Question

write down a brief note on urinary bladder cancer?
Note: No plagiarism.

Answer 1

brief note on urinary bladder cancer

Answer:

Introduction:

The cancers arising from urinary bladder are called.urinary bladder cancers .The urinary bladder is a hollow organ in the human pelvis that stores urine The wall of the urinary bladder is made up of epithelial layer followed by connective tissue layer and muscle layer.The epithelial layer lining the urinary bladder is transitional cell epithelium and hence the cancers commonly arising from the urinary bladder are transitional cell tumors or urothelial cancers.

The urinary bladder cancers can be superficial or deep depending upon the invasion into the deeper structures in the wall of the urinary bladder and are hence are classified as

1.invasive cancers.

2.non muscle invasive cancers

Etiopathogenesis and predisposing/risk factors causing the urinary bladder cancers

• presence of the genetic factors such as loss of heterozygosity on chromosome 9 ;alterations in TP53 gene associated with invasive cancer.
• environmental exposure to toxins as seen in use of tobacco and smoking.
• occupational exposure to aromatic amines ,hydrocarbons, chemical dyes,heavy metals, petroleum products and other chemical carcinogens.
• use of arsenic based pesticides for long term.
• chronic infection cystitis, presence of bladder stones.
• presence of parasitic infections such as schistosoma haematobium commonly seen as a predisposing factor for squamous cell urinary bladder carcinoma.
• chemotherapy with chemotherapeutic agent cyclophosphamide
• Radiation therapy/ treatment to the pelvis.
• presence of indwelling Foley's catheter for long duration as seen in patients with spinal cord injury.

The pathogenesis of urinary bladder cancer is explained in the flowchart below

Risk factors such as chemical toxins, genetic mutations, smoking, chronic irritation------ stimulation of proliferative changes in the the urothelium----- formation of cancerous hyperchromatic cells with unregulated growth---- development of urinarybladder cancer

Types of urinary bladder cancers.

Carcinomas of the urinary bladder arise from the urinary epithelium while sarcomas arise from the connective tissue.

1. Carcinomas

These type of cancers arise from the urinary bladder epithelium.The different types are

a] Transitional Cell carcinoma---- about 90%-95% of the tumours.

These are the commonest types of urinary bladder cancers arising from the urothelium lining the urinary bladder.They may present as polypoidal growth protruding into the lumen of the urinary bladder or flat invasive growth limited to the epithelium or invading the muscle layers and hence are classified as polypoidal or flat superficial tumors or invasive tumors which invade the muscle layers of the urinary bladder.The treatment is chiefly surgical excision of the cancerous tissue followed by chemotherapy or radiotherapy in advanced cases.

b] squamous cell carcinomas.

These tumors are characterized by squamous cells which are flattened cells like those present in the skin.They make about 3 to 5% of the urinary bladder cancers.The predisposing factors for squamous cell carcinoma are

• presence of indwelling Foley's catheter for long duration.
• presence of bladder stones.
• presence of parasitic infection in the bladder, schistosoma haematobium.

  These cancers are generally invasive in nature and invade the deeper tissues.

c] adenocarcinomas

These type of cancers are similar to the tumors that are seen arising from intestinal epithelium and glandular organs making about 1% -2% of the urinary bladder cancers and are generally invasive in nature.

d] small cell carcinomas.

These are round cell tumors which make less than one percent of the urinary bladder cancers.These tumors originate from the neuroendocrine cells, grow quickly and are invasive in nature.They are commonly seen to be responding to chemotherapy.

2, Sarcomas

These type of cancers arising from the soft tissues and the muscle layers of the urinary bladder and are rare tumors of the urinary bladder .Rhabdomyosarcomas and soft tissue sarcomas are the tumors which arise from the muscle and soft tissue of the urinary bladder respectively.

Presenting signs and symptoms

Painless hematuria is the common is presenting symptoms in about 80 to 90% of the patients.

The other symptoms include dysuria, frequency,hesitancy and urgency of urination; dull aching /severe pain in the pelvis or in the rectal area. In the late stages, The patient may present with a palpable mass/ tumor in the lower abdomen in advanced tumours.Some cases may be asymptomatic and the cancer is discovered in the later/advanced stages.

Diagnosis  

The following diagnostic modalities are used to diagnose urinary bladder cancers.

1.cystoscopic examination of the urinary bladder with biopsy of the tumor with the histopathological work up of the tumor

Three types of tumors can be identified on histopathological work up.

• carcinoma in situ
• low grade non-muscle invasive tumors---- these make about 75 to 80% of urinary bladder cancers
• high grade muscle invasive tumors---- these are aggressive and metastatic in nature.

2. microscopic examination of the urine may reveal cancer cells.

3. CT scan/MRI of the pelvis and abdomen are performed in order to stage the disease and to check for the local invasion and presence of lymph node invasion

Treatment

Non invasive urinary bladder cancer

Trans urethral resection of the bladder tumor commonly referred to as TURBT followed by intravesical chemotherapy or intravesical BCG vaccine is the treatment of choice for the early stage urinary bladder cancers which are limited to the epithelial lining of the urinary bladder.

Invasive urinary bladder cancer

The treatment of muscle-invasive urinary bladder cancer is predominantly surgical.The surgical treatment consists of total cystectomy in females ;cystoprostatectomy in males with ureteral implantation,commonly performed in case of muscle invasive tumors. Bilateral pelvic  lymph adenectomy PLND may be performed in cases of the spread of the tumor to the pelvic lymph nodes followed by chemotherapy and radiation therapy in advanced cases. Anterior pelvic exenteration surgery and total pelvic exenteration surgery are the procedures performed in advanced tumors. Continent / non continent urinary diversion procedures are performed in addition to cystectomy for urinary drainage.

Metastatic urinary bladder cancer.

For metastatic/recurrent urinary bladder cancers, aggressive therapy is initiated.Radical surgery followed by use of chemotherapeutic agents such as Methotrexate,Vinblastine,Cisplatin and Gemcitabine and use of inhibitors of PD 1[Programmed cell death protein and its ligands ] PD L1 and PD L2 like Nivolumab ,Atelozolizumab, Durvalumab and Avelumab is required for the patient treatment.

Prognosis and follow-up.

Prognosis is good in very early tumours.However,the recurrence rates in bladder tumors are high and hence the patient is required to follow up regularly.The recurrent tumors/ metastatic tumors are treated by use of chemotherapy, immunotherapy and radiation therapy.