Transitional Cell Carcinoma
Transitional cell carcinoma is a type of cancer that develops in the cells lining your urinary system, including the bladder, kidneys, and the tubes connecting them. Accounting for about 90% of bladder cancers, it can be highly treatable when detected early, though it frequently returns after treatment.
Table of contents
- What Is Transitional Cell Carcinoma?
- Other Names for This Cancer
- Where This Cancer Develops
- What Causes This Cancer
- Who Is at Risk
- Signs and Symptoms
- How Doctors Diagnose This Condition
- Treatment Approaches
- Outlook and Prognosis
- Reducing Your Risk
What Is Transitional Cell Carcinoma?
Transitional cell carcinoma, also called urothelial carcinoma, is cancer that starts in special cells called transitional cells. These cells line the inside of organs in your urinary system[1].
Transitional cells are unique because they can change shape and stretch without breaking apart. When your bladder fills with urine, these cells stretch to make room. When you empty your bladder, the cells shrink back down. This ability to change shape is why they’re called “transitional” cells[2].
This type of cancer accounts for about 90% of all bladder cancer cases in the United States. It’s the most common type of bladder cancer and also the most common cancer of the ureter (the tube that carries urine from your kidney to your bladder)[1]. However, only about 7% of kidney cancers are transitional cell carcinoma[1].
Urothelial carcinoma, Urothelial cancer, Transitional cell cancer
Where This Cancer Develops
Transitional cell carcinoma can develop in several parts of your urinary system. The urinary system includes your kidneys, which filter waste from your blood and make urine. It also includes the ureters, bladder, and urethra (the tube through which urine leaves your body)[2].
- Bladder
- Renal pelvis (center part of the kidney)
- Ureters
- Urethra
The renal pelvis is located at the center of each kidney. This area collects urine before it flows into the ureters, which are long tubes that connect your kidneys to your bladder. There are two kidneys, positioned on each side of your backbone, above your waist[2].
Because transitional cells line many different parts of your urinary system, you can sometimes develop tumors in more than one place. If you have this cancer in your bladder, you should also be checked for tumors in other parts of your urinary tract[3].
What Causes This Cancer
Medical researchers don’t know exactly what causes transitional cell carcinoma, but they understand what happens in the body. A healthy transitional cell changes or mutates and becomes a cancer cell. These cancer cells can multiply and form tumors. Without treatment, the cancer can spread to other parts of the body[1].
Transitional cell carcinoma is a clear example of cancer arising from environmental factors. The disease develops when certain changes affect how transitional cells in the urinary system function, especially how they grow and divide into new cells[2].
Urothelial carcinoma is closely linked to environmental carcinogenic influences. By far the most important cause is cigarette smoking, which contributes to approximately half of all cases. Chemical exposure, such as that experienced by workers in the petroleum industry and the manufacture of paints, pigments, and agrochemicals, is also known to increase risk[4].
Who Is at Risk
Several factors can increase your chances of developing transitional cell carcinoma:
Smoking is thought to cause about half of all bladder cancers. Cigarette smoke contains harmful chemicals that your bladder must filter. As the bladder works to remove these chemicals from your body, it becomes damaged. Smokers are three times more likely to get bladder cancer than non-smokers[4][6].
Age matters significantly. Most people diagnosed with this cancer are over age 65. It typically affects adults ages 65 and older[1][5].
Sex plays a role in risk. Men are four times more likely to get bladder cancer than women. Men are also twice as likely to develop kidney cancers[1].
Chemical exposure increases risk. People who work with certain chemicals used in dyes, rubber, leather, paint, textiles, plastics, and hairdressing supplies may have a higher risk of developing this cancer[1][3].
Previous bladder cancer creates additional risk. If you’ve had bladder cancer before, you’re at increased risk of developing transitional cell carcinoma in your renal pelvis and ureters[1][2].
Chronic conditions may contribute. Long-term use or misuse of certain pain medications, chronic urinary stone disease, chronic catheterization, and chronic infections have been associated with increased risk[4][3].
Family history appears to matter. People with family members who have had bladder cancer are more likely to develop the disease. Additionally, Lynch syndrome, an inherited condition, increases the risk of several cancers, including urothelial cancer[5][7].
Signs and Symptoms
Symptoms may not appear right away in the early stages of transitional cell carcinoma. As the cancer grows, symptoms develop[3].
Blood in your urine, called hematuria, is usually the first noticeable sign and the most common symptom. This is often the initial clue that something is wrong[1][4].
You should contact a healthcare provider if you notice bloody urine or experience other symptoms, including:
- Painful or frequent urination
- Pain or burning during urination
- Changes in urinary habits
- Back pain that doesn’t go away
- Persistent low back pain
- Cramps in your side or back
- A lump or mass in your kidney area (your side and back, between your ribs and hips)
- Extreme fatigue
- Unexplained weight loss
These symptoms can also be caused by conditions other than cancer, so it’s important to see your doctor for proper evaluation[1][3][5].
How Doctors Diagnose This Condition
Your doctor will use several tests to determine if you have transitional cell carcinoma. The process typically begins with a physical exam and detailed health history about any past illnesses and your health habits[3].
Urine tests are usually the first step. Your provider will perform a urinalysis on a urine sample to look for blood, protein, sugar, bacteria, or other abnormalities. They may also do a urine cytology test, which examines your urine under a microscope to check for cancer cells that have sloughed off the walls of the bladder or kidney[1][3].
Imaging tests help doctors see inside your body. You may need a CT scan (computed tomography), MRI (magnetic resonance imaging), PET scan, or ultrasound so your provider can see tumors inside your body. Your doctor might order a special test called an intravenous pyelogram (IVP), which uses a contrast dye that makes blockages in your kidneys, ureter, and bladder stand out on an X-ray[1][3].
Scope tests allow direct visualization. Your provider may use a scope with a light and lens to see inside your bladder, kidneys, or ureters. During a cystoscopy, a narrow tube is inserted through the urethra to examine the inside of the bladder. A ureteroscopy allows the doctor to look inside your ureter and renal pelvis. Tissue samples can be taken during these procedures to check for signs of disease[1][3].
If bladder or kidney cancer is suspected, your doctor may also order a biopsy, where a small piece of tissue is removed and examined under a microscope for cancer cells[3].
Treatment Approaches
Treatment for transitional cell carcinoma depends on several factors, including the cancer’s location, stage, and grade (how abnormal the cancer cells look), as well as your overall health[1].
Surgery is the main form of treatment for localized disease. For transitional cell carcinoma of the kidney and ureter, total removal of the ureter with a bladder cuff, renal pelvis, and kidney is often recommended to provide the greatest likelihood of cure. This procedure is called a nephroureterectomy[2].
For patients with low-stage, low-grade tumors, more conservative surgical approaches may be possible. Kidney-sparing management using ureteroscopy can be performed for certain patients. During this procedure, doctors use special instruments to remove tumors while preserving kidney function[12].
For bladder cancer, treatment may involve a transurethral resection, where the tumor is removed through the urethra without making an incision in the abdomen[10].
Chemotherapy uses drugs to kill cancer cells. It may be given before surgery (neoadjuvant chemotherapy) to shrink tumors, or after surgery (adjuvant chemotherapy) to kill any remaining cancer cells. Chemotherapy is also used for advanced disease or when the cancer has spread. The most common approach involves cisplatin-based combination chemotherapy[5][10].
Topical therapy can be used for certain patients. After surgery to remove bladder tumors, some patients receive intravesical therapy, where medication is placed directly into the bladder. This may include chemotherapy or immunotherapy with BCG (Bacillus Calmette-Guérin)[10][12].
Immunotherapy helps your immune system fight cancer. This treatment approach uses medications called immune checkpoint inhibitors and may be suggested for certain patients[1][4].
Radiation therapy uses high-energy rays to kill cancer cells. While its role in treating upper urinary tract transitional cell carcinoma is not well defined, some studies suggest adjuvant radiation therapy may improve local control after surgery for high-grade disease[12].
Targeted therapy is another treatment option that targets specific characteristics of cancer cells[5].
Outlook and Prognosis
When caught early, transitional cell carcinoma is highly treatable. These cancers are curable in more than 90% of patients if they are superficial and confined to the renal pelvis or ureter[15].
However, the cancer often comes back after treatment. Evidence suggests non-muscle invasive bladder cancers (making up approximately 70% of those diagnosed with urothelial carcinoma) have a high recurrence rate—up to 70% within two years of treatment[20].
The major factor affecting your outlook is the depth of cancer infiltration into or through the wall of the urinary tract at the time of diagnosis. Most superficial tumors tend to be well differentiated, while tumors that have grown deeper are likely to be poorly differentiated. Patients with deeply invasive tumors confined to the renal pelvis or ureter have a 10% to 15% likelihood of cure[15].
After treatment for upper tract transitional cell cancer, there’s a 2% to 4% chance of developing cancer in the opposite kidney or ureter. The risk of developing bladder cancer after having upper tract transitional cell cancer ranges from 30% to 50%[15].
Because of the high recurrence rates, regular follow-up care is essential. Your doctor will schedule frequent check-ups and tests to watch for any signs that the cancer has returned[20].
Reducing Your Risk
While you can’t prevent all cases of transitional cell carcinoma, you can take steps to reduce your risk:
Don’t smoke or quit if you do. Smoking is the single most important preventable risk factor. Although quitting can be tough, it will help you feel healthier overall and significantly reduce your risk. If you need help quitting, speak with your doctor about medications or other options[20].
Avoid harmful chemical exposure. If you work with chemicals used in dyes, rubber, leather, paint, textiles, or plastics, follow safety guidelines and use protective equipment to minimize exposure[1][4].
Stay hydrated. Drinking lots of fluids, particularly water, may lower your risk of developing bladder cancer. Try to drink six to eight glasses of water a day[20].
Eat a healthy diet. A diet high in fruits and vegetables may help keep your bladder healthy and lower the risk of developing various types of cancer. Aim to have at least five servings of fruits and vegetables every day, and include whole grains several times a day[20].
Exercise regularly. Regular physical activity helps reduce the risk of cancer recurrence. Only 30 minutes a day of moderate exercise can make a significant difference in your health[20].
