Urothelial Carcinoma: Anatomy, Epidemiology, Symptoms, and Treatment

Introduction:

Cancer that begins in the cells lining the bladder and urethra is called urothelial carcinoma, sometimes called transitional cell carcinoma. Most bladder malignancies begin in the urothelium or transitional epithelium, the bladder's deepest lining. Cancer may enter or pass through the bladder wall's deeper layers as it spreads. It may become more difficult to treat cancer as it progresses. Over time, the cancer may spread outside the bladder to nearby organs and lymph nodes. In most cases, bladder cancer progresses to the liver, lungs, bones, or lymph nodes.

What is Urothelial Carcinoma?

Urothelial carcinoma is a type of cancer that begins in the urothelium, the tissue lining parts of the urinary system. It accounts for about 90 percent of all bladder cancers and seven percent of all kidney cancers, including the ureter and renal pelvis. Kidney and bladder cancer caused by urothelial carcinoma has the same symptoms. These cancers can be easily treated and have similar prognoses if detected early. However, chances of recurrence are possible in both.

Urothelial cancer is of two main types:

• High-Grade Urothelial Carcinoma: This can be a life-threatening condition that can recur after treatment. It can spread into the lymph nodes, muscle layers of the bladder, and other body areas.

• Low-Grade Urothelial Carcinoma: It rarely spreads into the muscle layers or other body parts but can recur.

Anatomy of the Urinary System

Think of your urinary system as an efficient waste management team comprising kidneys, ureters, bladder, and urethra. They all work together to filter and remove liquid waste from your body. The abdominal and pelvic regions contain all the organs that comprise your urinary system.

• Kidney: The majority of people have two kidneys. Kidneys are organs situated below the rib cage and behind the belly area. This kidney clears toxins and other waste products from the body by producing urine collected in the renal pelvis in the middle of both kidneys. From this area, the urine drains through a tube called the ureter, which connects the kidney to the bladder. Each kidney is about the size of your fist. Daily, your kidneys filter between 120 and 150 quarts (113.6 and 141.95 liters) of blood, resulting in 1 to 2 quarts (0.95 and 1.95 liters) of urine.

• Ureters: Urine is transported from your kidneys to your bladder via these two slender tubes inside your pelvis. The length of each ureter is roughly 9 inches. Like the kidneys, the ureter and renal pelvis are lined by urothelial tissue.

• Bladder: Urine is stored in your bladder until you release it. It has the shape of a triangle balloon, is hollow, and is composed of muscle. As your bladder fills up, it gets bigger. Up to two cups (500 milliliters) of urine can be stored in most bladders simultaneously. The act of emptying your bladder is called peeing.

• Urethra: Urine is transported from your bladder out of your body via this tube. When you are not using the restroom, your urethra is kept closed by two sphincter muscles. To release urine, these ring-like muscles open and close. These muscles might weaken over time, making it difficult to maintain your pee.

Epidemiology of Urothelial Carcinoma

Urothelial cell bladder cancer accounts for about 90 percent of bladder cancer cases worldwide and is more common in wealthier countries. Chemical exposure, particularly industrial exposure and tobacco smoke, is closely associated with this subtype because of direct urothelial exposure. Beyond the urothelium, these tumors penetrate the bladder's muscle, serous layers, lamina propria, and submucosa. Furthermore, they may proceed directly to the uterus, vagina, urethra, and prostate, which are all close to the pelvic organs. Hematogenous spread typically leads to metastases to the liver, lungs, bones, and adrenal glands and is linked to a poor prognosis. In contrast, lymphatic metastasis happens via the obturator, presacral, iliac, and para-aortic lymph nodes.

What Causes Urothelial Carcinoma?

Although the precise etiology of bladder and kidney urothelial carcinoma is unknown, bladder cancer starts when there are changes in your bladder cells' DNA. When healthy cells would perish, the alterations instruct the cell to continue living and to reproduce quickly. Normal body tissue may be invaded and destroyed by the tumor formed by the aberrant cells. The aberrant cells may eventually separate and move throughout the body, a process known as metastasis.

Some of the lifestyle and environmental risk factors of urothelial carcinoma include:

• Smoking Cigarettes: Cigarette smoking increases the risk of cancers of the urinary system, such as urothelial carcinoma.

• Certain Chemical Exposure - Research indicates that those who work in environments that contain chemicals such as rubber, paint, leather, dyes, hairdressing supplies, and textiles are more likely to develop urinary system cancers, including urothelial carcinoma.

• Chronic bladder irritation is brought on by bladder catheterization (inserting a thin, flexible tube in the bladder) or recurrent UTIs (urinary tract infections).

• Exposure to other substances, including drinking water containing arsenic.

• Previous Cyclophosphamide chemotherapy.

• Genetic disorders, like Lynch syndrome, previous radiation therapy, including radiation to the prostate.

How Does Urothelial Carcinoma Affect a Person's Body?

Urothelial carcinoma affects a person's kidney and bladder in several ways. The abnormal urothelial cells start spreading from the inner lining of the bladder into the deeper layers and surrounding fatty tissues of the bladder. If left untreated, this cancer can grow through the bladder walls to their nearby lymph nodes and other areas of the body, including the liver, lungs, or bones. In the case of kidney cancer, the abnormal cells form tumors in the kidney, ureter, or renal pelvis. Kidney cancer can also spread to other tissues or organs.

Symptoms of Urothelial Carcinoma

Early Warning Indications to Look Out for

Sometimes, urothelial cancer is cunning and does not immediately manifest symptoms. However, blood in your urine is frequently one of the first indicators. If you spot this, it is important to see a doctor. If you see blood in your urine or any of the following symptoms, you should speak with a healthcare professional:

• Persistent soreness in the back.

• Weariness.

• Unaccounted-for weight loss.

• Discomfort during urinating (dysuria).

• A tumor or lump in the vicinity of your kidney.

• Mild fever.

Advanced Symptoms of Urothelial Carcinoma

The following are the advanced symptoms of urothelial cancer are:

• Bone pain.

• Swollen feet.

• Breathing difficulties or a persistent cough.

• Unknown loss of weight.

• Fatigue.

• Sleep disturbances.

How Is Urothelial Carcinoma Diagnosed?

The following techniques and tests are used to diagnose urothelial carcinoma:

• Urinalysis - This test checks the color of the urine and its contents, such as protein, sugar, blood, and bacteria.

• Urine Cytology - The doctor will examine the urine under a microscope to check for abnormal cells. Cancer of the bladder or ureter and kidney cancer can shed cancer cells into the urine. The urologist can check the bladder for anomalies by inserting a narrow, lens-equipped tube (cystoscope) through the urethra. This examination can be performed in the operating room or clinic if a transurethral resection is required.

• Resection of the Transurethral Lining - A resectoscope, a thin device with a wire loop, is sent through the urethra into the bladder to collect tissue samples for biopsy. A cystoscopy may also be involved in this procedure.

• Ureteroscopy - The doctor will use a narrow tube-like instrument containing a lens and a light to view the inside of the renal pelvis and ureter and to obtain tissue samples.

• Computed Tomography (CT) - The CT scan uses a computer linked to the X-ray machine to create detailed photos of areas inside the body. During the CT scan of the urinary system, an iodine dye is injected into the vein.

• Ultrasound - This procedure uses a high-energy sound wave that bounces off the internal organs or tissues and creates echoes. These echoes form pictures of the body tissues called sonograms. Doctors usually perform an abdominal ultrasound to help diagnose cancer of the ureter and renal pelvis.

• MRI (Magnetic Resonance Imaging) - Patients who cannot undergo a CT (computed tomography) urogram due to iodine allergies or impaired kidney function may find this imaging helpful test.

Importance of Early Detection in Urothelial Carcinoma

Bladder cancer survival improves at a lower stage (T2 or less), which is depending on grade and stage. Delays in diagnosis and treatment do affect the final result. Therefore, a screening program and early identification of bladder cancer are necessary.

What Are the Stages of Urothelial Carcinoma?

Urothelial cancer, the most common type of urinary bladder, can be invasive or non-invasive.

The stages of urothelial bladder cancer include:

• Stage I: The cancer has not spread to the bladder's primary muscle wall and is limited to the lining of the bladder or the connective tissue immediately beneath it.

• Stage II: The cancer has progressed to the bladder's muscular wall.

• Stage III: The cancer has progressed to the adipose tissue beyond the bladder muscle.

• Stage IV: Your bladder cancer has progressed to your lymph nodes, other organs, or bones.

Understanding Tumor Invasion and Spread

Medical professionals can also classify bladder cancer as muscle-invasive, noninvasive, or noninvasive.

• Noninvasive: This type of bladder cancer can simply affect the surface of your bladder, or it can be tumors in a tiny area of tissue.

• Non-Muscle-Invasive: Bladder cancer that has progressed deeper into the bladder without spreading to the muscles is non-muscle-invasive.

• Muscle-Invasive: This type of bladder cancer has spread into the muscles of your bladder wall and may have reached the tissues or fatty layers of organs that are not part of your bladder.

What Are the Treatment Options for Urothelial Carcinoma?

Different treatment modalities exist for urothelial carcinoma of the kidneys, bladder, ureter, and renal pelvis.

Bladder Cancer Management - Management of bladder cancer includes surgical intervention, chemotherapy, immunotherapy, radiation therapy, and targeted therapy. Surgical intervention includes the removal of tumors using high-energy electricity and burning them away in a process called fulguration.

Kidney Cancer Management - Doctors manage kidney cancer the same way they manage bladder cancer. However, additional treatments include surgery, cryoablation, and radiofrequency ablation. In surgical intervention, the doctor might remove parts of the kidney containing cancer. In some cases, even the entire kidney might be removed.

Ureter or Renal Pelvis Cancer Management - The surgeons will remove part of the ureter or renal pelvis containing the cancer cells.

Ureteroscopic Management of Urothelial Carcinoma

Uteroscopic management is considered the first-line treatment for low-risk disease and is being utilized increasingly due to increasing surgical experience and technological advances.

• A low-risk urothelial carcinoma is defined as a unifocal disease consisting of a tumor of less than 2 cm in size, low grade on ureteroscopic biopsy, low-grade cytology, and in cross-sectional imaging, no invasive aspect was seen.

• In recent years, the endoscope has transitioned from a diagnostic tool to a therapeutic aid in managing the upper urinary tract. The majority of bladder cancer patients with low-grade, early-stage disease are managed endoscopically by transurethral resection of the bladder tumor.

• Endoscopic management can be done through a percutaneous approach or a ureteroscopic approach.

• Using diagnostic ureterorenoscopy, patients with urinary tract disorders like benign bleeding lesions are being treated on a routine basis with excellent success rates. An upper urinary tract urothelial malignancy undergoes endoscopic diagnosis by a no-touch technique.

• During ureteroscopy, urothelial carcinoma can be visually differentiated from benign processes. Ureteroscopic tissue samples can provide specimens to differentiate inflammatory lesions from benign and malignant tumors in case the diagnosis is uncertain.

• Although the recurrence rate of upper tract lesions is ordinary, endoscopic management gives a 90 percent cancer survival rate for non-invasive upper tract urothelial carcinoma at 20 years in certain patients.

Surgical Treatment for Urothelial Carcinoma

Radial nephroureterectomy (RNU) is the gold standard for surgically treating upper tract urothelial carcinoma (UTUC) that extends from the ureterovesical junction to the renal pelvis. Nevertheless, when the ipsilateral intact kidney is removed following RNU, renal functional deterioration leads to morbidity.

Chemotherapy and Radiation Therapy for Urothelial Carcinoma

In radiation therapy, high-energy beams such as protons and X-rays destroy the cancer cells. A device that directs high-energy beams at cancer cells is used in radiation therapy for bladder cancer. It's similar to shining a very focused spotlight on the cancer to eradicate it. Radiation therapy and chemotherapy are occasionally used to treat bladder cancer in specific situations, such as when surgery is not desired or feasible.

Immunotherapy in Urothelial Carcinoma

The protein on some immune cells (called T cells) called PD-1 targets nivolumab and pembrolizumab. Usually, this protein helps prevent T cells from attacking other cells in the body. Blocking PD-1 can shrink some tumors or stop their growth by stopping the immune system from attacking the cancer cells.

Preventing Urothelial Carcinoma

Tips to Lower Your Risk

• Stay away from smoking; if you do not smoke, do not start. If you smoke, talk to your doctor about a quitting plan. It is possible that you can quit utilizing medicines.

• When around chemicals, exercise caution. Take all required precautions when working with chemicals to prevent exposure.

• A good amount of fruits and vegetables rich in antioxidants may reduce your chance of getting cancer.

Lifestyle Modifications for Prevention of Urothelial Carcinoma

• Exercise.

• Hydration.

• Keeping your weight in check.

• Routine examinations and screenings.

Prognosis of Urothelial Carcinoma

The malignancy known as urothelial carcinoma begins in the cells lining your kidneys, bladder, renal pelvis, and ureter. Even though the same kind of malignant cell causes different types of cancer, the expected outcome can be different. Think of it as different pathways with different possible destinations. As with many cancers, bladder cancer survival is increased by early detection and treatment. The National Cancer Institute (NCI) reported in 2018 that 96 percent of patients with early-stage cancer who underwent therapy were still alive five years following their diagnosis.

Conclusion

Urothelial carcinoma begins as abnormal cells in the tissue lining the kidney, bladder, renal pelvis, and ureter. This cancer causes 90 percent of bladder cancer and about 7 percent of kidney cancer, including cancer that affects the ureter and renal pelvis. Both kidney and bladder cancer have the same symptoms and prognosis. They are easy to manage. However, the chances of recurrence are high in both of these cancers. Ureteroscopy is now widely used to treat low-risk urothelial carcinoma and is thought to be the first line of treatment for this type of cancer. After treatment, people with bladder cancer typically need follow-up testing for years to screen for recurrence.

Key Notes from iCliniq:

A neoplastic development known as urothelial carcinoma (UC) damages the lining of the urinary canal from the distal urethra to the renal pelvis. It may result in incontinence, painful urination, or frequent urine. Tumor growth that irritates the bladder lining or blocks the urinary system can also increase the risk of infection, discomfort, and insufficient bladder emptying. Please contact our specialists at iCliniq if you are experiencing any problems.