Active Surveillance for Intermediate-Risk Prostate Cancer

Photo by John Lund - Getty Images
Photo by John Lund - Getty Images. Photo by John Lund - Getty Images

People are becoming familiar with the modern approach to conceptualizing prostate cancer.  It starts by breaking down newly-diagnosed men into three broad categories invented by Dr. Anthony D’Amico: low, intermediate and high-risk. The D’Amico system is the best pathway to optimal treatment management since men with lower risk disease can receive milder treatment, or no treatment at all, and maintain normal survival rates.

 Men with higher risk disease generally benefit by undergoing treatment.

The rule of thumb is that low-risk men can monitor the disease and withhold therapy altogether unless tumor growth is detected during the monitoring process.  Men with high-risk disease typically undergo a year and a half of combination treatment with three forms of therapy:  seed radiation, IMRT, and hormone therapy.

Intermediate-risk disease presents a different problem.  It is the most complex of the risk types because over twenty treatment options exist.  For example, surgery, IMRT, seed implants, SBRT, Proton therapy, focal therapy and primary hormone therapy are all worthy of consideration.  Even more options become available when considering that these different treatments are often used in combination.  The plethora of treatment options is not random physician biases.  What we call “Intermediate-risk” is actually a very broad category with some cancers that are almost as harmless and low-risk.

 At the other extreme, some intermediate-risk cancers are just as dangerous as high-risk.  The terminology used to distinguish bad from good types of intermediate-risk are unfavorable and favorable.  For example, men who have intermediate-risk cancer at the “bad” end of the spectrum have a condition that we call unfavorable intermediate-risk.

Indicators that define an unfavorable type of intermediate-risk are multiple intermediate-risk characteristics such as a PSA over ten plus a Gleason of 4 + 3 (rather than 3 + 4).  Another indication of unfavorable intermediate-risk is when the cancer involves more than 50% of the biopsy cores.  Favorable intermediate-risk disease, on the other hand, is characterized only having a single intermediate-risk factor, such as a Gleason score of 3 + 4 = 7. All the other factors have to be low-risk.

Therefore, distinguishing between the favorable and unfavorable types of intermediate-risk disease is incredibly important for the treatment selection process.  Studies of men with the favorable type of intermediate-risk are indicating that these men are reasonable candidates for active surveillance rather than immediate treatment as described below.  This is an important new development considering that active surveillance has historically been reserved exclusively for men in the low-risk category.

One way to evaluate the question of whether or not newly-diagnosed men with favorable intermediate-risk can be safely watched is to extrapolate from the cure rates achieved after treatment.  If close to a 100% of men undergoing treatment are cured, the assumption is that their cancer was probably harmless and could have been safely monitored.  The results of one such study were presented at the 2015 American Society of Clinical Oncology’s Genitourinary Cancer Symposium.  Dr. Ann Raldow from Harvard reported on 6,500 newly-diagnosed men treated with radiation and hormone therapy at the Chicago Prostate Cancer Center between 1997 and 2013. The 6,500 men were separated into four categories: low, favorable-intermediate, unfavorable-intermediate, and high risk.  Eight years after treatment 820 men had died, 72 of them from prostate cancer.  Men in the favorable intermediate-risk category had the same high survival rates as men in the low-risk category.  Conversely, men in either the high-risk category or in the unfavorable intermediate-risk category demonstrated an increased mortality rate from prostate cancer.

Bottom line, men in the favorable intermediate-risk prostate category behaved just the same as men with low-risk.  Dr. Raldow’s analysis adds to the growing body of evidence that indicates that men with the favorable type of intermediate-risk prostate cancer are appropriate candidates for active surveillance and can forgo immediate treatment.

Continue Reading