The urinary bladder is a muscular organ that is lined on the inside with plenty of mucous membrane. In the majority of cases, a bladder tumor originates from this mucous membrane and grows unnoticed for a very long time.
With increasing age, many women and men suffer from problems urinating and it is often purely incidental findings that lead to the diagnosis of bladder cancer. Nevertheless, around 75% of tumors are still localized to the mucous membrane when first diagnosed and are therefore easily treatable.
In 25% of cases, however, the bladder cancer has already reached the muscle layer of the bladder and in some cases has already spread to the prostate (in men) or the uterus(in women), both of which are neighboring abdominal organs.

The exact causes of bladder cancer are not yet known. However, there are a few known risk factors that can trigger bladder cancer. These include, first and foremost, smoking or passive smoking. Doctors believe that around 30 to 70 % of all bladder tumors are caused by smoking. This is followed in second to fourth place:
- Occupational risks, especially when handling organic solvents,
- Inflammations such as chronic urinary bladder infections, schistosomiasis (the so-called couple fluke from the tropics and, more recently, sexually transmitted diseases such as gonococci (the causative agent of gonorrhea) and
- drugs, e.g. cyclophosphamide (an ingredient in many cancer drugs).
Bladder cancer as an occupational disease: frequent contact with risk substances
According to analyses, the highest occupational risk of bladder cancer is found among
- Metal workers,
- members of the armed forces,
- cleaning staff,
- painters,
- hairdressers and
- workers in the rubber industry.
They are increasingly exposed to aromatic amines and polycyclic aromatic hydrocarbons, which are found in petroleum and fuels, soot, tar, tobacco smoke, dyes, rubber products, solvents and plasticizers, for example.
Also
- Brewery workers,
- electricians,
- firefighters,
- healthcare workers and
- blast furnace workers and
- waiters
can be affected.
Bladder cancer is initially not noticeable or only very unspecific. Under certain circumstances, haematuria (blood in the urine) may occur, which can be the first sign of bladder cancer and always requires medical clarification.
However, blood in the urine also occurs in other diseases, such as kidney stones, cystitis or severe urinary tract infections. However, only a urologist can clarify what it is actually about.
These symptoms can indicate bladder cancer:
- Painless hematuria (blood in the urine)
- Increased urge to urinate
- Problems urinating
- Pressure on the bladder
Pain occurs late in bladder cancer and is usually a sign that the tumor has already penetrated deep into the muscle layer.
The suspicion of a bladder tumor is naturally a shock for most people, but it is nevertheless necessary to clarify this suspicion diagnostically. There is no reliable urine or blood test, which is why cystoscopy is the most informative test.
The doctor will first take a medical history in order to clarify any possible risks, such as smoking or occupational hazards for bladder cancer. As a rule, the urologist will then routinely perform a palpation of the kidney and bladder region.
Urine test strips help to detect hidden blood in the urine, which is an important indication of bladder cancer.
However, the most important examination for suspected tumors is cystoscopy. Under local anesthesia and using a lubricant, a thin, soft tube (cystoscope) is inserted through the urethra into the bladder. This is associated with a brief feeling of pressure at the junction of the bladder sphincter, as the doctor naturally has to overcome the inward force of the bladder sphincter.
The cystoscopy itself is painless. The urologist will use a camera in the tube to take a picture of the inside of the bladder and locate the possible tumor focus. It is also possible to remove a piece of tumor tissue using small tissue forceps. This so-called biopsy is then later examined pathologically to determine the type of bladder cancer and its stage. This is essential in order to be able to plan the best possible treatment.

Image of the bladder mucosa from a cytoscopy © Courtesy of Dr. med. Robert Hefty, Urology, Heidenheim Clinics.
If the bladder cancer is already well advanced and has grown into the muscle layer, surgery is usually performed as quickly as possible and the bladder is completely removed (= radical cystectomy).
During follow-up care, it is then necessary to examine for possible metastases using X-rays or computer tomography. In the case of bladder cancer, these tend to settle in the lymph nodes, liver, lungs and bones and generally lead to a poor prognosis.
As already mentioned, treatment depends very much on the type of tumor and its stage, but also on where exactly the tumor is located. From the doctor's point of view, a distinction is made between superficially growing and infiltrating bladder tumors.
If the cancer is localized, small and has not yet penetrated far into the bladder wall, the tumour is usually removed by cystoscopy. The procedure is painless and is performed under local anesthesia. Depending on whether the edges of the incision are pathologically clean or also contain mainly tumor cells, a second surgical procedure may be necessary.
This is followed almost immediately by local chemotherapy to kill any remaining smaller tumor foci. The drug is administered directly into the bladder, which means that the side effects are less severe. Immunotherapy by administering BCG (tuberculin) is also helpful in preventing the bladder cancer from recurring.
In principle, however, regular follow-up examinations are advisable due to the high recurrence rates (= recurrence of the tumor) in bladder cancer. Shortly after the start of treatment, a check-up is carried out approximately every 3 months.
The treatment regime is different for advanced bladder tumors that have already grown into the muscle layer. In these cases, the bladder is completely removed and the adjacent lymph nodes are also removed, which are considered to be the preferred early metastasis sites.
The frequent consequences in men and women are libido disorders and urinary incontinence. Systemic chemotherapy is then absolutely necessary and has many side effects.
In recent years, systemic immunotherapy has proven to be very effective. Substances include prembulizumab or nivolumab . The tumor is to a certain extent unmasked by the medication and the patient's own immune system can take action against the tumor.
In some cases, attempts are made to restore continence by creating a new bladder(neobladder) from a section of the body's own small intestine or by creating an artificial urinary outlet (ileum condiut) with a collection bag.
The earlier bladder cancer is detected and the less advanced the disease is, the better the chances of recovery. Nevertheless, it must always be borne in mind that bladder cancer often recurs after just a few years.
Such recurrences, as well as the spread of metastases to other organs or the skeleton, reduce the chances of recovery and are generally associated with a poorer prognosis.