Ureteric cancer is a rare type of cancer that develops in the ureters, the thin tubes that carry urine from the kidneys to the bladder. Though uncommon, this disease requires careful attention and specialized care, as it shares characteristics with bladder cancer and can impact multiple parts of the urinary system.
Understanding Ureteric Cancer
Ureteric cancer, also known as urothelial cancer of the ureter or upper tract urothelial carcinoma, is a disease where abnormal cells grow in the ureters. The ureters are muscular tubes, each about 25 to 30 centimeters long, that connect the kidneys to the bladder. These tubes play a crucial role in the urinary system by transporting urine from the kidneys, where it is produced, down to the bladder for storage before being expelled from the body.[4]
The walls of the ureters consist of several layers. The innermost layer is called the urothelium or transitional epithelium, which is lined with special cells known as urothelial cells or transitional cells. These cells have a remarkable ability to stretch and change shape as urine flows through the tubes. Most ureteric cancers begin in this urothelial layer, which is why they are often called urothelial carcinomas or transitional cell carcinomas. This same type of cell lines the inside of the kidneys’ collecting areas (renal pelvis), the bladder, and the urethra, which explains why cancer can sometimes develop in multiple locations along the urinary tract.[4]
About 90 percent of upper urinary tract tumors are urothelial carcinomas. Less common types include squamous cell carcinoma, which accounts for approximately 10 percent of ureter cancers, and even rarer forms like adenocarcinoma.[3][4]
How Common Is Ureteric Cancer
Ureteric cancer is not a common disease. Transitional cell cancer of the renal pelvis accounts for only 7 percent of all kidney tumors, while transitional cell cancer of the ureter represents just 4 percent of upper urinary tract tumors.[19] Between 5 and 10 percent of all urothelial cancers occur in the ureter or renal pelvis and are classified as upper tract urothelial carcinoma. The vast majority of urothelial cancers, about 92 percent, develop in the bladder, while approximately 7 to 8 percent occur in the upper lining of the kidney.[2]
When ureteric cancer does occur, it primarily affects older adults. The disease usually appears in people over the age of 65, and it is more common in men than in women.[3] This age and gender pattern is similar to that seen in bladder cancer, which makes sense given the close relationship between the two conditions.
Who Is at Risk for Ureteric Cancer
Several factors can increase a person’s likelihood of developing ureteric cancer. Understanding these risk factors can help individuals and healthcare providers identify those who may need closer monitoring.
Smoking cigarettes is thought to be one of the most significant risk factors for ureteric cancer. Tobacco use is believed to be responsible for about half of all bladder cancers, and the same harmful chemicals that affect the bladder can also damage the cells lining the ureters.[8] The substances in tobacco smoke are filtered by the kidneys and pass through the urinary tract, where they can cause cellular changes that lead to cancer.
Having a personal history of bladder cancer substantially increases the risk of developing ureteric cancer. The cells lining the ureters are identical to those lining the bladder, so someone who has had bladder cancer may develop cancer in the ureters as well. Similarly, people diagnosed with ureteric cancer face an increased risk of developing bladder cancer later. Studies show that 22 to 47 percent of people with ureteral cancer will develop bladder cancer at some point in the future, and 20 to 25 percent of patients with bladder cancer will develop upper tract urothelial carcinoma.[2][8]
Occupational exposure to certain chemicals significantly raises the risk of ureteric cancer. Workers in industries that manufacture leather goods, textiles, plastics, and rubber products may be exposed to harmful dyes and chemicals, including substances called aniline dyes, which are known to be carcinogenic. Prolonged contact with these substances can lead to cellular changes in the urinary tract.[2][3]
Taking certain pain medications over a long period may also increase risk. One example is phenacetin, a pain reliever that was once commonly used but is now banned in many countries due to its connection to kidney and ureter cancers.[7]
People with an inherited condition called Lynch Syndrome have a markedly higher chance of developing upper tract urothelial carcinoma. Lynch Syndrome is an inherited cancer syndrome that increases the risk of several types of cancer, including colorectal and urinary tract cancers. It is estimated that 21 percent of patients with upper tract urothelial carcinoma have a variant of Lynch Syndrome.[2] Exposure to excessive radiation and genetic factors can also contribute to the development of this disease.
Recognizing the Symptoms
The symptoms of ureteric cancer can vary from person to person, and some people may not notice any symptoms in the early stages. However, as the tumor grows or if it is aggressive, certain warning signs may appear.
The most common symptom is blood in the urine, a condition known as hematuria. The blood may be visible to the naked eye, making the urine appear pink, red, or dark brown, or it may only be detectable under a microscope during a urine test. Blood in the urine does not always mean cancer, as it can be caused by infections, kidney stones, or other conditions, but it should always be evaluated by a doctor.[2][3]
Back pain or pain in the flank, which is the area on the side of the body between the ribs and the hip, is another frequent symptom. This pain may be persistent and does not go away with rest or typical pain relief measures. Some people also experience pain at the juncture where the ribs meet the spine.[2][3]
Changes in urination patterns can also occur. These may include painful urination, a burning sensation when urinating, feeling an urgent need to urinate frequently, or difficulty starting urination. These symptoms overlap with those of urinary tract infections, which is why proper medical evaluation is essential.[2][3]
General symptoms such as unexplained weight loss, extreme tiredness or fatigue, and sometimes the appearance of blood clots in the urine can also signal ureteric cancer. While these symptoms can be related to many other conditions, their presence warrants a thorough examination to rule out serious diseases like cancer.[3]
How Is Ureteric Cancer Diagnosed
Diagnosing ureteric cancer involves several steps and various tests. A healthcare professional will typically begin by asking about symptoms and performing a physical examination. However, because a mass or enlarged kidney often cannot be detected by touch, additional diagnostic procedures are necessary.[3]
Urine tests are usually among the first diagnostic tools. A simple urinalysis can detect blood in the urine, even when it is not visible. A urine cytology test examines a urine sample under a microscope to look for abnormal or cancerous cells. These tests are non-invasive and provide valuable initial information.[5]
Imaging tests create detailed pictures of the urinary tract and help doctors understand the size and location of any tumors. Several types of imaging may be used. A CT urogram or computed tomography urogram is a specialized CT scan that focuses on the urinary system. An MR urogram or magnetic resonance urogram uses magnetic fields to create detailed images. An intravenous pyelogram involves injecting a contrast dye into the bloodstream, which then travels to the kidneys and urinary tract, making them visible on X-ray images. Ultrasound may also be used to examine the kidneys and detect abnormalities.[3][5]
A procedure called ureteroscopy allows doctors to directly view the inside of the ureters. During this procedure, a thin, lighted tube with a camera attached, called a ureteroscope, is inserted through the urethra, passed through the bladder, and then into the ureters. This enables the doctor to inspect the ureter walls for tumors or abnormalities. If a suspicious area is found, a small tissue sample, or biopsy, can be taken during the same procedure. The biopsy is then examined under a microscope to determine whether cancer cells are present and, if so, what type and grade they are.[5]
Additional tests such as a cystoscopy, which looks inside the bladder, may be performed to check for signs of bladder cancer, given the close relationship between ureteric and bladder cancers.[9]
Information from these tests is used to assign a stage to the cancer. Staging describes how far the cancer has spread and helps guide treatment decisions. Localized cancer remains at its point of origin and has not spread beyond the ureter. Regional cancer has progressed into surrounding tissue or nearby lymph nodes. Metastatic cancer has spread to other parts of the body.[3]
Preventing Ureteric Cancer
While it is not always possible to prevent cancer, certain lifestyle changes and behaviors can reduce the risk of developing ureteric cancer.
Quitting smoking is the single most important step a person can take to lower their risk. Smoking is a major cause of many cancers, including those of the urinary tract. Although quitting can be difficult, support is available through medications, counseling, and support groups. Speaking with a doctor about strategies to quit can significantly improve success rates.[20]
Staying well-hydrated by drinking plenty of fluids, especially water, may help protect the bladder and urinary tract. Drinking six to eight glasses of water daily helps dilute potentially harmful substances in the urine and encourages frequent urination, which flushes out the urinary system.[20]
Eating a balanced diet rich in fruits and vegetables provides the body with essential nutrients and antioxidants that may help prevent cancer. A diet that includes at least five servings of fruits and vegetables each day, along with whole grains and lean proteins, supports overall health and may reduce cancer risk.[20]
For people who work in industries where they may be exposed to harmful chemicals, following safety guidelines, wearing protective equipment, and minimizing direct contact with carcinogenic substances can help reduce exposure and lower risk.
Regular medical check-ups and prompt attention to symptoms like blood in the urine or persistent back pain are also essential. Early detection of abnormalities increases the likelihood of successful treatment.
What Happens in the Body During Ureteric Cancer
Ureteric cancer begins when cells in the urothelium, the inner lining of the ureter, undergo changes that cause them to grow and divide abnormally. Normally, cells in the body grow, divide, and die in a controlled manner. When this process goes wrong, cells can begin to multiply uncontrollably, forming a mass or tumor.
The urothelial cells that line the ureters, renal pelvis, bladder, and urethra are designed to stretch and contract as urine passes through. However, when these cells become cancerous, they lose their normal function and begin to invade the deeper layers of the ureter wall. As the tumor grows, it can penetrate through the lamina propria, a thin layer of connective tissue, and into the muscularis propria, the thick muscle layer of the ureter.[4]
The depth to which the tumor has grown into the ureter wall is a critical factor in determining prognosis. Superficial tumors that remain on the surface of the urothelium are generally well-differentiated, meaning the cancer cells still resemble normal urothelial cells, and these tumors tend to have a better outlook. Deeply invasive tumors that penetrate through the ureter wall are usually poorly differentiated, meaning the cells look very abnormal, and these cancers have a higher risk of spreading to other parts of the body.[19][24]
If left untreated, ureteric cancer can spread beyond the ureter. Cancer cells may invade surrounding tissues and organs or enter the lymphatic system and bloodstream, allowing them to travel to distant sites such as the lungs, liver, or bones. This process is called metastasis. When ureteric cancer spreads to nearby lymph nodes or distant organs, it becomes much more difficult to treat.[3]
Because the cells lining the ureter are the same as those lining the bladder and renal pelvis, cancer can develop in multiple areas of the urinary tract. Upper tract urothelial carcinoma in the renal pelvis or ureter can lead to the development of bladder cancer over time. This is why people with ureteric cancer require ongoing monitoring of the entire urinary system.[2]