Some thoughts about
PSA, and I'm going to put on my professional hat for a moment.
As an analytical chemist, there is a huge misunderstanding by the public about
what the numbers mean--especially what the pesky "<" means. With every analysis, there is a reality--usually unstated--that there is unavoidable error in the reading. This uncertainty, when it is expressed, is expressed in terms of a +/- value known as the limit of precision. By definition, it is 1 standard deviation of the statistical function that compares the "true" value to the range of measured value.
The "<" is similar: it is an expression that states that the method used, no matter what it is, is only sensitive to a specified value. It is possible to actually GET a reading that is below the sensitivity point--but it is considered meaningless because it may or may not be an artifact.
The key learning is that there are a number of different PSA tests out there, each has a defined sensitivity (Limit of precision), and a defined low limit of detection. There is a lot of published discussion about
what very low readings mean..and what the trigger for action should be. There are some serious researchers who suggest that ANY change above non-detectable, if confirmed by 2 tests some period of time apart, should be a call to action.
IMO, that really depends on how proficient the lab tech who is operating the machine is, and how well-maintained it is. If we keep lowering the theoretical limits (currently my numbers are reported as <0.006), then at some point we will be approaching the measurement of 1 molecule of the PSA antigen in a volume of blood. Is that meaningful? I'm not sure.
Age at Diagnosis: 56
RALP on 2/17/15, BJC St. Louis, Dr. Figenshau
58.5g, G3+4, 20%, 4 quadrants involved
PSA Non-Detect since April, 2015
My Story: www.healingwell.com/community/default.aspx?f=35&m=3300024