Prostate health index normal range

The current normal clinical reference range of the prostate health index (phi) is <27ng/ml. However, this value is not an absolute one-size-fits-all standard. The reagent calibration standards of different testing institutions and the baseline characteristics of the tested population are different, so the reference threshold will fluctuate up and down.

Last week, I met a 42-year-old programmer named Lao Chen in the outpatient clinic. His physical examination showed that his total PSA was 7.2ng/ml. He was stuck in what is often called the “gray zone.” I first prescribed a phi test for him, and the result came out to be 22ng/ml. Combined with the fact that no induration was found during the digital rectal examination, I asked him to go back for a reexamination in 3 months. He would not have to suffer a puncture for the time being. I still remember the sigh he gave when he took the report.

Many people are unfamiliar with this indicator. In fact, phi is a composite calculated value. It needs to be combined with the three results of total PSA, free PSA, and the more sensitive [-2] proPSA and substituted into the formula for conversion. It was originally born to solve the problem of difficulty in judging benign and malignant in the gray area of ​​total PSA. It is more than one level higher than the accuracy of looking at PSA alone.

At present, there is no completely unified conclusion about the threshold of phi in the industry. Most European and American urology guidelines set the threshold for high-risk groups even more stringently, setting it at <25ng/ml, especially for people under 50 years old, with a family history of prostate cancer, and carrying BRCA gene mutations. As long as it exceeds 25, further imaging screening will be recommended.； Many primary hospitals in China will appropriately relax the threshold to <30ng/ml for elderly people over 60 years old who have been diagnosed with obvious prostate hyperplasia. After all, the hyperplasia of the prostate itself will slightly increase PSA-related indicators. If it is too stuck, it will easily lead to many elderly people who have no problems to undergo unnecessary invasive examinations, which will increase the risk of infection.

I have been in clinical practice for almost 10 years, and I have never used the phi value as the only criterion. Last month, I met a 58-year-old man whose phi was found to be 26ng/ml, which is just below the universal normal line. However, his brother and father both had prostate cancer and were in a clear high-risk group. I still insisted on letting him do a multi-parameter prostate MRI. Finally, I found a small nodule less than 1cm in the peripheral zone of the prostate. After puncture, it was very early-stage prostate cancer. After radical surgery, it basically did not affect his subsequent life. If he had only let him go with the normal value at that time, the consequences would be hard to predict.

People who have physical examinations often ask me if I should do a regular phi test every year? In fact, it is really unnecessary. It is enough for ordinary healthy men to have a total PSA for an annual physical examination. Only those whose total PSA falls in the gray area of ​​4-10ng/ml and no obvious abnormalities are found in the digital rectal examination need to have a follow-up phi test. Current data shows that using phi for screening can reduce unnecessary prostate punctures by about 30%. After all, puncture is an invasive operation that requires dozens of needles from the perineum or rectum. It is definitely good to avoid this sin.

By the way, there are some things to pay attention to before checking phi. It is best not to ride a bicycle or have sex in the first 24 hours, and do not draw blood right after a digital rectal examination or prostate massage. These actions will squeeze the prostate and may cause the indicator to rise falsely. It should be no problem to detect an abnormal value, but it will scare yourself for several days for no reason. What a loss.

Ultimately, the so-called normal range is essentially just a reference scale, not a final verdict. After getting the report, don't scare yourself just by looking at the numerical values. It is much more reliable to make a comprehensive judgment from a doctor based on your age, family history, and other test results than to blindly speculate on the standards on Baidu.