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A User's Guide to Cancer Treatment

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Science  27 Nov 2009:
Vol. 326, Issue 5957, pp. 1184
DOI: 10.1126/science.326.5957.1184

“Is my disease curable?” That's the first question patients usually ask after learning they have prostate cancer, says Patrick Walsh, a surgeon and urology professor at Johns Hopkins Medical Institutions in Baltimore, Maryland. “Then they want to know, ‘What are my options for treatment?’” Choose radiation or surgery—and risk severe side effects? Opt for no treatment—and risk having the cancer spread?

Often, there isn't a clear answer. Imaging scans may not accurately identify the amount of cancer in the prostate. Experimental data comparing different treatments are nearly nonexistent. “So you lay out the side effects,” Walsh says. “You lay out the fact that you don't know whether surgery or radiation is better. … It's a very humble conversation.”

Data slog.

A review team led by Timothy Wilt (seated, left) pored over data from more than 700 prostate cancer studies.

CREDIT: APRIL EILERS/VA MEDICAL CENTER, MINNEAPOLIS

More than 200,000 men in the United States are diagnosed with the illness every year, making treatment options a prime candidate for review, according to William Lawrence, a medical officer at the U.S. Agency for Healthcare Research and Quality (AHRQ). Lawrence oversaw a comparative effectiveness (CE) review on prostate cancer commissioned by AHRQ in 2005, one of 18 the agency has done.

Timothy Wilt of the Minneapolis VA Medical Center, the review's lead author, and eight colleagues compared the most popular treatment methods, including surgery, radiation, hormone therapy, and “watchful waiting.” They also looked at a few not-so-common options, such as cryotherapy, which rapidly freezes and thaws cancer cells to destroy them.

The study, which cost $500,000, followed a standard course laid out by AHRQ, guided by questions from a group of “stakeholders” representing patients, radiation oncologists, urologists, and primary-care physicians. The nine reviewers slogged through mounds of evidence from more than 700 studies, assessed the strengths of doctors and hospitals, weighed side effects, and evaluated outcomes. Data on outcomes and side effects were culled from patient databases, surveys, and clinical trials. They encountered hurdles along the way: Countless definitions of erectile dysfunction and urinary incontinence made side effects tricky to compare. Randomized, placebo-controlled trials were lacking. The team searched for patterns, which they painstakingly graphed as a massive scatter plot, the size of each dot relative to the size of the study.

In February 2008 they delivered their findings: No one treatment is superior. All have adverse effects. Fewer side effects developed among patients treated by surgeons and medical centers that had performed more surgeries. The reviewers also spotted a revealing pattern: Doctors are more likely to recommend the treatment they practice. Wilt says: “Surgeons recommend surgery, radiation oncologists recommend radiation therapy, and very few individuals recommend watchful waiting, even for men with relatively slow-growing tumors, despite the fact that evidence suggests that all three treatment options are quite acceptable. Both patients and providers would be better served by knowing this information and having it displayed and available to them.”

Strong differences.

An analysis of U.S. prostate cancer treatments by region showed that “watchful waiting” was least practiced in New England.

CREDIT: APRIL EILERS/VA MEDICAL CENTER, MINNEAPOLIS

Opinions of the review are mixed. Some say it provides important guidance to people struggling with complex decisions. AHRQ produced a pair of guides summarizing the review for doctors and patients. More than 15,000 people ordered the guides for the prostate cancer study, according to AHRQ. “Often, what happens when you get diagnosed with something is you're kind of shell-shocked and you want to read up,” says Jean Slutsky, director of AHRQ's Center for Outcomes and Evidence. These guides, she says, help patients organize their thoughts and understand the research.

Others say the prostate cancer review illustrates the limitations of CE research. Walsh, who has published his own book, Dr. Patrick Walsh's Guide to Surviving Prostate Cancer, says the AHRQ clinicians' guide provides information that a doctor should already know, and the consumers' guide is full of questions: “They did their best, but I don't find it terribly helpful in the treatment of my patients.”

Sean Tunis, director of the Center for Medical Technology Policy in Baltimore and an expert on CE research, agrees that the review fails to address some essential questions. It represents something that occurs commonly in CE research, Tunis says: “A lot of times people mistakenly think that you can do a systematic review of what's known, and you'll come to a conclusion on what's more effective or less effective, more expensive or less expensive. But most come to the conclusions this one did: The studies we'd like to have haven't been done.”

Studies to fill research gaps need to be funded faster and tackled more efficiently, Lawrence says: “That's one area where I think you'll see more from us in the future.”

  • * Jenny Marder is a writer in Washington, D.C.

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