is the fifth most common
cancer, accounting for more than 4% of all cancers or 7,800 cases per
year.1 Of all
incidents of bladder cancer cases at first diagnosis, about 80% were
non-muscle invasive bladder cancer (NMIBC) and 20% were muscle invasive and
advanced bladder cancer.2
Smoking is the main risk factor of bladder cancer.2,3 Other risk factors include exposure to chemicals such as
aromatic compounds, radiation and chemotherapy.2,3 The most common symptom of bladder cancer is the presence of
blood in the urine.2
Bladder cancer is diagnosed by means of cystoscopy and transurethral resection of
the bladder tumor (TURBT) in combination with urine analysis and cytology.2,4 The tumors are classified based on the degree
of invasion into layers of tissues; CIS (flat on surface or carcinoma in situ), Ta
(raspberry growth on surface), and T1 (moves into submucosa layer) are those not yet
invading into the muscle or NMIBC, while T2a, T2b, T3b and T4a are those invade
deeper into the muscle layer and perivesical fat tissue.2 About 60% of NMIBC
are Ta type, while CIS and T1 account for 10% and 30%,
respectively.3
After the initial removal of NMIBC by TURBT, tumors can come back (recurrence) or
come back and invade into the muscle layer (progression).2 Tumors are graded based on
the risk of progression and metastasis.3 For instance, Ta tumors are usually low grade
(non-aggressive) but have high risk of recurrence and just require repeated
scraping, while CIS and T1 tumors are high grade (aggressive), have a high risk of
progression to muscle layer and require more aggressive treatment.2
Visibility of tumors is very important during TURBT, in particular flat lesions such
as CIS or low-graded tumors are often missed under standard white light
cystoscopy.5 A
new technique termed “blue light” cystoscopy have been introduced to
improve the visibility of tumors by using a photosensitizing agent and fluorescent
light in the photodynamic diagnosis of NMIBC.4 In fluorescent cystoscopy, the
photosensitizing agent such as 5-aminolevulenic acid (5-ALA) or hexaminolevulinate
(HAL), a derivative of 5-ALA, are first instilled into the bladder.4 The drug then incorporates
into the urothelial cytoplasm where abnormal cells appear red and normal cells
appear blue green upon illumination with fluorescent light.4 Thus, “blue
light” or fluorescent cystoscopy may help the detection of tumors more
accurately and may reduce the risk of recurrence and progression compared to white
light cystoscopy. HAL needs a much shorter instillation time than 5-ALA and has been
approved only for detection of bladder cancer in Europe and USA since
2010.4 HAL,
branded as Cysview, has been approved by Health Canada since November 2015 as an
adjunct to cystoscopy for the detection of NMIBC in patients with known or suspicion
of bladder cancer.6,7
The aim of this report is to review the clinical utility of “blue
light” cystoscopy in patients with suspected NMIBC undergoing TURBT.
About the Series
Rapid Response Report: Summary with Critical Appraisal
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