Prostate-specific antigen (PSA) is a protein produced by both malignant and normal prostate cells. The PSA test measures the levels of PSA in the blood. The results of the test are usually reported in units of ng/mL (nanograms per milliliter).
In normal males, the PSA level typically ranges from 2.5 to 4.0 ng/mL.
The main cause of an increase in PSA levels is prostate cancer.
However, there are other prostate or urinary tract health issues that can also raise PSA levels, including:
Additionally, factors such as urinary catheterization, aging, parathyroid hormone, prostate manipulation, and ejaculation can also elevate PSA levels.
On the other hand, the upper limit of the normal value, 4.0 ng/mL, may not apply to men of all age groups.
As for the normal PSA values for different age groups, the following table can be used as a reference:
|Age||Range Adjusted Normal Level (ng/mL)|
|40 – 49 years old||0 – 2.5|
|50 – 59 years old||0 – 3.5|
|60 – 69 years old||0 – 4.5|
|70 years old and above||0 – 6.5|
|PSA Level (ng/mL)||Risk of Cancer|
|0 – 2.5||Very low risk of prostate cancer|
|2.5 – 4|
|4 – 10||25% chance of having cancer, further tests may be conducted for diagnosis|
|10||This level is considered high risk with a 50% chance of having cancer|
However, according to statistics from the NHS, about 3 out of 4 men with an elevated PSA level do not have cancer. Additionally, for every 7 men with a normal PSA level, one may still have prostate cancer. This indicates that the PSA test is not the best diagnostic method for prostate cancer.
The advantages of PSA testing include:
However, there are also disadvantages to consider:
Therefore, some medical articles suggest that unless there is a high familial risk, PSA testing is most suitable for men aged 55-69 years (as determined by a doctor).
If the PSA level is abnormal, it does not necessarily mean that you have prostate cancer. The doctor may recommend the following methods to determine the cause:
In Hong Kong, many private hospitals and clinics offer PSA testing services, with costs ranging from HK$2,000 to HK$8,500.
Some studies suggest that consuming more tomatoes, choosing healthy protein foods, getting sufficient vitamin D, drinking green tea, and exercising regularly can naturally lower PSA levels.
The Hong Kong Urological Association recommends considering PSA screening every 2 years if the PSA index is normal (<4ng/mL).