A long-term follow up of prostate cancer patients shows that the option of monitoring slow-growing prostate cancer may not be as safe as thought, due to a quarter of men dropping out of the monitoring programme.
Prostate cancer is the most common cancer in men, with a European incidence rate of 214 cases per 1000 men, outnumbering lung and colorectal cancer. Research shows that with advancing age, most men are likely to have a cancer of the prostate, although for many the cancer will be so slow growing that it does not create a real problem. Recently there has been significant visibility given to the risk of prostate-cancer "overdiagnosis" - treatment when it is not justified by a serious health threat.
Given that treatment for prostate cancer involves either radiotherapy or major surgery, and that this can have significant side-effects, such as incontinence and impotence, there has been an increasing tendency to keep low-risk men under "active surveillance"; in other words not to treat the cancer immediately by surgery or radiotherapy, but to monitor the cancer regularly to see if it worsens. However, there have been very few studies showing how this surveillance works in real life.
Now a group of researchers from Baden in Switzerland have presented a long-term study to the European Association of Urology Congress in Stockholm which raises concerns regarding the safety of active surveillance. The study was based in a normal-sized hospital rather than in an academic medical centre, so is probably representative of how prostate cancer is followed up in the real world. This study followed 157 patients over a 13 period years active surveillance. After 13 years it was found that around a ¼ (28%) of all patients needed definitive treatment. Almost all of these men were cured from cancer. However, it was also found that about another ¼ (27%) of all patients did not show up to the recommended appointments - which actually is the key element of active surveillance.
These men did not reply to follow-up letters requesting ongoing check-up, thus dropping out of the active surveillance system.
As lead researcher Dr Lukas Hefermehl said
"The limitation of this study is that this is not a huge sample, but nevertheless it is one of the best "real-world" samples we have with long-term data. I strongly believe that active surveillance is a good option for men who follow the recommended controls. But from our results it looks like there must be a significant number of men lost to follow up who will eventually develop a progressive disease; many of these men may even eventually die of prostate cancer. As Urologists we still remain responsible for these patients".
The group also found that just 3 months after the initial diagnosis, 30 men (19%) refused a mandatory confirmation biopsy which could have ruled out a wrong interpretation of the first biopsy.
Dr Hefermehl continued:
We don't know exactly what the reasons are. It may be that once the patient was told that this cancer is probably "not immediately threatening" , he might downplay the importance of another test. On the other hand some men might have real concerns about the risk of there being a more severe cancer. Or it may be to do with the risk of incontinence or impotence after treatment, the idea of having cancer, a sense that nothing will really happen to them or it may be due to another reason which we just don't know about".
But the fact is that overall these findings leave us with a practical and ethical dilemma; we often recommend that men go onto an active surveillance programme, but these results indicate that more than a quarter of men will disappear from the system. We strongly believe that this "patient factor" must be taken into account for future active surveillance protocols"
Commenting, Professor Manfred Wirth (Technical University of Dresden), Treasurer and Executive Member, Communication, of the European Association of Urology said:
"This is very interesting and potentially controversial work, which is based on clinical practice in the real world. It shows that we may need a clearer understanding of the psychological factors which might get in the way of effective follow up in these points."