When it comes to PSA testing there are 4 important things to know.
PSA testing may lead to fewer men dying from prostate cancer or developing advanced prostate cancer.
The aim of PSA testing is to reduce the number of men who die of prostate cancer. PSA testing also reduces the chances that a man will be diagnosed with advanced prostate cancer. Since reduction in deaths from prostate cancer is only seen 7 or more years after PSA testing, testing is not recommended for men who, due to their age or health, are unlikely to live another 7 years.
Out of 1000 men who have PSA testing every 2 years from 50 to 69 years of age…
still die from prostate cancer.
avoids dying from prostate cancer because of testing.
avoids being diagnosed with advanced prostate cancer because of testing.
is still diagnosed with advanced prostate cancer.1
PSA testing leads to finding some prostate cancers that are not harmful (over-diagnosis).
Cancers found by PSA testing are treated to try and prevent problems later. But some cancers found by PSA testing would never cause problems anyway. Cancers like this may grow very slowly or just stay the same. Without PSA testing they would never be noticed or cause any trouble. Finding these cancers through PSA testing is called over-diagnosis.
Doctors cannot be sure which cancers will be harmless, even after further checks and examination. Therefore, either active surveillance or treatment is recommended. So, across all the men who have PSA testing, some end up having active surveillance or treatment they do not need.
Imagine a man called Tom who develops a small, slow-growing prostate cancer in his 50s or 60s. The picture below shows two possible scenarios that could happen to Tom.
Tom’s life span is the same whether or not he has PSA testing. So, if he has PSA testing, he experiences over-diagnosis.
Out of 1000 men who have PSA testing every 2 years from 50 to 69 years of age, 72 men are diagnosed with prostate cancer.
25 of these men
experience over-diagnosis: that is they are diagnosed and treated for a cancer that would never have caused him any trouble.
47 of these men
are diagnosed with prostate cancer that is not over-diagnosed.1
Prostate cancer treatment can cause unwanted side effects.
How is early prostate cancer treated?
Treatments for early prostate cancer include surgery (radical prostatectomy), radiation therapy and hormone therapy. Men diagnosed with low-risk prostate cancer may be offered active surveillance, which involves close follow-up with repeat PSA tests, digital rectal examination and biopsy with the aim of avoiding unnecessary treatment. Treatment will be offered, though, if there are signs that the cancer is advancing.
How is advanced prostate cancer treated?
Hormone therapy, chemotherapy and radiation therapy are the treatments most often used. Hormone therapy and chemotherapy can slow the advance of the cancer. In addition to side effects described above, long-term hormone therapy can weaken bones and cause obesity. Radiation Therapy is mostly used to control symptoms such as pain from cancer deposits in bones or pressing on nerves.
What are the unwanted side effects of treatment for early prostate cancer?
Common unwanted effects of treatment for prostate cancer include difficulty in holding urine (urinary incontinence), difficulty getting or maintaining an erection (impotence), and bowel problems, such as diarrhoea, difficulty in controlling bowel movements, and rectal bleeding. Hormone therapy, which is usually given for a period with or after radiation therapy, commonly causes loss of interest in sex, hot flashes, tiredness, loss of physical strength, mood swings and growth of breast tissue.
PSA testing leads to some false positive results and extra testing.
Like any other cancer test, a PSA test is not perfect. Sometimes the result looks abnormal and the man is recalled for extra tests, but it turns out that there is no cancer so it was a false alarm. These false alarms from PSA testing are called false positive results.
Men often feel anxious while they are having the extra tests and waiting for their results, and then feel relieved when they are told there is no cancer after all. However, some men find that they keep worrying about prostate cancer for a while afterwards.
How is over-diagnosis different from false positives?
False positives occur in men who do not have prostate cancer. These men have an abnormal PSA test result, but then extra tests show they do not have cancer. By contrast, in cases of over-diagnosis the men do have prostate cancer confirmed by the extra tests, so they get a cancer diagnosis and treatment.
Out of 1000 men who have PSA testing every 2 years from 50 to 69 years of age over 20 years…
will experience one or more false positive results: that is they will have an abnormal PSA test and a following biopsy of the prostate that does not find any cancer.1