Wow you revived this from the abyss. Yes I wrote about
this in 2008 when CTC by CellSearch was only experimental. My oncologist, Nick Vogelzang, was one of the researchers. He still is but the test has promising but limited use. We stopped testing me for it in 2009 when 4 consecutive tests came back at a zero. While the test could detect circulating tumor cells, it was limited in how the data could be used. Not all the patients who had detectable CTC's needed additional follow up over standard protocols.
There is a newer version of the CTC involving stem cells. CTSC is also by CellSearch and is believed to be more effective at determining who might need to be more proactive in their therapies. Here is that write by the researchers:jco.ascopubs.org/content/early/2011/03/16/JCO.2010.30.5151.abstract?sid=5cf518ea-1b36-4027-98cd-0e1271c18638
It looks more useful to the stage 2C and 3 guys at discovering circulating tumor stem cells what are predictable higher risk for disease progression. I have two guys in my group that are being tested with this test and both have progressing disease. I am not certain that even with this data that they would change their protocols as both have been through secondary HT therapies (Nilandron, DES, Keto and in one case Abiraterone) and chemotherapy with docytaxel and prednisone. They can however monitor the CTSC's and see perhaps earlier in treatment if the protocol they are on is reducing the number of CTSC's in the blood ~ a possible predictor if the treatment is working.
I spoke to Vogelzang hypothetically using one of the cases and he said that when and how to use the test can still be an issue. For example some treatments show a quick response and some show slow responses. The PSA may indicate a treatment is working while the CTSC show's no change. And vice versa. So by reacting to these indicators you may add another protocol while not knowing which one is working. Of course that is a mute point if neither are working.
I hope to see more study material and when this test can be effective in prostate cancer. It is my understanding that the test is also usable in breast and testicular cancers, with minor alterations of the test equipment. But still some controversy there as well.
Advanced Prostate Cancer at age 44 (I am 48 now)
pT3b,N0,Mx (original PSA was 19.8) EPE, PM, SVI. Gleason 4+3=7
Da Vinci Surgery ~ 2/16/2007
Adjuvant Radiation Therapy ~ IMRT Completed 8/07
Adjuvant Hormone Therapy ~ 28 months on Casodex and Lupron.