It is a little out of the normal scope of this blog, but a recent prostate cancer study from Canada has received a lot of buzz and needs some commentary and analysis. The study concluded that for men who are diagnosed with local prostate cancer (still confined in the gland) live longer if they have surgery as opposed to radiation. Despite this conclusion, this study should not change anyone’s clinical course or decision making!
This study was a meta-analysis of a lot of data from a lot of studies and on the face of its conclusions it should change clinical practice! But wait, not to fast because there are some mitigating issues that need to be examined.
In simple terms, the study measured the risk of mortality (death) for prostate cancer in men who had surgery as opposed to radiation (with brachytherapy or external beam radiotherapy) as their primary treatment. The study was very large (over 118,000 men), using data generated from 19 previous studies that were designed to measure the risk of death for men with localized prostate cancer (prostate cancer still in the gland).
The study concluded that the risk of death was greater for those who had radiotherapy compared to those who had surgery. The study analyzed both mortality from any cause, and mortality specifically from prostate cancer and it found that the mortality was higher, in both cases, in the radiotherapy group than the surgery group.
The study authors did point out that their data is not sufficient to change clinical guidelines, and we agree with this conclusion. The authors correctly describe the potential for bias in their results that resulted from the study design itself. They cited, as an example of the potential bias, that the men in the studies received their treatments, both radiotherapy and surgery, at different facilities with different doctors which by itself could explain the mortality differences. It is possible that the difference in mortality was unrelated to the actual treatment.
Usually, be think that long term data is better, but in this particular analysis it could also have contributed to less reliable outcomes! The studies, used in the meta-analysis, started as early as the 1980s and both radiotherapy and surgical techniques have had many changes over this period. Current radiotherapy and surgical techniques likely have a different risk of mortality than those used for many of the men in this study.
A recent Australian study) concluded, “modern EBRT is at least as effective as modern Australian surgical and brachytherapy techniques. All patients considering treatment for localized prostate cancer should be referred to a radiation oncologist to discuss EBRT as an equivalent option.”
However, this study was much smaller and only followed the subject men over a five-year period, in prostate cancer terms not really long enough to form valid conclusions about long term mortality.
Given the different conclusions of these two studies it only becomes clearer that we are in need for a good, randomized study evaluating mortality rates for men with localized prostate cancer, both short and long terms, using current radiology and surgical techniques.