Tugs may mean that that he has had a couple of PSA tests 12 months apart. The second is higher than the first and he has used the difference to calculate how long it will take his PSA to double i.e. 44.1 months.
If this is the case the 44.1 months calculation has no real meaning as his possible PSA increase may well have been influenced by various factors (other than possible tumour).
However if he has been diagnosed with tumour and been treated 44.1 months (almost 4 years) is a very long doubling time indicating that any tumour is extraordinarily slow growing.
Post Edited (BillyMac) : 11/4/2015 2:32:29 PM (GMT-7)