This story describes the upcoming commercialization by Genomic Health and Epic Sciences of a diagnostic blood test which could help determine whether men with advanced prostate cancer should receive new-generation drugs or chemotherapy. The test detects whether the genetic variant AR-V7 is present in tumor cells circulating in the blood stream, and a study in JAMA Oncology found that drugs which target androgen receptors are not as effective as chemotherapy for tumors with the AR-V7 variant.
The article does a good job of explaining how this new approach could not only lead to better outcomes for patients by enabling clinicians to tailor treatments to individuals, but could also save money being spent on an expensive class of drugs that would not work for some patients. The story is careful not to overstate how useful the test would be in practice, since there have not yet been randomized clinical trials to quantify the impact on patient survival.
However, readers are left somewhat in the dark about how strong the evidence is in favor of the test, and the companies’ claims that there is enough evidence for the test to move into the clinic based on a fairly small retrospective study should have been interrogated.
Moreover, readers are not made aware that the lead author has significant ties to the makers of the prostate cancer drugs in question, and the majority of the co-authors are employees of Epic Sciences. A nod to conflicts of interest and the inclusion of independent experts would have provided crucial balance to a story dominated by commercial concerns.
Prostate cancer is one of the most common types of cancer. While new drugs have significantly extended survival times for men in the late stages of the disease, for some men traditional chemotherapy is a better option, so a diagnostic test that would enable doctors to choose which therapy is best could have a significant impact on patient survival.
The need for independent sources matters here because there has been a lot of hype around the potential for non-invasive “liquid biopsy” blood tests to tailor treatments to individual patients, and lots of companies are pushing to develop tests. It’s important for readers to know when to trust in the promise of new tests, and when not to believe the hype.
Excellent job here. The costs of treatment are a core aspect of the story. The opening paragraph describes how the blood test in question could help determine whether patients should receive “costly new-generation drugs or rely on much cheaper traditional chemotherapy,” and the specific costs of different therapies are detailed early in the article.
Much less information is given about the cost of the blood test itself, though the writer does make it clear that the price is not yet determined. It would have been useful to note the costs of any comparable tests already in clinical use, and to let the reader know how insurance companies deal with new diagnostic tests.
The story says “in a study published last month, patients who tested positive for the anomaly—a variant of the androgen receptor called AR-V7—lived substantially longer if they were treated with chemotherapy than those given the two new drugs.”
However, the story doesn’t provide specifics on what that means in number terms.
The story does not explain harms. However, diagnostic tests are only as good as their sensitivity and reliability, so it would have been good for readers to get an impression of whether the test catches every case of AR-V7, and the likelihood of false positives or false negatives. Even if that information is not yet available, it is important for readers to be made aware of the issue that a false result could lead to the wrong therapy being given.
The story lets us known that this was a relatively small study of 161 patients, and it is described as “retrospective.” We’re also told that the blood test needs validation in large randomized controlled trials. While it may be challenging for readers not well-versed in study design to discern what the limitations of a retrospective study is, and what further information a randomized trial would deliver, these details are sufficient enough to rate Satisfactory.
We also appreciated these words of caution: “In the study, a positive test for AR-V7 didn’t assure patients would respond to the chemotherapy, nor did a negative test promise a response to the Xtandi or Zytiga.”
Advanced stage prostate cancer is a common, life-threatening disease. The article gives an estimate, albeit from the companies behind the test, that 50,000 U.S. men with advanced prostate cancer would be candidates for the test.
No independent expert source is quoted throughout the story. This is problematic not least because representatives of both Epic Sciences and Genomic Health are quoted on the clinical utility of the test, and their claims need to be validated or refuted by experts with no skin in the game. It would also be important to get an independent take on the study itself, the strength of the evidence and whether there were any limitations that should be highlighted.
Additionally, next to no information is given about conflicts of interest. While the lead author’s affiliation is given as Memorial Sloan-Kettering Cancer Center, the majority of co-authors of the study are employees of Epic Sciences. This surely warrants a mention so readers are not given the false impression that the company had no role in the study. Moreover, the lead author Howard Scher has received research funding, personal fees and non-financial support from all the companies behind the prostate cancer drugs in question. Despite the fact that the blood test would theoretically identify patients who would be better off not receiving the drugs, Scher has highly relevant conflicts of interest, thus increasing the need for independent expert sources.
The article does not explicitly describe whether there are other methods of detecting AR-V7, though it is implicit that AR-V7 has not been used clinically as a biomarker before, and two other companies developing a similar test are mentioned. The story is based around whether using AR-V7 as a biomarker could lead to better outcomes than current clinical standards, so the comparison to the “status-quo” alternative is thoroughly explored.
It is made clear that the blood test is not currently available, and the article gives a prospective date for when the test will be launched.
Since AR-V7 is not currently used as a biomarker for treatment of advanced prostate cancer, it is clear enough to the reader that this is a new approach.
An important point that is only mentioned in passing is that the test is a “liquid biopsy.” Liquid biopsies have often been hyped as a revolutionary new approach to diagnosing cancer without invasive procedures. However, due to questions over sensitivity and reliability, they have been controversial and are yet to become commonplace in clinical practice, so readers might have benefited from a little more context on this point.
The writer has clearly interviewed his sources and included substantially more information than available from news releases by either Epic Sciences or Genomic Health.