Cutting Through the Confusion on Treating Prostate Cancer (Op-Ed)

Dr. Louis Potters is an internationally renowned expert in the treatment of prostate cancer, with over 100 publications, book chapters, editorials and letters. He is professor and chairman of the Department of Radiation Medicine for the North Shore-LIJ Health System and Hofstra North Shore-LIJ School of Medicine, and the co-executive director for the North Shore-LIJ Cancer Institute. He contributed this article to Live Science's Expert Voices: Op-Ed & Insights.

Almost daily, the public is bombarded with new information about prostate cancer. Should doctors screen for it? And how should we treat it when we find it? Some ask if we should even treat it at all. Depending on your perspective, the answers remain elusive, even confusing.

A recent study from Sweden, published in the New England Journal of Medicine (NEJM), looked at whether men treated with surgery fared better than men never treated (instead prescribed to receive "watchful waiting"). The study confirmed most peoples' intuition: Treating prostate cancer cures more men over a 20-year period than not treating it at all. But while the data make sense, this study is valuable because it specifically looks at men with "meaningful" disease, or what today physicians would call intermediate or high-risk cancers.

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The patients in this study included men diagnosed before the Prostatic Specific Antigen (PSA) blood test was available, and all but 12 percent of the men had what doctors would today consider locally advanced disease. That means their cancers were identified based upon a palpable nodule noticed during rectal examination. At about 20 years from diagnosis, 28 percent of men not treated (the watchful-waiting men) died from prostate cancer, while 17 percent of those men who had surgery died from prostate cancer. That represents, of course, a significant difference in favor of surgery.

So how does this study fit into the blitzkrieg of data on prostate-cancer screening and treatment? Let's start with the U.S. Preventive Taskforce, which recommends against PSA screening. That group based its conclusion on data suggesting that screening cancer (or early discovery of cancer) was not associated with a decrease in overall prostate-cancer mortality. Therefore, this research suggested, early discovery was of no benefit.

But too many "meaningless" cancers defined as 'low-risk' cancers had diluted this data. Too many of these low-risk cancers have been treated without producing a benefit or an improvement in prostate cancer mortality, since low-risk cancer likely may do well without treatment.

However, suppose we screen for prostate cancer using the PSA test and when discovered, doctors managed those meaningless, low-risk cancers initially by observing the behavior of the disease and reserving treatment only for those that started to change to intermediate or high-risk cancers. But the meaningful cancers discovered by screening are treated right away. Well, that is exactly what the NEJM study suggests we should do in order to have a real impact on overall survival.

Therefore, if men are screened for prostate cancer with the PSA test, and if the test identifies meaningful disease, doctors now know that treatment is better. And for all those other men with meaningless cancers, early — and even possibly late — intervention may not be necessary at all, as this treatment appears to have limited effect on whether or not the cancer will prove deadly.

While this study compared surgery to watchful waiting, the data for radiation therapy as an alternative to surgery is equal — and therefore men that should be treated should consider either option equally.

The views expressed are those of the author and do not necessarily reflect the views of the publisher. This version of the article was originally published on Live Science.