When to avoid tests for prostate cancer

As cancer cases increase, many Kenyans are keen on adopting healthy lifestyles and embracing regular check-ups to reduce their risk of getting the disease.

It is for this reason that Peter Mwangangi (not his real name) – aged 40 - decided to undergo a prostate specific antigen (PSA) test, which is used to screen for prostate cancer.

People with low amounts of PSA proteins in their blood are normally considered ‘safe’ while those with elevated PSA levels (exceeding four nanograms per millilitre) are usually suspected to suffer from the disease.

This is because cancerous cells in the prostate gland are known to enhance the production of PSA in affected people.

“This test is something that I decided to do for fun because I am a health freak. I didn’t have any symptoms. But when the results indicated that I had high PSA levels, I freaked out! Cancer felt so real. It was no longer that far away disease that only affects others.”

However, Mwangangi was later declared cancer free after doctors conducted further tests (digital rectal exam and biopsy), which confirmed that he did not have the disease.

“I was happy of course! But the waiting period was such a tough time for me and my family. We were all worried,” he said.

He is among the increasing number of men falling prey to false-positive results associated with PSA tests. This occurs when a man’s PSA level is elevated, but no cancer is actually present.

Such cases are common since aside from cancer cells, there are other factors that may increase men’s PSA levels. They include urinary tract infection, inflamed, infected or swollen prostate glands.

And now health experts are increasingly discouraging the tests among healthy men that show no signs of the disease as was the case with Mwangangi.

Indeed, results of a new large-scale study published in the Journal of the American Medical Association (JAMA) shows that inviting men with no symptoms for a one-off PSA test does not save lives.

Aside from the false-positive results, researchers found that sometimes the tests can indicate that someone has low PSA levels when they may indeed be suffering from aggressive or lethal prostate cancers. This is known as a false-negative result.

In addition, the scientists from the Universities of Bristol and Oxford also found that the tests may lead to the discovery of small tumours, which though cancerous, are so slow growing and may thus never reach a level where they can affect or harm men.

Making a decision to treat such tumours is known as ‘over-treatment’ and it is increasingly being discouraged by health experts.

This is due to the fact that it exposes men unnecessarily to harmful side-effects of radiation and surgery used for treating early prostate cancer including urinary incontinence (inability to control urine flow), problems with bowel function, impotence and infection.

For such cases, watchful waiting or active surveillance is recommended. This involves monitoring patients without delivering treatment - especially if they have a low risk of developing the disease or limited life expectancy.

Based on this continuous observation, doctors can then identify when treatment is required. That may happen if they notice that the tumour has begun growing at an alarming speed.

But this approach is also problematic as affected individuals end up living with fear and anxiety throughout the ‘wait-and-see’ period.

Due to the inconsistent or misleading results emanating from single PSA tests, the researchers in the JAMA study noted that there is need to find better ways of diagnosing aggressive prostate cancers that need to be treated early.

“The PSA test is a blunt tool missing the subtleties of the disease and causing men harm. This trial illustrates that we need to develop more accurate tools if we want to save men’s lives,” stated Dr Richard Roope of Cancer Research UK.

The study, which included more than 400,000 men aged between 50 and 69 in the United Kingdom (UK), is the largest trial ever to investigate prostate cancer screening. It compared 189,386 men who were invited to have a one-off PSA test with 219,439 men who were not invited for screening.

After an average of 10 years follow-up, results showed that both groups had the same percentage of men dying from prostate cancer (meaning that early screening was not associated with any benefits with regards to death prevention).

“Our large study has shed light on a highly debated issue. We found that offering a single PSA test to men with no symptoms of prostate cancer does not save lives after an average follow-up of 10 years,” said Professor Richard Martin, lead author of the study.

He added: “The results highlight the multitude of issues the PSA test raises - causing unnecessary anxiety and treatment by diagnosing prostate cancer in men who would never have been affected by it and failing to detect dangerous prostate cancers.

Symptoms of the disease include: erectile dysfunction (difficulties in getting an erection), a burning sensation or pain during urination, frequent urges to urinate at night, blood in urine and loss of bladder control or decreased flow of urine.

Due to the growing multitude of studies discouraging PSA tests, the Ministry of Health has no national screening programme for prostate cancer.

However, men above 50 who are concerned about their risk of developing the disease are urged to do so. The age reduces to 45 for those with a family history of prostate cancer.