Tracks 1-5
DR TAPLIN: For a patient with T3 disease, if the first postoperative PSA level
is zero, then we tend to use surveillance rather than immediate adjuvant radiation
therapy, although we discuss that option with the patient.
A proportion of these patients will remain in remission, and most of the data
suggest that if you administer radiation therapy when the PSA level is low, the
response rate is good. So you’re probably not losing time, and you eliminate
overtreating patients who may not need salvage radiation.
If I am worried about a patient’s pathology, I might measure PSA levels more
frequently, maybe every three to four months for the first year or two. We like
to have a sense of the PSA doubling time, and we don’t want the PSA level to
rise above one.
Our practice has been aggressive in adding hormone therapy to salvage radiation,
with few relevant data available. It’s not common practice in the community,
but we feel it will be a benefit to induce cell death and a longer-term
remission. We initiate the hormone therapy around the same time that we
start the radiation therapy.
For patients with a low-risk PSA failure — that i s, t hey fail two or more years
after their primary treatment, their doubling time is low and their initial
pathology was relatively favorable — we feel comfortable using salvage radiation
alone, without hormones.
DR LOVE: Dave, how do you approach the patient with a positive margin?
DR CRAWFORD: The Southwest Oncology Group conducted a randomized
trial (SWOG -8794) that demonstrated a number of benefits associated with
adjuvant radiation therapy — in patients with positive margins, seminal vesicle
invasion or extracapsular extension — including a decreased rate of metastatic
disease and PSA failure (Swanson 2007; [1. 5 ]). At 12 and a half years, we don’t
see a difference in survival, but we suspect it will come.
Many people believe, based on the SWOG - 8794 trial, that radiation therapy
should be administered to these patients . As for combining radiation therapy
and hormone therapy, I prefer to watch and see what the radiation therapy
does and not color it with hormones.
DR LOVE: What’s your genera l approach when treating with adjuvant radiation
therapy? Is it immediate or delayed?
DR CRAWFORD: Even though the SWOG-8794 trial shows an advantage
to adjuvant radiation therapy, we don’t have a trial that compares adjuvant
therapy to delayed therapy to answer that question. Until recently, I’ve been in
favor of waiting because I believe we do overtreat some people. Now I believe
either approach can be considered.
DR LOVE: How would you feel about the TAX-3501 adjuvant trial (1.6) comparing
androgen deprivation with or without docetaxel for patients at high risk?
DR TAPLIN: I believe it would be a good trial for this patient. It’s based on a
Phase II trial we published in the Journal of Clinical Oncology a few months ago,
in which we treated approximately 62 patients with four cycles of docetaxel/
estramustine followed by 15 months of goserelin acetate and bicalutamide
(Taplin 2006; [1.7]). A proportion of the patients on that trial continue to have
an undetectable PSA level years after stopping the castration therapy.
We need to have this confirmed in the Phase III trial. We would hope that
a proportion of patients would experience significant benefit from an early
aggressive approach.
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