GENITOURINARY DISEASE

Genitourinary disease involves disorders of the genital and urinary organs. These organs are involved in reproduction and urination, and include the external genitalia, kidney, bladder, ureter, and urethra in both sexes; the prostate in males; and internal genitalia, including the ovaries and the uterus in females. Genitourinary diseases can be classified as either benign or malignant. This division has important prognostic and therapeutic implications.

Benign diseases of the genitourinary system can be divided into developmental (genetic or congenital) and acquired disorders. Developmental disorders usually present in childhood, and, if not treated promptly, they may result in permanent damage. Examples include congenital obstruction of the urinary organs, defects of the bladder wall or the genital tract, and abnormal sexual differentiation. In most circumstances, early recognition and treatment in childhood is associated with normal lifestyle and social development. The advent of routine prenatal ultrasound has revolutionized the opportunities for intervention, and most disorders are now diagnosed and treated earlier than in the past.

Acquired disorders can be subdivided into benign tumors, stones of the urinary system, obstruction of the genitourinary system, infectious and inflammatory processes, traumatic disorders, and iatrogenic processes. Acquired disorders may also include dysfunction of the genitourinary organs. Examples include kidney failure; dysfunctional voiding, including urinary incontinence; impotency; and infertility.

Renal failure, the inability of the kidneys to function normally, may be acute or chronic. This condition has a variety of etiologies such as medical diseases (diabetes, hypertension), primary renal diseases, and urinary obstruction (prostate enlargement or cancer). These conditions may be reversible or irreversible. In the latter, also called end-stage renal disease, the kidneys do not function well enough to maintain life. In this situation, renal replacement treatment with dialysis or renal transplantation becomes necessary.

Acquired benign disorders, although not fatal in the majority of cases, may have a significant impact on the quality of life. Antibiotic and anti-inflammatory agents, along with early treatment, have improved outcome in infectious and inflammatory diseases. Resistant bacteria have emerged, however, and are an ongoing problem, especially in immune-compromised patients.

Stone disease, wherein bodies form in the urinary system (bladder, kidney, and ureter), is a common problem with an increasing incidence in industrialized countries. Stones are caused by genetic abnormalities, metabolic abnormalities, dehydration, dieting factors, and urinary tract infections. Simple dietary and behavioral modifications, along with new medications, can decrease the chance of recurrent stones. Therefore, metabolic evaluation may help to prevent stone formation and decrease morbidity. Minimal invasive approaches now allow most urinary stones to be treated without open surgery.

Obstruction of the urinary tract due to an enlarged prostate is a common health problem in older men. Management of this condition has moved from a primarily surgical approach to effective medical management. Early recognition of symptoms of urinary obstruction can avoid serious complications such as kidney failure.

Malignant disorders may involve any organ. The distribution of most malignancies, however, is age dependent. The most common example of a childhood malignant tumor of the kidney is the Wilm's tumor, which typically occurs between ages 2 and 5. Testicular cancer is most common in young men between 20 and 35 years of age. In contrast, the highest incidence of kidney cancer and bladder cancer is in adults between 60 and 70 years of age. Prostate cancer is the most common genitourinary malignancy in men and is the second leading cause of death due to cancer in men. The incidence of prostate cancer increases with age. Elevated levels of prostate-specific antigen (PSA) in the blood has been found to be a marker for prostate cancer, as cancer cells leak more PSA into the blood than do normal cells. Current data suggest that annual prostate cancer screening for PSA and digital rectal examination may translate into a decreased mortality rate from prostate cancer in the future.

There are many genetic, racial, environmental, and behavioral risk factors for genitourinary malignancies. Race and family history are strong risk factors for prostate cancer, with black men having the highest incidence and Asian men the lowest incidence in the United States. Early screening of black men and those with a family history of prostate cancer may improve outcome. Dietary fat has been implicated as an important risk factor for prostate cancer.

Kidney cancer is a relatively rare tumor and accounts for 3 percent of all adult malignancies. Certain types of kidney cancer are associated with inborn defects in specific genes, such as kidney cancers in patients with Von Hippel-Lindau syndrome. Epidemiological studies have incriminated tobacco as an etiologic agent. No other definite environmental or occupational factors have been identified.

Bladder cancer is three times more common among men than women, and it is the fourth most common cause of cancer in men. It is almost two times as common in white men as it is in black men. The incidence of bladder cancer increased approximately 50 percent in the second half of the twentieth century. The mortality rate has decreased, however, primarily in men. This suggests a difference in bladder cancer diagnosis, treatment, or disease characteristics between the sexes.

Genetic and environmental factors play an important role in the development of bladder cancer. Cigarette smoking is the most significant risk factor, and smokers have a fourfold higher risk. This risk correlates with the duration and quantity of smoking. Occupational exposure accounts for 20 percent of bladder cancer cases in the United States. Anyline dyes and other chemicals, especially aromatic amines, have been associated with bladder cancer. Occupations that involve working with these chemicals, such as automobile manufacturing and painting, have an increased risk of bladder cancer. Other etiologic factors for bladder cancer include chronic bladder infections, analgesic abuse, pelvic irradiation, and chemotherapy. Knowledge of these risk factors may aid in the prevention and detection of bladder cancer.

The incidence of testicular cancer has strong geographical and ethnic distribution. For example, African Americans have one-third the incidence of American whites and ten times that of African blacks. A history of undescended testis in childhood presents the highest risk. Regular self-examinations in high-risk population may result in early detection and improved outcome.

Urology also includes penile pathology, including erectile dysfunction (i.e., an inability to achieve or maintain an adequate erection for sexual intercourse). Male-factor infertility and urinary incontinence are other areas of genitourinary disease. Urologists are the physicians trained to diagnose and treat these and all other disorders of the organs related to reproduction and urination.

Bijan Shekarriz

Marshall L. Stoller

(see also: Colorectal Cancer; Ovarian Cancer; Prostate Cancer; Prostate-Specific Antigen [PSA]; Sexually Transmitted Diseases; Testicular Self-Examination; Urinalysis; Urine Cytology; Uterine Cancer )

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