No treatment for prostate cancer proven superior

Patients who undergo complete prostate removal are less likely to experience urinary incontinence or other complications if the operation is done by an experienced surgeon in a hospital that does many of the procedures, according to a report funded by the Agency for Healthcare Research and Quality, part of the U.S. Department of Health and Human Services.

However, the new report concludes that scientific evidence has not established surgery or any other single treatment as superior for all men. The analysis compared the effectiveness and risks of eight prostate cancer treatments, ranging from prostate removal to radioactive implants to no treatment. An article based on the report is posted in the online version of the Annals of Internal Medicine.

'This report is a reminder that patient outcomes may vary according to treatment settings,' said AHRQ Director Carolyn M. Clancy, M.D. 'But this analysis also underscores a broader message: when it comes to prostate cancer, we have much to learn about which treatments work best, and patients should be informed about the benefits and harms of treatment options.'

The prostate gland, which is about the size of a walnut, is located just below the bladder. It makes and stores the liquid that carries sperm. In 2007, about 218,000 men were diagnosed with prostate cancer, and about 27,050 men died from the disease. The primary goals of treatment are to determine whether an intervention is needed to prevent death and disability and to minimise complications. Treatment choices often take into account a patient's age, race, ethnicity, health status, family history, patient preferences and how quickly the cancer is likely to spread.

The lifetime risk of being diagnosed with prostate cancer has nearly doubled to 20 percent since the late 1980s, due mostly to expanded use of the Prostate Specific Antigen (PSA) blood test. But the risk of dying of prostate cancer remains about 3 percent. Therefore, considerable overdetection and overtreatment may exist. The U.S. Preventive Services Task Force, a panel of outside experts convened by AHRQ that makes independent evidence-based recommendations, maintains there is insufficient evidence to recommend for or against PSA testing for routine prostate cancer screening. PSA tests can detect early-stage cancer when it is potentially most treatable but also lead to frequent false-positive results and identification of prostate cancers unlikely to cause harm.

AHRQ's new report, based on a review of 592 published articles, compared eight prostate cancer strategies: complete surgical removal of prostate and related tissue; minimally invasive surgery to remove the prostate; external radiation; radioactive implants; destruction of cancer cells through rapid freezing and thawing; removal of testicles or hormone therapy; high-intensity ultrasound; and no immediate treatment, also known as 'watchful waiting.'

The report, compiled by AHRQ's Minnesota Evidence-based Practice Centre, is intended to provide unbiased, evidence-based information so that patients, clinicians and others can make the best treatment decisions possible. Among its conclusions:

- Not enough scientific evidence exists to identify any prostate cancer treatment as most effective for all men, especially those whose cancers were found by PSA testing. However, more than 90 percent of patients reported they would make the same treatment decision again, regardless of the treatment they received.

- All treatment options cause health problems, primarily urinary incontinence, bowel problems and erectile dysfunction. The chances of bowel problems or sexual dysfunction are similar for surgery and external radiation. Leaking of urine is at least six times more likely among surgery patients than those treated by external radiation.

- One study showed that men who choose surgery over watchful waiting are less likely to die or have their cancer spread. The benefit appears to be limited to men under 65. However, because few patients in this study had cancer detected through PSA tests, it is unknown if this finding would apply to those whose cancers were detected through PSA screening. Another smaller study showed no difference in survival between surgery and watchful waiting.

- Among patients who choose surgery, urinary complications and incontinence are less likely if their surgeons performed more than 40 prostate removals per year.

- Surgery-related deaths, urinary complications and readmissions were lower and hospital stays were shorter in hospitals that performed more prostate removals.

- A lack of research makes it impossible to compare several treatments: rapid freezing and thawing (cryotherapy); minimally invasive surgery (laparoscopic or robotic assisted radical prostatectomy); testicle removal or hormone therapy (androgen deprivation therapy); and high-intensity ultrasound or radiation therapy.

- Adding hormone therapy prior to prostate removal does not improve survival or decrease recurrence rates, but it does increase the chance of adverse events.

- Combining radiation with hormone therapy may decrease mortality. But compared with radiation treatment alone, the combination increases the chances of impotence and abnormal breast development.

The report released, Comparative Effectiveness of Therapies for Clinically Localised Prostate Cancer, is the newest analysis from AHRQ's Effective Health Care program. This AHRQ program represents an important federal effort to compare treatments for significant health conditions and make the findings public. The Effective Health Care program also translates reports into plain-language guides for clinicians, patients and policymakers.