PSA velocity is the rate at which your PSA level increases from year to year. This rate of change in PSA levels over time, can give crucial information to a doctor about your potential for cancer. A rapid increase in PSA or PSA doubling time can be a sign of a rapidly growing cancer.
How much should my PSA be changing?
Generally speaking, there is no specific normal or abnormal PSA level. The PSA is not a perfect diagnostic test, and as such we rely on other factors such as age, family history, medical history, and background to help us get a clearer picture of what is “normal” for each patient. The amount of PSA present in the blood tends to increase with increasing age. So what is normal for a 70 year old, may not be normal for a 40 year old. With that said, 4 ng/mL is often considered the upper limit of normal. Generally, the higher the PSA level, the more likely that cancer is present.
Physicians have suggested that a PSA velocity that is over 0.35 ng/mL per year is the cut off for a high PSA velocity. Therefore an increase of about .65 or .7 in PSA per year can be indicative of prostate cancer, and should be closely monitored and further followed up by a physician.
What else can a PSA tell me?
Prostate cancer effects millions of men each year, whether newly diagnosed or living with prostate cancer. Despite the amount of lives this cancer affects, the tools for diagnosis fall short. For this reason it is important to use the tools that we do have to their fullest capacity. PSA velocity is one such way doctors use the PSA to it’s fullest potential.
Some other PSA related evaluations can similarly give physicians added information about a man’s risk of prostate cancer. These include PSA density and percent of free PSA. The PSA density evaluates the relationship between the level of PSA detected and the size of the prostate. This helps assess elevated PSA’s in men with enlarged prostates, for example, who may have elevated scores due to the size of the prostate, but not comparatively to those with smaller prostates. Percentage of free PSA on the other hand is a measure of amount of PSA which circulates in the blood. The PSA can be identifies in two forms, attached to certain blood proteins or unattached, aka free. According to research, a low ratio of free PSA to total PSA can increase the risk of a prostate cancer diagnosis. Overall, men with BPH will have higher free PSA whereas those with cancer will have a higher proportion of attached PSA.