Does a high PSA blood test mean you have prostate cancer?

Men typically associate PSA (prostate-specific antigen) with prostate cancer and a high PSA with a greater risk of developing the disease.

However, does a high PSA mean prostate cancer every time? Fortunately, the answer is no, but there is more to this answer.

How high is too high?

This is an excellent question, yet experts don’t agree on the answer. If one man has a PSA of 5.0 ng/mL and another has a value of 7.5 ng/mL, is the second guy at greater risk of prostate cancer and dying of the disease? Scientists have been exploring this question, and here’s what one Danish study had to say.

The 28-year follow-up study, which examined blood samples from 4,383 healthy men, found that the 10-year absolute risk for developing prostate cancer was 11 to 22 percent for men whose PSA level was 4.01 to 10.0 ng/mL and 37 to 79 percent for those with a PSA level greater than 10.0 ng/mL.

A level of 10.0 ng/mL is often used as the dividing line between lower and higher risk of developing the disease. Of course, this figure should be viewed as a guide only, as every man and his situation is unique.

Does a high PSA mean I have prostate cancer?

It’s possible, but there are many other factors that can cause a man’s PSA level to be elevated, and none of them have anything to do with cancer. For example, the presence of an enlarged prostate or prostatitis can boost PSA levels. Men who have ejaculated within 24 to 48 hours of having their PSA checked may have a higher PSA than normal.

Other reasons a PSA level may be elevated include presence of a urinary tract infection, recent use of a urinary catheter, and having undergone a digital rectal exam within the past few days. If you get a high reading on your PSA test, it is recommended you have a second test four to six weeks later to verify the original results, as a man’s PSA levels can fluctuate.

Read more: 15 Things That Can Increase PSA Levels

Is there a PSA level at which prostate cancer risk is zero?

According to the Cleveland Clinic and other experts, “There is no PSA level below which the risk of cancer is zero.” In the Danish study, for example, the researchers found that for men with a PSA of 1.0 ng/mL or less, there was still a minute risk: 0.6 to 1.5 percent.

What are other risk factors for prostate cancer?

Two men who have the same PSA levels can have very different chances of developing prostate cancer, depending on other risk factors. For example, having a history of prostate cancer in the immediate family (father, grandfather, sons), being African-American or Caribbean of African ancestry, age older than 65, genetics (some gene changes have been associated with an increased risk), a diet high in animal products, and living in North America, Australia, northwestern Europe, and the Caribbean.

Read more: Understanding the PSA Test for Prostate Cancer

Sources:

1. Cleveland Clinic. Elevated PSA (prostate-specific antigen) level

2. Orsted DD et al. Prostate-specific antigen and long-term prediction of prostate cancer incidence and mortality in the general population. European Urology 2012 May; 61(5): 865-74