This small phase ll study looked at responses to the drug olarparib, and its action on a particular type of prostate tumor mutation. While the news release indicates that this is pioneering work in the field of personalized prostate cancer treatment, there is still much to be skeptical about the practice of isolating cancer-related genes with new targeted drugs. The key point not made in the news release is that the study did not demonstrate any mortality or survival benefit in the act of identifying and targeting men with mutated prostate tumors and giving them olarparib.
The news release comes across somewhat as a promotional vehicle for genetic testing and yet comparing it with the test for BRAC (breast cancer susceptibility gene) mutation would tend to give it a gloss it might not deserve. Without results with this form of “precision medicine,” hyping genetic testing around this type of metastatic prostate cancer feels a little irresponsible. The final line: “Understanding the link between prostate cancer and DNA repair mutations is incredibly important for patients and their families” seems to be putting the cart way before the horse and is likely to confuse and build unreasonable expectations among prostate cancer sufferers.
Many men still die from prostate cancer and if there were an easy genetic test that could pinpoint which prostate cancer sufferers were most likely to benefit from a targeted drug therapy this could be a huge advance. The news release presents hype and hope yet one has to refer to the published study to find any real information, where the researchers report: “We cannot yet determine whether olaparib improves overall survival among patients with metastatic, castration-resistant prostate cancer and DNA-repair defects.”
The release provides no cost information on the drug and the additional testing and additional radiographic work that would be part of this treatment.
The release lacks information on key outcomes such as months of disease-free survival or death rates.
This is the closest we get to any quantification of benefits: “We showed that a subset of men whose tumours had mutations in their DNA repair machinery responded particularly well to treatment with olaparib.”
No harms are mentioned.
Summaries of studies need qualifiers. The trial was a controlled clinical trial (not observational) in that the researchers selected the subjects and decided what to treat them with. But it wasn’t randomized or blinded which made it ripe for potential biases.
The subset of men in this study were dying of prostate cancer. There was no disease mongering about their condition.
We recognize that it can be challenging to sort out and explain complex partnerships in a brief news release but it is better to point out that potential conflicts exist.
Although the release mentions a pharmaceutical backer of the study (AstraZeneca) and lists other funders, we rated this Not Satisfactory because the vast majority of investigators had multiple, complex ties to pharmaceutical makers including some who have patents and other commercial interests in the success of these treatments. These are mostly highly financially conflicted researchers whose conflicts are never mentioned in the news release, even though we know that such financial entanglement will mean that any news release will put the best possible face on the outcome of their research.
This criteria doesn’t apply since all the gene-specified patients were given the same treatment. The release implies that the study enrolled patients whose alternative treatments had failed, but it doesn’t say what those treatments were. We’ll rate this Not Applicable.
The story nods to the availability of the drug used in the study in the UK when it says it “was licensed last year for women with ovarian cancer and inherited BRCA mutations, but so far has not been approved for use on the NHS by NICE or the Cancer Drugs Fund.” However, we aren’t left with any idea if the gene testing carried out here is widely available. That’s a critical point that should have been addressed.
The release states that this is the “First trial to show benefit of ‘precision medicine’ in prostate cancer.” We suspect that this kind of prostate cancer mutation-specific targeting is novel for prostate cancer. It isn’t in the field of oncology in general, however.
There is some unjustified language here that is inappropriate including the phrases: “pioneering drug,” “a milestone in cancer treatment,” ” a significant step forward” and “cutting-edge genomic sequencing, and “highly effective at treating men with DNA repair defects.” Let’s recall that the drug hasn’t been shown to help anyone live longer.