Screening for Prostate Cancer. What do you need to know?

Article written by Dr Jerome.

What is Prostate cancer?

Prostate cancer is the third most common cancer among men. Prostate cancer is rare in men under the age of 50 years. The risk is greater in those with a family history. Prostate cancers range from slow growing to aggressive cancers. Slow growing cancers are common and may not cause any symptoms or shorten life. Most men with prostate cancer will not die from it.

Who should be screened?

Men between 50 and 75 years of age with estimated life expectancy of more than 10 years, may be offered screening for prostate cancer. High-risk men, such as African-American men and men with strong family history of prostate cancer ( 1 or more first-degree relatives diagnosed before age 65 years), may be offered screening at an earlier age. Screening should not be offered to men less than 50 years. It should also not be done on men with life expectancy less than 10-15 years because testing and treatment is unlikely to be beneficial.

What is prostate surface antigen (PSA) and how it can be used as a screening test ?

PSA is a substance made by the prostate gland. The PSA test is a blood test measuring the level of PSA in the blood. A raised PSA can be an early indication of prostate cancer. Hence, it is called a tumour marker. About 2/3 of men with raised PSA level will not have prostate cancer. The higher the PSA level, the more likely it is to be cancer. There is no conclusive evidence that PSA screening in asymptomatic men will improve the mortality of men with prostate cancer.

Tumor markers are useful once a patient has a diagnosis of cancer and is used to aid in prognosis, management and monitoring of recurrence or response to therapy.

What are the pitfalls of PSA test?

PSA test is not a perfect test. It would be easy to assume that if the test is positive, one is more likely to have cancer. But there are other conditions which can cause a rise in PSA, for example, prostate enlargement, prostatitis, urinary infection. Hence, this may cause unnecessary mental stress and anxiety over the possibility of having cancer.

Similarly, when the PSA test is negative, prostate cancer can still be present. This can be seen in patients taking medications for enlarged prostate or hair loss.

How often do we do PSA screening?

In general, PSA screening is done on an annual basis. However, this screening may be performed once every 2 years in low risk men with baseline PSA less than 1.0ng/mL

When you receive the PSA results, what are the follow up actions?

If the PSA is elevated, a prostate biopsy is required to determine if cancer is present. Prostate biopsy is generally safe. However, there is a small risk of complications such as bleeding and urinary tract infections. Approximately 2/3 of men who have a biopsy will not have prostate cancer.

If the PSA is normal or low, reassurance can be given but bearing in mind that patients taking medications for enlarged prostate or hair loss can have artificially low levels of PSA. PSA screening can be continued on an annual basis.

References:

Cancer Screening. MOH Clinical Practice Guidelines 2010.


Disclaimer: This article provides general advice for the public. Please seek official advice from your primary physician.