The standard is not clear. For me the drop to <0.1 was a six week deal, but I am not the norm. Because I had advanced disease I was tested three weeks out, then 5 then 6 and have had 7 tests since my surgery in February. Some I requested some scheduled. I was able to follow my drop from 13.7 pre-operative to undetectable. At my peak I was originally tested at 19.8. The next week it was 18.7, then the 13.7 just before biopsy. These are vast ranges and I wanted to know more about my physiological behavior. So I asked for the tests. And to be honest, I don't think Walsh is wrong and he is quoting the standard. My Oncologist does not agree with Walsh on this one. He tested right out of the gate. He stated that a drop of 50% per day was what he expected. But I have seen other posters here not drop that quickly, including myself. Here's how those tests went:
October 3, 2006: 19.8
October 10, 2006: 18.7
Biopsy December 12 (3+4=7 4 of 8 positive up to 80%)
Surgery February 16,2007
March 12, 2007: 0.9
March 18, 2007: 0.1
March 25, 2007: <0.1
Tests in April, May, July, and September have all been <0.1
Looking at my histogram, I was ably to determine that I was a 30% per drop after surgery. I am also lucky to have my advanced disease get down to zeros. Walsh was right but so was my oncologist. Six weeks is enough time and 3 months will be accurate.
Age 45 (44 when Dx)
Pre-op PSA was 19.8
Surgery on Feb 16, 2007
Post-Op Pathology was poor: Gleason 4+3=7, 4 positive margins, Stage pT3b (Stage III)
HT began in May, '07 with Lupron and Casodex 50mg
IMRT radiation for 38 Treatments ending August 3, '07
My PSA did drop out after surgery to undetectable. It has not returned and I will continue HT until January '08.
My Life is supported very well by family and friends like you all.