SAN FRANCISCO – Two new U.S. studies involving more than 150,000 older men with prostate cancer are likely to add to the intense debate about the optimal treatment for early disease, especially the various radiation therapy options.

One study suggests that the newer intensity-modulated radiation therapy (IMRT) is more effective and less toxic than the older conformal radiation therapy. But it found that proton therapy, which is even newer, not only wasn’t more effective than IMRT but also had higher bowel toxicity.

The second study suggests that external beam radiation therapy (EBRT) is more toxic than both prostatectomy and brachytherapy. Also, EBRT was at least twice as expensive.

Dr. Paul L. Nguyen

Both studies used linked SEER (Surveillance, Epidemiology, and End Results) and Medicare data.

"We all love new technology, regardless of how much it costs," said Dr. Paul L. Nguyen in a discussion of both presentations at the Genitourinary Cancers Symposium. But third-party payers are increasingly seeking comparative effectiveness data to show that the benefits of newer therapies justify their higher expense.

"Whether you agree with the findings or not, these two provocative studies provide data that are going to shape the public’s thinking about the relative value of our treatments," added Dr. Nguyen of the Dana-Farber Cancer Institute in Boston.

"More work is needed from us as a field to generate the data [to prove] that our treatments are cost effective. And if we do not generate [these data], then third parties are going to increasingly dictate the treatments that we can and cannot offer."

IMRT Tops External RT Options

In the first study, Dr. Nathan C. Sheets and colleagues at the University of North Carolina at Chapel Hill analyzed data for 12,976 men who had localized prostate cancer and were diagnosed in 2002-2006. "We observed a rapid and nearly complete adoption of IMRT as the radiation treatment of choice for localized prostate cancer between 2002 and 2008," he noted.

Dr. Nathan C. Sheets

Results using propensity adjustment (to try to compensate for factors that might have influenced treatment choice) showed that with a median follow-up of 4.5 years, IMRT was superior to conformal radiation therapy in terms of a lower rate of additional cancer treatment, which is a proxy for effectiveness (2.5 vs. 3.1 events per 100 person-years; P less than .001), and which he proposed might be related to the ability to increase the radiation dose given with IMRT.

Billing claims data indicated that IMRT also had lower rates of bowel toxicity (13.4 vs. 14.7 events; P less than .001) and hip fracture (0.8 vs. 1.0 events; P = .006), but a higher rate of erectile dysfunction (5.9 vs. 5.3 events; P = .006).

Proton Therapy Adds Cost, Toxicity

In an additional analysis of 1,638 men that compared proton therapy vs. IMRT – the largest series of proton therapy to date – the former was no more effective, as assessed from receipt of additional cancer treatments. Furthermore, it had a higher rate of bowel toxicity (17.8 vs. 12.2 events per 100 person-years; P less than .001), Dr. Sheets reported.

02/15/12  

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FROM THE GENITOURINARY CANCERS SYMPOSIUM

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Vitals

Major Finding: In one study, the mean total cost per patient per year considering both the initial treatment and the treatment of any toxicity was $6,412 for EBRT – twice that for open prostatectomy, at $3,206, and more than twice that for brachytherapy, at $2,557 (P less than .0001).

Data Source: Data were taken from two SEER-Medicare studies among 14,614 men and 137,427 men aged 65 years or older who were treated for prostate cancer.

Disclosures: Dr. Sheets and Dr. Ciezki disclosed that they had no relevant conflicts of interest. Dr. Nguyen disclosed that he receives research funding from Varian.

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Radiotherapy Comparison Favors IMRT for Prostate Cancer