Low-risk prostate cancer: Active surveillance or treatment?

Photo of a doctor talking to a patient (PantherMedia / Monkeybusiness Images) Low-risk prostate cancer often grows very slowly, or doesn't grow at all. Because of this, a treatment approach known as "active surveillance" can be considered as an alternative to radiotherapy or surgery. In this approach, the tumor is monitored regularly and only treated with radiotherapy or surgery if it grows.

Prostate cancer is described as “low-risk” if it is only found in the prostate (localized) and it is highly likely to grow only very slowly, or not at all (low risk of progression). The medical criteria for low-risk prostate cancer are:

  • The cancer is found in only one of the two sides (lobes) of the prostate.
  • The cancer takes up less than half of the affected prostate lobe.
  • The cancer cells haven’t mutated (changed) much and aren’t very aggressive.
  • The cancer hasn’t spread to any lymph nodes or led to the growth of tumors (metastases) in other parts of the body.

Even if the diagnosis can be worrying: Low-risk prostate cancer grows only very slowly, or sometimes doesn't grow at all. So the chances of recovery are very good. Over a time period of 10 years, only 1 out of 100 men who have low-risk prostate cancer will die of this disease. In other words: 99 out of 100 men will not die of prostate cancer in the 10 years after it is diagnosed.

There are various ways to deal with low-risk prostate cancer. All of the options have their pros and cons. So it's a good idea to get enough information and discuss the options with your doctors before making a decision.

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What are the treatment options for low-risk prostate cancer?

Men with low-risk prostate cancer have four treatment options: active surveillance, external radiotherapy, internal radiotherapy (brachytherapy) and surgery to remove the prostate.

  • Active surveillance involves monitoring the prostate cancer, and only treating it if there are signs that it is progressing. This approach is based on the fact that low-risk prostate cancer often grows very slowly or doesn't grow at all, so treatment often isn’t needed.
  • In external radiotherapy, the cancer is exposed to radiation from outside the body, through the skin.
  • In internal radiotherapy (brachytherapy), the cancer is exposed to radiation from slightly radioactive “seeds” (about the size of a grain of rice) that are implanted inside the body.
  • The aim of surgery wird (radical prostatectomy) is to remove the tumor, together with the whole prostate, seminal vesicles and outer capsule.

Radiation and the surgical removal of the prostate are also referred to as "curative" treatments because the aim is to remove all of the tumor cells. But a few cancer cells may stay in the body, or new cancer cells might develop. For this reason, men who have had radiotherapy or surgery are still advised to have regular PSA tests.

What does active surveillance involve?

Active surveillance has one big advantage: Men whose prostate cancer doesn’t grow can avoid surgery or radiotherapy, including the side effects. One disadvantage is that, if the cancer progresses, it may be discovered too late. It may have already spread to other parts of the body by then (metastasis). Knowing that you have cancer in your body can be distressing too.

Another disadvantage of active surveillance is that you have to have regular check-ups. The medical societies in Germany recommend the following:

  • A PSA test and palpation examination (feeling the prostate) every 3 to 6 months in the first two years.
  • InA total of three biopsies (tissue samples) in the first three years:
    • One biopsy after 6 months,
    • a second biopsy about 12 to 18 months after the first one, and
    • a third biopsy at the end of the three years.

After that, a biopsy should be done every three years.

What does “watchful waiting” mean?

In men who are older or have serious illnesses, the risks and distress associated with surgery or radiotherapy can outweigh the possible benefits of this treatment. Some men also say that they don’t want to have a distressing treatment. “Watchful waiting” is then an option. In this approach, the cancer isn’t treated with the aim of curing it. Instead, you may have treatment to control the cancer and manage the symptoms if you start to get symptoms.

One big difference to “active surveillance” is that you don’t need to have distressing check-ups in the “watchful waiting” approach. Watchful waiting is mainly considered in men whose prostate cancer isn’t likely to shorten their life in the next ten years. Their prostate cancer isn’t likely to grow much during that time.

How do the treatment options compare?

A study known as the ProtecT trial is the most important study on treatments for low-risk prostate cancer so far. ProtecT stands for “prostate testing for cancer and treatment.” This trial compared three treatment options: active surveillance, external radiotherapy and surgery to remove the prostate. A total of 1,643 men between the ages of 50 and 69 took part in the trial. They all agreed to be randomly assigned to one of the three treatment groups. About two thirds of them had low-risk prostate cancer. The treatment outcomes were recorded over an average of ten years, and then compared with each other at the end of the trial.

The following was found over a period of ten years:

  • no difference in mortality rate (number of deaths) between the active surveillance, radiotherapy and surgical removal groups,
  • a somewhat higher risk of metastases in the active surveillance group,
  • a much higher risk of accidental urine leakage (urinary incontinence) in men who had surgery,
  • a much higher risk of erection problems in men who had radiotherapy or surgery (after radiotherapy: particularly in the first six months).
  • a somewhat higher risk of accidental stool leakage (fecal incontinence) in men who had radiotherapy.

Based on the results of this trial and other research, we have developed a decision aid that can help men who have low-risk prostate cancer to weigh the pros and cons of the various treatment options – for example, together with their friends, family and doctors.

What remains unanswered?

The ProtecT trial has one important weakness: The participants have only been observed for ten years so far. But it would only be possible to draw any reliable conclusions about the pros and cons of the three treatment approaches after 15 or 20 years.

Surgery is the only treatment for which there is currently conclusive long-term data – gathered over a period of 23 years. This data comes from a Scandinavian study that compared the surgical removal of the prostate with the “watchful waiting” approach. But only about one third of the men in this study had low-risk prostate cancer. So it’s not possible to draw any reliable conclusions about the long-term pros and cons of the current standard treatment options for low-risk prostate cancer.

The ProtecT trial also has another limitation: The check-ups that men had in the "active surveillance" group were different from the current standard approach in Germany. In the ProtecT trial, the men had a PSA test every 3 months in the first year, and then every 6 to 12 months after that. If the PSA levels were too high or if the men developed symptoms such as problems urinating, they had further tests. In Germany, men who have abnormal PSA test results are also advised to have regular biopsies (tissue samples taken). This is meant to increase the likelihood of finding out soon enough if the cancer progresses, but it can also be more distressing.

Despite these limitations, the ProtecT trial currently provides the best basis for making a decision about the treatment of low-risk prostate cancer.

Are there other treatment options?

There hasn't been enough good research on other treatments such as "high intensity focal ultrasound" (HIFU), cryotherapy (freezing) or hyperthermia treatment (using heat). Because of this, medical societies in Germany don't recommend using them in the treatment of prostate cancer, or only recommend using them for research purposes.

Making a decision

Men who have low-risk prostate cancer can take their time to weigh the pros and cons of the various treatment options. It can be helpful to use a decision aid too.

Various factors will influence the decision, including the pros and cons of the different treatment options, and individual factors such as his age and how healthy he is overall. A young and otherwise healthy man who is still expected to live for a long time will probably weigh the pros and cons of the treatment options differently than an older man who has other medical problems and a shorter life expectancy.

It's best to discuss the pros and cons of the possible treatments with your doctors.