A trial comparing treatment approaches for prostate cancer (ProtecT)

The researchers followed the men who took part in the trial over an average of 10 years.

They found the numbers of men who died from prostate cancer was low in all 3 treatment groups

Men who had surgery and radiotherapy had lower rates of their cancer growing or spreading elsewhere in the body.

The team also found differences in the side effects people had from treatment. Men who had surgery were more likely to have problems with their sexual function and leaking urine (urinary incontinence). Men who had radiotherapy also had problems with sexual function and their bowels.

Men aged 50 to 69 years took part in the trial between 1999 and 2009. The groups were compared up to the end of 2015.

The research team invited 228,966 men to have an appointment with a specialist nurse to talk about having a PSA blood test.

More than 4 out of 10 men (44%) agreed to the appointment. And most of these men (82%) agreed to have a PSA test. Of these 82,429 men:

• nearly 9 out of 10 (89%) had a PSA test result of less than 3ng/ml
• 3 out of 1000 men (less than 1%) had a PSA result of over 20ng/ml
• just over 1 in 10 men (11%) had a PSA test result of between 3ng/ml and 20ng/ml, and most of these men (87%) went on to have a sample of tissue taken (a prostate biopsy)

Out of the 7,414 men who had a biopsy

• 2,896 were diagnosed with prostate cancer
• 2,417 of them had localised prostate cancer

The researchers also included 247 men who had been diagnosed with localised prostate cancer as part of an earlier pilot study, so there were 2,664 men in total.

Of these, more than 6 out of 10 (62%) agreed to have their treatment chosen at random. This means they did not choose which treatment group they were in.

• 545 radiotherapy
• 553 surgery to remove their prostate gland (prostatectomy)
• 545 active monitoring

Active monitoring means that you are carefully monitored by your doctor or nurse. You don’t have treatment straight away. You have the option to start treatment if:

• there is any sign that your cancer is beginning to change or grow
• your doctor advises you to
• you wish to

By the end of 2015, 291 men in the active monitoring group went on to have radiotherapy or surgery.

Some men in the radiotherapy and surgery groups also went on to have other treatments, as part of their routine care.

The research team followed the men up for an average of 10 years after treatment. They looked at how many:

• died from prostate cancer
• had cancer that had grown or spread
• died from causes other than cancer
• had side effects from the treatment

The researchers did not have data for 14 men (they were lost to follow up). This accounts for just 1%. But they know that they had accurate data for all the men who died.

They found the numbers of men who died from prostate cancer were:

• 8 men in the active monitoring group
• 5 men in the surgery group
• 4 men in the radiotherapy group

And the numbers of men who died from causes not related to their prostate cancer:

• 51 men in the active monitoring group
• 50 men in the surgery group
• 51 men in the radiotherapy group

The researchers say that the differences in these numbers are not statistically significant. This means they could have happened by chance.

But there were differences in the number of men whose cancer had grown or spread.

The number of men whose cancer had grown (clinical progression) was:

• 112 men in the active monitoring group
• 46 men in the surgery group
• 46 men in the radiotherapy group

And the number of men whose cancer had spread (metastasised):

• 33 men in the active monitoring group
• 13 men in the surgery group
• 16 men in the radiotherapy group

Side effects and Quality of Life
The researchers asked the men to complete questionnaires regularly about the side effects they had. These are called patient reported outcomes.  

It is important to note that as well as treatment for their cancer, many men in the study also had treatment to help with side effects of their cancer. And these treatments might have also contributed to the side effects men had.

1643 men completed questionnaires:

• before their diagnosis
• 6 and 12 months after they were randomised to a treatment group
• then every year

55 men stopped completing questionnaire and some men did not complete the questionnaires every time.

The questionnaires looked at the effect on quality of life in 4 main areas (domains). These were:

• urinary function
• sexual function
• bowel function
• general physical and mental health

Urinary function
Men who had a prostatectomy had the worse urinary incontinence. 

Although this did improve in time, throughout follow up this group of men always reported urine leakage being worse than the men in the other groups. And this had a negative effect on their quality of life, particularly in the first 2 years after treatment.

One way urinary incontinence is measured is by use of pads. 6 years after treatment, the numbers of men needing to use pads were:

• 79 out of 455 in the surgery group
• 38 out of 453 in the active monitoring group
• 16 out of 452 in the radiotherapy group

Sexual function
Before treatment almost 7 out of 10 men reported that they had an erection that was firm enough for intercourse. 6 months after treatment the numbers were:

• 173 out of 375 in the active monitoring group
• 75 out of 338 in the radiotherapy group
• 43 out of 359 in the surgery group

There was greater improvement in the radiotherapy group but sexual function remained poor in the surgery group. In the active monitoring group the rate gradually declined every year. At year 6 the number of men who had an erection firm enough for intercourse was:

• 134 out of 452 in the active monitoring group
• 125 out of 456 in the radiotherapy group
• 76 out of 456 in the surgery group

Bowel function
Men in the radiotherapy group reported worse bowel problems such as loose poo and not being able to control their bowels (faecal incontinence). This improved after a year or two, except for small numbers who experienced blood in poo increasing a little over time. Men in the surgery and active monitoring groups reported little change in their bowel function.

At year 6 the numbers of men who had loose poo about half the time or more frequently were:

• 61 out of 466 in the active monitoring group
• 72 out of 466 in the radiotherapy group
• 57 out of 468 in the surgery group

Health related
There were no significant differences in any of the treatment groups in relation to general physical and mental health. There were no differences either in anxiety or depression between the groups. 

Overall conclusions
The researchers concluded that there were similar high rates of survival in all 3 treatment groups. But there were differences in the rates of growth and spread of the cancer and the side effects of treatment. They say each of the treatments has a role in treating localised prostate cancer. And that longer follow up is needed to see whether things change over the next five to ten years.

The researchers think the results of this study provide patients and doctors with detailed information about the effects and impact of each treatment. This should help men to make an informed decision about which treatment to have.

We have based this summary on information from the team who ran the trial. The information they sent us has been reviewed by independent specialists (peer reviewed ) and published in a medical journal. The figures we quote above were provided by the trial team. We have not analysed the data ourselves.