Nov 11th 2008

“Why is PSA Still Important”

Dr. Gerard Morton

Assistant Professor, Department of Radiation Oncology,
University of Toronto, Radiation Oncologist,
Toronto-Sunnybrook Regional Cancer
Centre and Sunnybrook and
Women's College Health Science Centre

The topic came about as a result of member request - admittedly it had been a while we had a talk
specifically on PSA. The closest talk focused on PSA was provided, several years ago, by the Director
of Dynacare Labs and that was from the perspective of PSA Lab Testing methodologies.

Dr. Morton opened his talk by explaining that PSA was a protein found in the seminal fluid and
manufactured by the prostate to keep the semen liquid. A small amount could get into the blood
stream and be measured as the PSA level. Recounting the history of PSA he described how it
was first discovered in the 1960's by Dr. Hara researching the field of forensic science as a
method for semen detection. On a more humorous note, PSA testing , for a while at least, found
applications in "Home Infidelity detection kits". Early researchers had also hoped to find some use
in contraceptives. It was during the early 80's ' that a link between PSA and Prostate Cancer was
observed that led to PSA test evolution.

Dr. Morton provided insights as to the structure, source and generation of PSA, the prostate
ducts, the mechanism by which it was passed from the prostate gland into the blood stream
and the significance of Free and Complexed PSA. During Prostate Cancer the Prostate
generated less Free PSA than normal and ratios of less than 10% free to total PSA suggested
a 50 % chance of finding cancer on biopsy whereas ratios of more than 20 % Free to total
PSA suggested only a 10 % chance of finding cancer on biopsy. He also clarified that PSA
could be elevated due to many reasons and that by itself a high PSA did not necessarily mean
prostate cancer and conversely that prostate cancer did not always necessarily imply an
elevated PSA. He discussed what was normal PSA, illustrating a PSA trend chart by age
for a sample population. The talk then went into many details of the role of PSA testing
in early detection, how by itself PSA had limited value in screening but became a useful tool
in early detection when combined with other indicators such as DRE, age, symptoms, race
and family history and its role in monitoring, prognosis and treatment response. Dr. Morton
described the different staging classifications, explained Gleason score, the prognostic
groupings and the different treatment options based on the risk group. He talked
about salvage therapy, illustrating the management of rising PSA after treatment
with many examples from real life.

A useful free tool developed by Sunnybrook with other collaborators and available for use
over the internet by anyone is the "Sunny brook Prostate Risk Calculator" .
Some members have requested a link to this tool - here it is:
http://prostatecancerinfolink.net/risk-prevention/sunnybrook-prostate-cancer-risk-calculator

We had an highly interactive Question and Answer session with many relevant questions coming forth.
The Q& A session provided as much if not more detail as the talk itself on a variety of PSA aspects

Overall the evening went extremely well for all despite the initial glitch of having been switched to a
much smaller room at an extremely short notice. On a brighter note we will be back to enjoying a
fully renovated floor in our usual room (# 2 upstairs) at the Tterry Miller from our December meeting
onwards.
We are pleased to provide links below to the Audio Recordings and Presentation Slides for this session.

AUDIO & SLIDES DOWNLOADS

AUDIO:

NO AUDIO AVAILABLE

SLIDES:

PSA_Morton