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.