Key Takeaways

• More than 90% of urinary tract cancers are urothelial carcinomas arising from transitional cells lining the urinary system.
• Cigarette smoking is the leading risk factor for bladder cancer, significantly increasing risk compared to nonsmokers.
• Hematuria (blood in the urine) is the most common warning sign and requires prompt medical evaluation.
• Treatment varies by stage and type, ranging from endoscopic tumor removal to intravesical therapy, radical surgery, chemotherapy, or radiation.
• Recurrence rates are high in certain bladder cancers, making long-term surveillance such as regular cystoscopy essential.

A Southern California urologist based in Bakersfield, David Horovitz, MD, leads David Horovitz, MD, Inc.: General Urology, Endourology, and Minimally Invasive Surgery. He diagnoses and treats disorders involving the kidneys, bladder, prostate, urethra, and male reproductive organs, including urinary tract infections, kidney stones, prostate enlargement, infertility, erectile dysfunction, and cancers of the urinary system.

Trained at the University of Western Ontario and the University of Toronto, he completed an Endourological Society accredited fellowship in minimally invasive and robotic surgery at the University of Rochester Medical Center. A fellow of the Royal College of Physicians and Surgeons of Canada and a diplomate of the American Board of Urology, he incorporates advanced laparoscopic and robotic techniques into practice.

His clinical background and research experience inform his approach to evaluating and managing urothelial and related malignancies.

Types and Risk Factors of Urinary System Cancers

Urothelial malignancies refer to cancers that occur within the kidneys, ureters, bladder, and urethra. The kidneys remove water and waste from the blood and generate urine that collects in the kidney’s renal pelvis before being discharged via the ureter to the bladder. Flat when empty, the bladder balloons as urine fills it, causing an urge to urinate. Another tube, the urethra, carries urine out of the body.

Urothelium, consisting of transitional cells, extend from the renal collecting tubules in the kidney to the urethra and line the urinary tract. These highly specialized cells have varied shapes and varying degrees of elasticity. Any part of the urothelium may convert into cancer. More than 90 percent of urinary tract cancers are urothelial carcinomas, which previously went by the name transitional cell carcinomas (TCC). Rarer tumor types include small cell carcinoma, squamous cell carcinoma, and adenocarcinoma. Some neoplasms are benign and non-cancerous.

Risk factors for the development of these types of cancers depend on the specific cancer site and type. Cigarette smoking is the most important risk factor for the development of bladder cancer, with half of those who contract bladder cancer attributed to past or present smoking. Smokers have a risk of developing bladder cancer two or three times higher compared to nonsmokers. Occupational exposure to aromatic amines such as benzidine and beta-naphthylamine is the root of as many as one-fourth of bladder cancer cases. Also implicated are the excessive use of drugs that contain phenacetin (a pain reliever), prior pelvic radiation, chronic infection, arsenic exposure, and Schistosoma haematobium infection.

The bladder has both squamous cells urothelial cells lining it, with urothelium implicated in 90 percent of cancer growths, and squamous cells in eight percent. Those cancers limited to cells lining the first two layers of the bladder are known as non-muscle invasive bladder cancer. Those starting in the superficial layers may spread deeper through bladder’s lining and may progress to involve the bladder’s muscular wall and even the fat surrounding the bladder wall, having significant implication on both prognosis and treatment options.

Both sexes may experience the spread of bladder cancer to the abdomen, with lymph nodes often affected. Women may also experience local invasion of bladder cancer to nearby organs such as the uterus and vagina, while men can experience invasion to the prostate gland.

Those with urinary tract cancer frequently experience blood in the urine, also known as hematuria. When this occurs, further diagnostic evaluation is required to eliminate other conditions with similar symptoms, such as urinary tract infection and kidney stones. Bladder cancer may also present with lower urinary tract symptoms such as urinary frequency and urgency as well as pain and burning with urination. Urothelial cancer of the ureters and renal pelvis (upper tract urothelial carcinoma) may cause blockage of the ureters leading to flank pain, nausea and vomiting while others (~15%) are asymptomatic with tumors found incidentally on imaging studies performed for other reasons. Distant spread may cause back pain, unexplained weight loss, swelling of the legs and ankles, chronic cough and fatigue.

Cancers strictly confined to the urethra are very rare, with risk factors being over 60 and having a history of bladder cancer. Sexually transmitted infections such as HPV, as well as chronic urinary tract infections, also raise risks. While urethral cancers invade locally, they can be aggressive and spread to adjacent tissues.

Treatment options for those with urinary tract cancers also vary and depending on the type of cancer. Superficial tumors of the bladder are often treated with outpatient endoscopic resection. Higher risk lesions may be treated with instillations of BCG or chemotherapy to try to prevent recurrences and progression. For those who have the highest risk disease, treatment may consist of radical surgery with or without chemotherapy although radiation remains an option in some cases. Tumor recurrence is not uncommon, with 50 percent of high-grade non-muscle invasive urothelial carcinoma recurring. Thus, for patients who have a history of bladder cancer, regular surveillance cystoscopy is extremely important.

FAQs

What are urothelial cancers?

Urothelial cancers are malignancies that arise from transitional cells lining the kidneys, ureters, bladder, and urethra.

What is the main risk factor for bladder cancer?

Cigarette smoking is the most significant risk factor, accounting for approximately half of bladder cancer cases.

What symptoms should prompt medical evaluation?

Blood in the urine, urinary frequency or urgency, pain with urination, flank pain, and unexplained weight loss warrant further assessment.

How are early-stage bladder tumors treated?

Superficial tumors are commonly managed with outpatient endoscopic resection, sometimes followed by intravesical BCG or chemotherapy.

Why is long-term follow-up important after bladder cancer treatment?

Because recurrence rates can be high, regular surveillance cystoscopy is critical to detect and manage new tumors early.

About David Horovitz, MD

David Horovitz, MD, is a Bakersfield, California based urologist specializing in general urology, endourology, and minimally invasive surgery. He treats conditions affecting the kidneys, bladder, prostate, urethra, and male reproductive organs, including urinary system cancers and kidney stones. Dr. Horovitz completed his medical degree at the University of Western Ontario and advanced fellowship training in laparoscopic and robotic surgery at the University of Rochester Medical Center. He is a fellow of the Royal College of Physicians and Surgeons of Canada and a diplomate of the American Board of Urology.