Madam, - Your Health Supplement of October 9th includes a very short synopsis of an article published in the Archives of Internal Medicine which reported on the "Short- and Long-term Mortality with Localised Prostate Cancer".
In the interest of patients currently facing a difficult decision on what is the correct treatment for them, I think it is important to draw attention to the significant limitations of this study.
In the first instance, the number of patients included in the analysis was relatively small and therefore definitive conclusions are difficult to establish (prostatectomy patients numbered only 158, radiotherapy 205 and watchful waiting 378). The authors collected data from the Geneva Cancer Registry and consequently the study was de facto a retrospective population-based study.
The problem with this type of information collection is that it gives no clue as to why patients were treated one way instead of another. The treatments were not randomly assigned and therefore confounding factors no doubt apply.
Outside the confines of a randomised clinical trial, older, sicker patients will be directed towards radiotherapy or watchful waiting, while younger fitter patients will be selected for surgery. This was no doubt the case in the Geneva study.
On reading the entire article, several other very important points are revealed. In over one third of patients the lymph node status was unknown and therefore it is impossible retrospectively to ascertain if those patients had localised disease or not. In over one quarter of patients the PSA (prostate specific antigen, a blood test which is useful in pre- and post-treatment assessment) was unknown and in a further 16 per cent the Gleason score (a pathological assessment of biopsy material which gives a good indication of tumour aggressiveness and likely behaviour) was unknown. These two parameters are very important when deciding on appropriate treatment selection. In addition, there is absolutely no reference to quality of life parameters, which are a very significant consideration for any patient embarking on prostate cancer treatment.
Finally, the median follow-up for the entire cohort was 6.8 years, which in terms of prostate cancer would not be considered long, and the number of patients remaining at risk (i.e. still alive) at 10 years was just 44, 68 and 78 for the surgical, radiotherapy and watchful waiting groups respectively. These are tiny numbers on which to base any conclusions.
I recognise that it is important to disseminate information to patients so that they are in the best possible position to make an informed decision about their treatment. Prostatectomy is an excellent and appropriate choice for some prostate cancer patients. However, it is also important to ensure that the justification for prostatectomy is not based on poorly conducted research. Other forms of treatment such as modern-day radiation therapy would no doubt be equally valid for some patients.
In my opinion, patients would be better served by having honest and frank discussions with the general practitioners, urologists and radiation oncologists involved in their care and The Irish Times's Health Supplement should refrain from highlighting articles that could prove to be extremely misleading for patients as they struggle to decide on the best course of action. - Yours, etc,
Dr MICHAEL MAHER, Healthfield Road, Terenure, Dublin 6