Active Surveillance for Men with Intermediate Risk Prostate Cancer

BY MARK SCHOLZ, MD

People are starting to become familiar with the modern way of conceptualizing prostate cancer.  When men are newly diagnosed, they are split into three broad categories: Low-Risk, Intermediate-Risk and High-Risk. This system, which was invented by Dr. Anthony D’Amico, is helpful for the proper selection of optimal treatment; men with more favorable types of prostate cancer can receive milder therapy and still maintain normal survival rates.

As far as treatment selection is concerned, as a general rule of thumb, men with Low-Risk disease are encouraged to simply monitor the disease, withholding therapy altogether unless tumor growth is detected on subsequent testing.  At the other extreme, men with High-Risk disease typically undergo combination treatment with three forms of therapy: seed radiation, IMRT and hormone therapy, which is continued for a year and a half.

Treatment recommendations for men with Intermediate-Risk range widely from surgery, to the many types of radiation—IMRT, seed implants, SBRT and Proton therapy to focal therapy, as well as the alternative of simply giving hormone therapy by itself. This wide variety of treatment options is not merely a result of physician bias.  It turns out that the types of cancer that occur in the Intermediate-Risk category also vary widely.  At the “good” end of the spectrum, men with the favorable type of Intermediate-Risk disease have a condition that behaves more like Low-Risk while cancers men at the unfavorable end of the Intermediate-Risk spectrum have a condition that behaves more like High-Risk.

The indicators that define an unfavorable type of Intermediate-Risk disease are multiple intermediate characteristics rather than having a single Intermediate-Risk factor.  For example, it is considered unfavorable when the PSA is over ten and the Gleason is 4 + 3 (instead of 3 + 4) and there are more than 50% of the biopsy cores containing cancer.  At the other extreme are men with the favorable type of Intermediate-Risk disease. These men are characterized by having all the Low-Risk factors in combination with only a single Intermediate-Risk factor.

Making a proper distinction between the favorable and unfavorable types of intermediate risk disease can be monumentally important as it relates to treatment selection. Studies show that men with favorable Intermediate-Risk disease are potential candidates for active surveillance.  A recently published report at this year’s Genitourinary ASCO meeting bears directly on this issue:

In Abstract #82 from the meeting, authored by Ann Caroline Raldow from Harvard, 6500 newly-diagnosed men treated with radiation and hormone therapy at the Chicago Prostate Cancer Center between 1997 and 2013 were evaluated.  Dr. Raldow calculated their survival rate after treatment based on their risk category: low, favorable-intermediate, unfavorable-intermediate, and high. Eight years after treatment 820 men had died, 72 of them from prostate cancer. Men in the favorable Intermediate-Risk category had the same survival rates as men in the Low-Risk category.  Men in either the High-Risk category or in the unfavorable Intermediate-Risk category demonstrated an increased mortality rate from prostate cancer.

Bottom line, the cancer of men with the favorable type of Intermediate-Risk prostate cancer behaves the same as Low-Risk.  Dr. Raldow’s analysis provides further clinical evidence that men with the favorable type of Intermediate-Risk prostate cancer can forgo immediate radical therapy and embark on active surveillance.