Negative Surgical Margins and extra-capsular extension

[Guest guest]

Chuck --

I've re-titled the thread.

Thanks for the reference, and your accumulated wisdom.

One thing that I didn't know (from the Harvard document you referred to):

-----------------------------

What percentage of a prostate's surface do you actually evaluate in the lab?

GENEGA: Well, it depends on how the specimen is processed. Are you going to

submit the entire prostate gland for microscopic evaluation, or are you going to

put in three or four sections from both the right and left lobes? When you

submit the entire gland, people think you're evaluating every aspect of the

prostate, but you're not. (You will, however, see more of the surface area than

if the specimen is not submitted in its entirety.) When you slice the prostate

for routine, non-whole-mount sections, each slice ranges from 2 to 3.5

millimeters in thickness, but from each of those slices, the histology lab takes

slices that are only about 5 microns thick to make slides. [A human hair is 100

microns thick.] So there's actually a relatively large surface area that you

don't see. If you were to look at the entire prostate, that would mean looking

at hundreds of slides, and that's not done.

-------------------------------------

So a _sample_ of the margin is examined! And that can lead to " sampling error "

-- the pathologist doesn't look at the spot where the margin is positive!

So the sequence can be:

.. . . There's extracapsular extension;

.. . . The surgeon sees or feels it, and cuts a bit more around the prostate;

.. . . But the surgeon didn't get _all_ the cancerous cells;

.. . . The pathologist examines the post-surgery prostate,

.. . . finds the extra-capsular extension;

.. . . doesn't examine the particular part of the edge where

.. . . . there _is_ a positive surgical margin ( " sampling error " )

.. . .

.. . . The pathologist reports " extracapsular extension " (correct)

.. . . and " negative surgical margins " (incorrect).

And eventually, there's a recurrence of the PCa, started from those left-behind

cells.

It's a complicated world.

> >

> > I had robotic surgery done three months ago and following surgery I was

> > staged pT3a (everything negative except extracapsular extension present).

> > Now that 3 months have passed, I am now faced with the difficult decision

> > if/when to perform radiation treatment (adjuvant RT). The SWOG study, last

> > updated in 2009, seems to be the standard of care for post-surgery

> adjuvant

> > radiation (see http://www.aboutcancer.com/prostate_T3_0609.htm) and based

> on

> > this study, a 20% improvement in the recurrence rate was seen when

> radiation

> > was initiated 3 months after surgery.

> >

> > However, questions remain - ultrasensitive PSA measurement did not exist

> > when the original SWOG study began. Would a more appropriate strategy

> today

> > for initiating radiation therapy following surgery would be when a rise in

> > PSA is seen but at a much lower measureable PSA level, such as waiting

> until

> > PSA rises to 0.02, rather than radiating at 3 months even with an

> undectable

> > (<0.01) PSA? This would prevent unnecessary radiation of some fraction of

> > patients who's cancer was cured with surgery alone. The question, of

> > course, is whether radiation is equally effective when radiating at 0.02

> PSA

> > (which could be several years after surgery!) as it is at 3 months after

> > surgery.

> >

> > Have any studies been done or is there any supporting evidence for such a

> > strategy? I need to make a decision and at this moment, after seeing two

> > different well-respected radiation oncologists, the opinion is divided

> > between them.

> >

> > Here are my stats:

> >

> > Pre-surgery:

> > PSA = 4.9

> > Gleason 7 (3+4)

> > 6/12 cores positive, all on R lobe, 30%/80%/90% involvement

> > Palpable tumor on DRE

> > Extracapsular extension evident on endorectal MRI

> >

> > Post-surgery:

> > Seminal vesicles and lymph nodes negative (9 excised)

> >

> > Negative surgical margins

> >

> > Tumor extended from the apex to the base of the gland

> >

> > Established extraprostatic extension present in the right para-apex,

> > right mid and right para-basal areas of the gland

> >

> > Additional foci of prostatic adenocarcinoma, Gleason score 4+5=9 and

> > 3+3=6 are present in the right and left base, respectively

> >

> > Gleason 7 (4+3), tertiary pattern Grade 5

> > Perineural invasion present

> >

> >

> >

> > Any help or advice much appreciated!

> >

> >

> >

> > --- Rich

> >

>