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.
