Upper tract tumors develop in tissue in the kidneys that
collects urine (i.e., the renal pelvis) and the tubes that
carry urine from the kidneys to the bladder (ureters). Cancer
that originates in the upper urinary tract accounts for less
than 1% of cancers of the reproductive and urinary systems
(genitourinary tract). Upper tract tumors are often associated
with bladder cancer.
Types
More than 90% of renal pelvis tumors develop in surface lining
cells (transitional epithelial cells). This type is called
transitional cell carcinoma (TCC). TCC often develops in
multiple areas of the upper urinary tract.
Fewer than 10% of renal pelvis tumors are squamous cell
carcinomas, which develop in flat surface cells that line the
renal pelvis. Adenocarcinoma, which develops in glandular
cells, is extremely rare. These types of renal pelvis tumors
are associated with inflammation caused by chronic urinary
tract infections and kidney stones.
Incidence and Prevalence
According to the American Cancer Society, incidence of upper
tract tumors is about 1-2 cases per 100,000 people each year.
Renal pelvis tumors are more common in men and in Caucasians.
Peak incidence occurs in the 60- to 70-year age group. The
highest incidence is in Balkan countries such as Bulgaria,
Greece, Yugoslavia, and Romania.
Upper tract tumors occurring on both sides (bilateral) account
for less than 2% of cases.
Causes and Risk Factors
The cause of upper tract tumors is unknown. A personal history
of bladder cancer is the primary risk factor. Smoking
cigarettes is also a major risk factor. Smoking may contribute
to as many as 60-80% of cases. Other risk factors include the
following:
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Age
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Balkan
descent |
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Chronic
urinary tract infections |
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Family
history of transitional cell carcinoma
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Genetic
mutation of the p53 gene |
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Overuse of
analgesics that contain phenacetin
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Recurrent
kidney stones |
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Use of
chemotherapy drugs cyclophosphamide and ifosfamide
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People who
work in chemical, petroleum, aniline dye, and plastics
industries, and those exposed to coal, tar, and asphalt,
also have an increased risk for upper tract tumors.
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Consuming
more than seven cups of coffee a day may slightly increase
the risk for the condition. |
Signs and Symptoms
Blood in the urine (hematuria) is the most common symptom.
Hematuria may be visible to the naked eye (gross) or visible
upon examination with a microscope (microscopic). Other
symptoms include bladder irritation, constipation, and pelvic
pain.
Diagnosis
Diagnosis of upper tract tumors requires physical examination
to detect tumors that are able to be felt with the fingers
(palpable), laboratory tests, and imaging procedures.
Laboratory tests include the following:
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Urinalysis
(to detect microscopic hematuria)
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Urine
cytology (to examine tissue cells found in urine for
abnormalities) |
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Urine culture
(to rule out urinary tract infection)
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Imaging
procedures include computed tomography (CT scan) and
intravenous pyelogram (IVP). CT scan uses x-rays to
provide images of the urinary tract. It is used to
distinguish kidney stones from upper tract tumors and to
determine if a tumor has spread (metastasized).
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Intravenous
pyelogram is performed to detect a blockage in the urinary
tract. In this procedure, a contrast agent (radiopaque
dye) is administered intravenously and x-rays are taken as
the dye moves through the urinary tract.
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If an upper tract tumor is suspected,
ureteroscopy and brush biopsy may be performed. Anesthesia is
administered and a thin, telescope-like tube with a tiny
camera attached (ureteroscope) is inserted into the ureter to
allow the physician to detect abnormalities.
In a brush biopsy, a catheter is inserted
into the ureter and tissue samples of suspicious lesions are
taken using a small brush. The cells are examined under a
microscope and the disease is staged if cancer is detected.
Treatment
The preferred method for treating most upper tract tumors is
surgical removal of the kidney, ureter, and a portion of the
bladder (nephroureterectomy). Partial removal of the ureter is
not often recommended because there is a high risk for
recurrence in the remaining portion.
Tumors that are confined to the lower third of the ureter may
be treated using surgical removal of the ureter (ureterectomy)
and surgical removal of regional lymph nodes (lymphadenectomy).
Patients with only one kidney and those with reduced kidney
function, bilateral tumors (i.e., occurring on both sides),
and metastatic upper tract tumors are not candidates for this
procedure. These patients are treated using topical
immunotherapy or chemotherapy.
Topical immunotherapy, also called biological therapy, is used
to enhance the immune system’s ability to fight cancer. In
this treatment, BCG, a vaccine derived from the bacteria that
causes tuberculosis, is infused through a catheter into the
upper urinary tract to stimulate the immune system to destroy
cancer cells.
Side effects include inflammation of the bladder (cystitis),
inflammation of the prostate (prostatitis), and flu-like
symptoms. If high fever (over 101.5 °F) occurs, it may
indicate that bacteria have entered the bloodstream (called
bacteremia, a life-threatening condition that requires
antibiotic treatment).
Chemotherapy is used after surgery to treat metastatic upper
tract tumors and as primary treatment for inoperable tumors.
Chemotherapy involves using toxic drugs to destroy cancer
cells. A combination of methotrexate, vinblastine,
doxorubicin, and cisplatin (M-VAC) is often used for upper
tract tumors. These drugs may be injected, administered
intravenously, or taken in pill form. Chemotherapy has many
side effects, some of which are severe.
Radiation may be used to reduce pain (called palliative
treatment) for upper tract tumors.
Prognosis
The prognosis for upper tract tumors depends on the stage of
the disease at diagnosis. Untreated upper tract tumors are
fatal. Tumors of the renal pelvis have a better prognosis than
tumors of the ureter.
Prevention
Upper tract tumors cannot be prevented. Avoiding smoking and
eliminating other known risk factors as well as chronic UTI
and kidney stones can help prevent the condition.
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