Prostate Health Index

The Prostate Health Index (phi for short in English) is a clinically recognized prostate cancer risk prediction marker that is more than 30% more accurate than traditional prostate specific antigen (PSA). Its core function is to help patients with PSA in the gray zone avoid unnecessary prostate biopsy.

I met a 47-year-old private company owner in the clinic last week. The total PSA during the physical examination was 5.8ng/ml, which was just stuck in the "gray range" of 4-10ng/ml. I took the report and searched online all night, and my eyes were swollen. The first thing I said when I walked in was "Doctor, do I have cancer? Do I need a puncture immediately?" I first asked him to take a phi test, and the result came out to be 19.7, which is far lower than the commonly used cutoff value of 27. The risk of prostate cancer was calculated for him to be less than 3%. A six-month follow-up was enough, and no puncture was needed. He breathed a sigh of relief on the spot and almost bowed to me.

Many people may have heard of this indicator for the first time. In fact, it is not a fancy new technology. Its essence is to combine the total PSA and free PSA that we often check, plus a more sensitive PSA precursor subtype [-2] proPSA. The three values ​​are put into a fixed formula to calculate the comprehensive score - equivalent to installing a filter on a single PSA result, which can screen out elevated PSA caused by benign problems such as prostatitis and prostatic hyperplasia, greatly reducing the possibility of misjudgment.

Of course, the application of phi in the industry is not completely unified. For example, tertiary urology departments in Beijing, Shanghai and Guangzhou have basically regarded phi testing as a routine operation for patients in the PSA gray area. Some centers even recommend that high-risk groups over 45 years old with a family history of prostate cancer directly check phi and PSA together for the initial screening. In the early years, our center calculated that for patients with phi higher than 35, the puncture positive rate can reach 62%, which is twice as accurate as the accuracy of PSA alone. However, many grassroots hospitals have not yet popularized this project. Many doctors are still used to deciding whether to perform a puncture based on PSA value + digital examination alone. Many patients who do not need to have a puncture suffer every year - after all, prostate puncture requires inserting a needle from the perineum or rectum, and at least a dozen needles are inserted. There are risks of postoperative bleeding and infection, pain is secondary, and the psychological pressure is the most painful.

But don’t regard phi as the gold standard. I met a 39-year-old patient last year. His father was diagnosed with prostate cancer at the age of 60. He is a high-risk group. He has regular physical examinations every year. Last year, his PSA was 4.1ng/ml and his phi was only 18.2. The risk is said to be extremely low. However, he did a digital rectal examination and found a hard nodule. An MRI found an abnormal signal in the periphery. After the puncture, it was indeed low-risk prostate cancer. It was discovered early and it was removed with a minimally invasive procedure. Now there is no impact. Therefore, in clinical practice, we will not draw conclusions based on phi alone. We should make a comprehensive judgment based on the results of digital examination and prostate MRI to avoid missed diagnosis.

To be honest, when many men reach middle age, they are scared to death when they see a high PSA during a physical examination. It is completely unnecessary. If your PSA is between 4 and 10, and you have no acute symptoms such as difficulty urinating or painful urination, and no clear family history of prostate cancer, don’t rush to make an appointment for a puncture. First, ask the local hospital if the phi can be checked. If the phi is lower than 27, you can basically take it easy and just follow up every year. If the phi is higher than 35, you need to be vigilant. It is best to further do a multiparametric prostate MRI before considering whether to have a puncture.

By the way, there are no special requirements for checking phi. It doesn't matter if you have an empty stomach or not. Just draw a tube of venous blood and it's done. The price is about 200 yuan, and it is covered by medical insurance in most areas. Compared with the cost and suffering of puncture, the price-performance ratio is really much higher. After all, the core purpose of our cancer screening is not to miss the real problem and not to suffer from the disease.