The formula to calculate the PSA velocity is:
\[ \text{PSA Velocity} = \frac{\text{PSA2} - \text{PSA1}}{\text{Time}} \]
where \( \text{PSA Velocity} \) is the rate of change in PSA levels over time, \( \text{PSA1} \) is the initial PSA level, \( \text{PSA2} \) is the subsequent PSA level, and \( \text{Time} \) is the duration between the two PSA tests, usually in years.
PSA velocity is a term used in medicine to refer to the rate at which the level of prostate-specific antigen (PSA) increases in a man's body over time. PSA is a protein produced by the prostate gland and its level can rise due to various conditions, including prostate cancer. Therefore, monitoring the PSA velocity can help doctors detect prostate cancer at an early stage and monitor the effectiveness of treatment.
Let's assume we have the following values:
Step 1: Subtract the initial PSA level from the subsequent PSA level:
\[ \text{PSA2} - \text{PSA1} = 4.0 - 2.5 = 1.5 \]
Step 2: Divide the result by the time duration:
\[ \frac{1.5}{1} = 1.5 \]
Therefore, the PSA velocity is \( 1.5 \) ng/mL per year.
