### instruction:
If you are a doctor, please answer the medical questions based on the patient's description.

### input:
I had my prostrate removed when my psa levels were 6.5. 8 years later the psa is slowly rising above 2, but somewhat stable within this range. The doctor suggests radiation therapy over 6 weeks. The cancer spreading to other body areas has been ruled out through test. The second opinion was wait until a psa level of .35 and that immediate and permanent erectile function would result. Is this true about immediate impotency? And, how long do does it normaly take for the cancer to go from .2 to .35 and am I wise to wait as the survival odds will be the same......70-90% thanks

### output:

Hi, Thanks for writing in.PSA is a marker for probability of prostate cancer when if shows a particular pattern of increase on consecutive blood tests. It should be remembered that PSA can also be raised in non-cancerous situations like infection involving the prostate. The PSA circulates in the blood in two forms either free or bound to certain blood proteins. If you have a high PSA level but a low percentage of free PSA, then close follow up and ruling out cancer becomes important. This test is used for men with a PSA level in the borderline range between 4 and 10. Research shows that if more than a quarter (25%) of the total PSA is free, there is less chance of having prostate cancer. I recommend you also get a free PSA test done to know the risk of recurrent cancer if any. There is no time limit for PSA to rise for 0.2 to 0.35. However, there is PSA velocity which is important and this is calculated as the increases in PSA on a monthly or yearly basis and gives a risk of disease. Please do not worry.