The bladder is an inflatable, hollow muscular organ situated in the pelvis. The main function of the bladder is to store urine until it is excreted from the body through the urethra. In a normal adult, it can hold up to 800 mL of urine. The walls of urinary bladder consist of mainly three layers: mucosa (made up of transitional epithelium cells), lamina propria (made up of connective tissue), and muscularis propria (made up of 3 layers of smooth muscle fibers).
Risk Factors for Bladder Cancer
What are the types of Bladder Tumors?
Urothelial carcinoma or transitional cell carcinoma (affecting transitional cells that constitute the innermost lining of the bladder, renal pelvis, ureters, and proximal urethra) is the most commonly encountered (more than 90-95% of all cases) bladder cancer. Bladder cancer mostly occurs in men and generally at a higher age.
What are the Symptoms of Bladder Cancer?
What are the Investigations for Diagnosis and Staging of Bladder Cancer?
What is the Staging of Bladder Cancer?
Staging for bladder cancer is called as TNM staging system. It helps in disease prognostication and choosing an appropriate treatment strategy.
The diagram below shows the various layers of the wall of urinary bladder, that includes epithelium, lamina propria, inner muscle layer and outer muscle layer, from inside to outside.
Tis – Carcinoma in situ is a flat tumor limited to the epithelium.
Ta – Papillary tumor that doesn’t go beyond the epithelium.
T1 – Tumor infiltrates beyond the epithelium into lamina propria.
T2a – Tumor infiltrates into the inner muscle layer of bladder wall.
T2b – Tumor infiltrates into the outer muscle layer.
T3 – Tumor infiltrates through the bladder wall into perivesical tissue.
T4 – Tumor infiltrates into the surrounding structures.
In males, it may infiltrate into the prostate gland, as shown in figure below.
And in females, it may infiltrate posteriorly into uterus.
Or antero-laterally to the pelvic or abdominal wall.
N1 – Involvement of one regional lymph node in true pelvis
N2 – Involvement of multiple regional lymph node in true pelvis
N3 – Involvement of common iliac lymph nodes
M1a – Involvement of non-regional lymph nodes beyond common iliac.
M1b – Inlvement of one or more distant organs such as liver, bones, lungs, peritoneum, etc.
Like in the figure below, disease has spread to liver, making it M1b.
And here, it has spread to both the lungs.
It may also present as peritoneal deposits.
What is the Treatment of Bladder Cancer?
Treatment of bladder cancer depends on the stage, type, unifocal/multifocal, performance status of the patient, along with other factors. But the final treatment decision is taken by the oncologist after clinical evaluation of the patient.
Localised Bladder Cancer Treatment
A hollow tube called as cystoscope is introduced through the urethra into bladder, to check for the location, number and size. It also helps to perform transurethral resection of the bladder tumor.
As shown in the figure below, deeper muscle layers have to be included in the biopsy sample.
Now the further treatment depends on T status of the disease (as discussed above).
Tis – Intravesical chemotherapy required in all cases
Ta – Intravesical chemotherapy or observation
T1 (Low Grade) – Intravesical Chemotherapy
T1 (High Grade) – Cystectomy (removal of the bladder)
T2 – Cystectomy and chemotherapy if preferred. But for non-cystectomy candidates, combination of chemotherapy and radiation therapy may be used.
Locally Advanced Bladder Cancer Treatment
Locally advanced bladder cancer is one that extends outside the bladder or involves regional lymph nodes.
T3 – Treatment is similar as discussed for T2 disease.
T4 – Depending on the extent of T4 disease, it may be treated with surgery and chemotherapy, or it may not be surgically resectable when it may require chemotherapy with/without radiation therapy.
It is usually treated with chemotherapy with/without radiation therapy.
Metastatic Bladder Cancer Treatment
When the disease has spread to distant body parts, chemotherapy or immunotherapy are the preferred treatment options. Other modalities like radiation therapy or surgery may be considered to palliation or relief of symptoms.
What is Cystectomy for Bladder Cancer?
Surgery is the treatment of choice for muscle-invasive and some higher stage bladder cancers that have not spread to distant body parts and can be completely removed.
Partial cystectomy can be performed, depending on location and number of tumor(s), which allows the patient to retain bladder function.
However, a radical cystectomy is generally required for higher stage disease, wherein the entire bladder and nearby lymph nodes are generally removed.In radical cystectomy, prostate and seminal vesicles are also removed in men, while the ovaries, fallopian tubes, uterus, cervix, and a small portion of the vagina are often removed in women.
What is Intravesical therapy for Bladder Cancer?
In this technique, drug is placed directly into the bladder using a catheter. It can produce local action without affecting other body parts.
Drugs like mitomycin, valrubicin, docetaxel, thiotepa, and gemcitabine can be given by this technique. Bacillus Calmette-Guerin (BCG) (a modified tuberculosis bacterium) can also be given by this technique, which acts by activating the body’s immune system to destroy cancer cells. The most common side effects associated with intravesical therapy is irritation/burning in the bladder.
What is the role of Intravesical BCG in Bladder Cancer?
A bacterial vaccine– Bacillus Calmette-Guérin (BCG) (generally used to prevent occurrence of tuberculosis) is used in preventing early-stage bladder cancer recurrence. BCG stimulates the immune cells to attack bladder cancer cells.
It is generally employed as intravesical therapy after transurethral resection of bladder tumor (TURBT) or after surgical resection of some early-stage, high-grade, non-muscle invasive bladder cancers to prevent recurrence.
Induction intravesical BCG therapy is usually given once a week for 6 weeks. Two or more rounds of BCG induction therapy may be employed with a treatment-free interval of 4 to 6 weeks. Maintenance therapy with a monthly BCG dosing for about 1 to 3 years may be employed in some patients with high risk of disease recurrence.
Is Immunotherapy an option for Bladder Cancer Treatment?
Following are the immune-checkpoint inhibitors currently approved treatment option for the advanced-stage bladder cancer in specific patient population:
Atezolizumab, an PD-L1 inhibitor, has been approved as the first-line therapy for patients with locally advanced or metastatic bladder cancer who are not eligible for any platinum-containing chemotherapy, regardless of the PD-L1 expression level.
Following immune-checkpoint inhibitors have been approved as the second-line treatment of locally advanced or metastatic urothelial cell carcinoma (most common type of bladder cancer) that has progressed on or after platinum-based chemotherapy: Pembrolizumab, Atezolizumab, Nivolumab, Durvalumab, and Avelumab.
These agents can be employed for the treatment of patients who have progressed within 12 months of neoadjuvant or adjuvant platinum-containing chemotherapy. The PD-L1 expression levels estimation is not a pre-requisite for employing these agents as second-line treatment.
What is the role of chemotherapy in Bladder Cancer?
Chemotherapy means treatment with anti-cancer drugs that kill or decrease the growth of rapidly growing cancer cells. It is considered to be the mainstay of treatment for advanced stage disease that has spread to distant body parts. In early stage of disease, it may be combined with other treatment options to accelerate the benefit achievement. As discussed above, it may also be given through intravesical route in some indications.
Best Bladder Cancer Specialist in Delhi
Dr Sunny Garg is a renowned Medical Oncologist in New Delhi with an experience of more than 6 years of treating bladder cancer patients. He has practiced in leading cancer hospitals in Delhi, and currently practicing at Manipal Hospital, Dwarka.
He has a vest experience of treating bladder cancer patients in all stages of disease. He is well versed with Immunotherapy and Chemotherapy for Bladder Cancer treatment and also general supportive care for patients. He works in close collaboration with surgical and radiation oncologists, oncopathologists, nuclear medicine, and genetic counselors for comprehensive cancer care for the patients.
Call +91 9686813020 for appointment.