Medihub - Medical Information - Urology

In Singapore, bladder cancer is the 7th most common cancer in both males and females. Men are affected 3 times more commonly than women. The causes for bladder cancer are ageing, chemical agents and cigarette smoking.
The most common presentation is painless gross haematuria (blood in the urine) [Fig 1]. Sometimes it may present with irritative bladder symptoms like frequency of urination. Quite commonly, the diagnosis of bladder cancer is delayed because haematuria is intermittent or attributed to other causes eg. infection.

Fig 1: Blood in the urine is the most common sign

Diagnosis
Since haematuria can arise from any part of the urinary tract, the best initial investigation is a radiological test called an Intravenous Urogram (IVU). It involves the injection of contrast material into the vein which is then excreted by the kidney to outline the urinary tract.

Fig 2. IVU to show a huge bladder tumour over the right side of the bladder

A bladder tumour may show as a filling defect if the tumour is large enough [Fig 2]. Sometimes, an ultrasound examination may also show a tumour in the bladder if it is more than 1 cm. A negative IVU or ultrasound does not rule out bladder cancer as small lesions < 1 cm may not be obvious. As such, a cystoscopy is mandatory for haematuria even if the IVU or ultrasound is reported as normal.

Cystoscopy can be carried out under local anaesthesia in the clinic with a flexible instrument without much discomfort [Fig 3].

Fig 3. Flexible cystoscopy can be done under local anaesthesia in the clinic

Treatment
Once the diagnosis of a bladder lesion is confirmed, endoscopic surgery is needed, not only to surgically remove the tumour but also to stage it. General anesthesia is usually given and it may take up to 1 hour to resect the tumour.

A resectoscope is used to remove the tumour which are then assessed by the pathologist as to its grade and the depth of invasion [Fig 4]. Biopsies of normal looking bladder are also done so as not to miss early tumours of the bladder lining (carcinoma-in-situ).

Fig 4. The staging of bladder cancer

At the time of diagnosis, 80% of bladder tumours are superficial, i.e. confined to the bladder lining. The other 20% are invasive disease (invading the muscle layer of the bladder). Invasive tumours will eventually spread to the lymph nodes or distant organs, especially the lungs, bones and liver.

Superficial tumours carry a good prognosis but do tend to recur frequently and may have a risk to becoming invasive in the future especially if the pathological grade is of the aggressive type or if carcinoma-in-situ is present. Prognosis for invasive disease is poor, hence it is important to treat bladder cancer at its early stage, i.e. before it has gone into the muscle layer.

After endoscopic tumour resection of superficial bladder tumours, periodic surveillance cystoscopies are needed to pick up recurrences, initially 3-monthly for the first year, then 6-monthly subsequently to yearly depending on the behaviour of the tumours.

Those at high risk of recurrence, eg. multiple tumours, high-grade and those with carcinoma in situ can be treated additionally with a choice of several anticancer agents instilled into the bladder (intravesical therapy) to prevent recurrence. A typical treatment protocol would consist of weekly instillation for 6 weeks. Common agents used are Mitomycin C, and BCG.

Treatment of patients with invasive bladder cancer has to be individualised according to the general status of health, extent of cancer and personal preferences. Complete surgical removal of the bladder (radical cystectomy) for muscle invasive cancer of the bladder provides the best chance of cure.

Partial cystectomy is seldom done as most bladder tumours are of the transitional cell type and disease may recur in the remaining bladder. When a radical cystectomy type of operation is done, a procedure to divert the urine from the kidneys and ureters into a short segment of small bowel fashioned as an ileal conduit which appears as a stoma on the abdominal wall [Fig 5]. Urine is drained into an external collection bag (urostomy). This type of diversion remains the most popular as it is relatively easier and quicker to construct and with low complication rates.

For younger patients and those who wish to remain continent or avoid a urostomy, it is possible to construct a 'new bladder' using bowel which is reconnected to the native urethra in order that the patient can void normally. Although there is no need to wear an external bag, self intermittent catheterisation 4 times a day may be needed as such a neobladder may not empty well or get blocked with mucus.

As such types of operations are more difficult and longer to perform, only motivated and fit, young patients are suitable candidates.

Although radiotherapy allows bladder conservation, the 5 year survival for patients with deeper muscle invasion is only 20%-40%.

Fig 5. Ileal conduit drains the urine via a segment of small intestine after a radical cystectomy