This article appeared in the Fairfax press today. It contains some background about a new prostate cancer treatment. It also gives some insight into which treatments are and are not brought to market by the handful of pharma companies that control the development of new medicines.
I had heard about lutetium through the Prostate Cancer Foundation of Australia (linked in the Resources section of this blog). The following excerpt from a paper given by Professor de Bono at the European Society of Medical Oncologists’ conference in September 2017, is lifted from a message to a PCFA discussion list. The paper concluded
this phase II trial demonstrates that 177Lu-PSMA treatment for patients with MCRPC who have failed standard therapy provides encouraging response rates with acceptable toxicity, in addition to improved QoL and pain reduction. Based on this trial, we eagerly await the results of larger studies with long-term follow-up.
- MCRPC = Metastatic Castration Resistant Prostate Cancer
- QoL = quality of life
Hormone therapy, also known as androgen deprivation therapy, is basically chemical castration. This is one of the “standard therapies” that have failed those in the lutetium trial. In other words, lutetium is, at present, a last resort. (Not that this makes it any less desirable for those participating in the trial!)
The discussion attached to The Age article linked above had an interesting further observation about PSA testing. (One needs to log in to the web site to read this discussion.) One of the posts claimed that the PSA test was a less accurate predictor of prostate cancer than a biopsy. A response observed correctly that, for men in whom cancer had not been diagnosed, a high PSA score is not necessarily an indicator of prostate cancer. In men in whom prostate cancer has been confirmed, however, PSA tests are routinely used to assess how effective a treatment has been. So in terms of how “good” the PSA test is, it depends if one is talking about it used as
- an initial screening test, or
- a test in men with confirmed prostate cancer.
PSA should not solely be relied on as a screening test. It is routinely used in the latter context.
I have had about five PSA tests in the course of my treatment so far, and a biopsy as well. The PSA sends up the red flag for the possible presence of cancer, the biopsy reveals the location and type of cancer. You wouldn’t do a biopsy without an elevated PSA score. (In my case, this was confirmed by a second PSA test). The PSA can be done in a few minutes at a pathology centre; my biopsy was performed under a general anaesthetic. One can’t replace the other. They do different things.