Most malignant bladder tumors originate in the urothelium, the epithelium that lines the inside of the bladder and other parts of the urinary tract. That is why we usually speak of urothelial carcinoma.
It is a disease that appears predominantly in older adults and is considerably more common in men. Presentation before age 40 is uncommon.
Key concept
Bladder cancer = think primarily of urothelial carcinoma.
It is the main modifiable risk factor.
The carcinogens contained in tobacco are absorbed, metabolized and then eliminated in the urine. Contact of the urothelium with these substances promotes the development of carcinogenic changes.
Therefore, in a smoker with hematuria, the possibility of a urothelial tumor must always be considered.
Occupational exposureProlonged exposure to certain industrial carcinogens is also associated with the development of bladder cancer.
It has historically been linked to workers exposed to substances used in certain chemical, dye and rubber industries. There may be a long latency period between exposure and the appearance of the tumor.
Other factorsThe following may also be associated:
Clinical pearl
Older patient + smoker + hematuria = rule out urothelial tumor.
Hematuria is the cardinal sign of bladder cancer. It is usually:
Non-muscle-invasive bladder tumors rarely cause pain.
Irritative symptoms may also appear, such as:
When these symptoms persist without a urinary tract infection to explain them, bladder disease should be considered, especially carcinoma in situ.
In advanced disease, anemia, weight loss, pain or a hypogastric mass may appear.
Key concept
The absence of pain is not reassuring in the setting of hematuria. Gross hematuria, especially in an adult with risk factors, requires urologic evaluation.
The evaluation integrates:
Medical history → risk factors → imaging → cystoscopy → transurethral resection → pathology.
CystoscopyCystoscopy allows direct visualization of the urethra and the interior of the bladder. It can detect small or flat lesions that may not be evident on imaging studies.
It also allows determination of:
Imaging studies allow evaluation of both the bladder and the rest of the urinary tract and are particularly important in the workup of a patient with hematuria.
Urine cytologyIt looks for abnormal urothelial cells shed in the urine. It is especially useful in:
It has lower sensitivity for low-grade tumors. A negative cytology does not exclude the presence of bladder cancer.
When a bladder tumor is identified, one of the fundamental procedures is transurethral resection of bladder tumor (TURBT). A resectoscope is introduced through the urethra and the lesion is resected endoscopically.
TURBT serves two fundamental functions:
Pathology will then determine:
For the medical student, one of the fundamental ideas is to distinguish between:
Non-muscle-invasive bladder cancerIt essentially includes:
The tumor invades the detrusor muscle. This difference profoundly changes prognosis and treatment.
To remember
Ta / T1 / CIS → non-muscle-invasive
T2 or higher → muscle-invasive
In addition to knowing how far the tumor invades, we must know its histologic grade. In simplified terms, we can speak of:
Low gradeThe cells retain greater resemblance to normal urothelium and generally show less aggressive biological behavior.
High gradeThey show greater atypia and cellular disorganization and have a higher risk of progression.
Stage = how far the tumor has spread. Grade = how aggressive its biology appears to be.
Carcinoma in situ, or CIS, deserves special consideration. It is a lesion that is:
It can go unnoticed during a cystoscopy or be mistaken for inflammatory changes.
Although it does not yet invade muscle, it should not be interpreted as a low-risk lesion. It has significant potential for progression and generally requires intravesical treatment.
Initial treatment is based on complete transurethral resection of the visible lesions. However, these tumors can recur and some may progress.
That is why, after TURBT, the patient's risk is assessed and a decision is made on whether intravesical treatment is needed.
Intravesical chemotherapyCertain patients can receive chemotherapy directly into the bladder. The goal is to reduce the risk of recurrence.
Intravesical BCGBCG triggers a local immune response against tumor cells. It is particularly important in certain high-risk tumors and in carcinoma in situ; it is used to prevent or delay progression of high-grade tumors, T1, and CIS.
Key concept
TURBT removes the visible tumor. Intravesical treatment aims to reduce recurrence and progression in selected patients.
When the tumor invades the detrusor muscle, we are dealing with a disease with a greater capacity for progression and metastatic spread. The patient requires local and distant staging.
In localized disease, a classic strategy consists of:
Neoadjuvant chemotherapy → radical cystectomy.
In selected patients, trimodal bladder-preservation strategies also exist, combining:
Maximal TURBT + chemotherapy + radiotherapy.
Medical students do not yet need to know all the drug regimens. What matters is understanding that muscle invasion completely changes the therapeutic approach.
Bladder cancer has a particular characteristic: it can recur after treatment. In addition, certain tumors carry a risk of progressing to higher-stage disease.
For this reason, patients require regular urologic follow-up, mainly with cystoscopy and, depending on risk, cytology and imaging. The intensity of follow-up depends on individual risk.
Key takeaways from this lesson
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