Feb
18
PSA screening
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Dr. Richard Bevan-Thomas, UANT
The prostate-specific antigen (PSA) blood test is a useful marker to detect prostate cancer. In fact, a majority of men diagnosed with prostate cancer over the last 2 decades underwent a prostate biopsy because of an abnormally elevated PSA. Despite its obvious utility in diagnosing patients with early localized prostate cancer, many men have undergone repeat biopsies because of an elevated PSA with no evidence of prostate cancer. In addition, controversy surrounds the precise cutoff point in which men should undergo a biopsy. Traditionally, urologists recommended a prostate biopsy for men with a PSA greater than 4.0; however over the last several years this cutoff level has been challenged. There are now a number of factors involved in the decision tree for recommending a prostate biopsy for men. These include the age of the patient, the PSA velocity and the percent free PSA.
PSA is a protein that is responsible for liquefying fluid in the ejaculate and is a normal product of the prostate gland. All men with a prostate therefore will have some detectable level of PSA on a blood test. Patients with prostate cancer, however, usually have an elevated PSA level. PSA can be divided into a complex and percent free PSA. Prostate cancer has been associated with a lower percent free PSA and men with a low percent free PSA (less than 12%) have an increased chance of harboring a focus of cancer. The PSA can be elevated for other reasons besides prostate cancer including infection, inflammation, urinary retention and benign enlargement of the prostate. The only way to diagnose prostate cancer is to perform a prostate biopsy (routinely performed in the office setting under ultrasound guidance).
PSA as a screening tool for prostate cancer was first described in 1991 by Dr. Catalona who concluded that the PSA was more accurate than the traditional digital rectal exam. Currently, both the digital rectal exam and PSA are used together to evaluate men at risk for harboring a focus of prostate cancer. Although the PSA test is very helpful in diagnosing patients with prostate cancer at an early stage, the exact number which should trigger the need for a biopsy continues to be debated. The American Urologic Association recommends a prostate biopsy for patients with a total PSA greater than 4.0, a suspicious digital rectal exam or significant change in the PSA velocity (PSA increase of 0.75 ng/ml over 12 months).
A recent paper published by Dr. Moul and colleagues atDuke University addressed several of the issues regarding the PSA threshold and PSA velocity in the Journal of Urology in February 2007. In this study, 11,861 men were evaluated over a 2 year period. The investigators found that using a PSA cutoff value of 2.0 and a PSA velocity of 0.4 ng/ml per year for men aged 50 to 59 had a higher sensitivity of detecting prostate cancer than using the standard cutoff of 4.0 and the standard PSA velocity of 0.75 ng/ml per year. The team therefore concluded that PSA velocity and PSA cutoff levels could be decreased in younger men.The bottom line on the PSA controversy is that there are multiple factors involved in recommending a prostate biopsy for men. Younger men with a mildly elevated PSA may require an earlier biopsy and more aggressive surveillance than older men. In addition, PSA velocity continues to play an important role as well to detect patients with early localized prostate cancer to improve the chances for cure.
Dr. Richard Bevan-Thomas, UANT
Dec
13
Overcoming Hematuria Recovery from a common urologic condition
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Hematuria, or red blood cells in the urine, can present microscopically or grossly as visible discoloration. In either case, hematuria is abnormal, except in young females with urinary tract infections. Bleeding originates from anywhere along the urinary tract, including the kidneys, ureters, bladder, prostate, and urethra.
Blood in the urine is often not a sign of serious disease, but hematuria is sometimes a marker for infection, stone disease, urinary tract cancer, or bladder cancer. Viral infections of the urinary tract and sexually transmitted diseases, especially in women, may also cause hematuria.
Signs and Symptoms
Symptoms include abdominal pain; decreased force of urination, hesitance, or incomplete voiding; fever; frequent and/or painful urination; pain in the flank or side; and urinary urgency. Asymptomatic microscopic hematuria has many causes, including life-threatening lesions.
In women, urethral and vaginal examinations will rule out local causes of microscopic hematuria. A catheterized urinary specimen is indicated if a clean-catch specimen is unobtainable. In uncircumcised men, the foreskin should be retracted to expose the glans penis. If a phimosis is present, a catheterized urinary specimen may be required.
In gross hematuria, the urine is red, pink, or dark brown and may contain small blood clots. However, the amount of blood in the urine is not a reliable indicator of the patient’s condition. Reddish urine not caused by bleeding (pseudohematuria) can be caused by excessive consumption of certain foods or medications. “Jogger’s hematuria” results from minor bladder hemorrhaging during running.
Diagnosing the Condition
In microscopic hematuria, the amount of blood in the urine is so small that it can only be detected by microscope. The American Urological Association’s definition of microscopic hematuria is three or more red blood cells per high-power field on microscopic evaluation of urinary sediment from two or three urinalysis specimens.
When hematuria is suspected, a midstream urine sample is applied to a chemically treated strip to see if it changes color, indicating blood in the urine. A positive result necessitates further examination.
Laboratory analysis includes urinalysis and microscopic examination of urinary sediment. The urine is examined for protein — an indication of kidney disease — and any evidence of urinary tract infection. The number of red blood cells per high-powered field is determined and the shape of the blood cells are evaluated to determine the origin of the bleeding.
The point when bleeding occurs during urination may indicate the location of the discharge. Initial hematuria at the onset of urination points to the urethra or prostate in men. Total hematuria throughout urination may originate from the bladder, ureter, or kidneys. Terminal hematuria at the end of urination points to the bladder or prostate in men.
In patients with white blood cells in the urine, a urine culture is performed and a urinary cytology is used to locate abnormal cells. A blood test measuring serum creatinine is useful. Patients with significant protein in their urine, abnormally shaped red blood cells, or elevated creatinine levels need further evaluation for renal disease.
A complete urologic evaluation for hematuria includes x-rays of the kidneys and ureters. Traditional testing involves an intravenous pyelogram, where dye is injected into the blood and x-rays are made as the kidneys excrete the dye. Some physicians use imaging studies, such as a computerized tomography (CT) scan or CT urography.
Further Tests
When there is elevated creatinine or an allergy to x-ray dye, magnetic resonance imaging or retrograde pyelography can help evaluate the upper urinary tract. In retrograde pyelography, dye is injected into the ureters from the bladder, and x-rays are taken. After the initial tests, the patient empties the bladder and has a final x-ray.
However, none of these studies affords bladder evaluation. A cystoscopic evaluation is usually performed under local anesthesia using a flexible cystoscope, enabling examination of the inner lining of the bladder and urethra.
Significant proteinuria, red cell casts, renal insufficiency, or dysmorphic red blood cells in the urine in asymptomatic microscopic hematuria should prompt evaluation for renal parenchymal disease.
When no specific cause is identified, bladder and kidney stones, cancer, and other lifethreatening diseases can be ruled out. Other causes that remain may correct themselves, or the hematuria may remain idiopathic.
Following UP
In 10% of cases, no cause for hematuria is found. However, studies show that urologic malignancy is later discovered in 1% to 3% of patients with negative test results. Follow-up is then recommended.
When bladder cancer is detected using a uroscope, the cancerous cells are often scraped from the lining of the bladder without invasive surgery. With kidney cancer, surgical removal of the malignancy is possible in some cases; in others, removal of the entire kidney is required.
The American Urological Association suggests repeating urinalysis and urine cystoscopy at six, 12, 24, and 36 months. Immediate reevaluation with cystoscopy and repeat imaging should be performed in the case of gross hematuria, abnormal urinary cytology, or irritating urinary symptoms, such as pain with urination or increased frequency of urination. If none of these symptoms recurs within three years, no further urologic testing is needed.