Oncotype DX and risk for clinically significant prostate cancer

Last September we asked whether the Oncotype DX test for risk of prostate cancer developed by Genomic Health was “ready for prime time”. In a media release issued earlier this week, the company said that it was. However, there are a number of unresolved issues that are likely to impact the uptake of this new test.

According to a media release and “other informational assets” issued by the company on Wednesday, Genomic Health will be

making its Oncotype DX® prostate cancer test available to physicians and their patients today following the presentation by the University of California, San Francisco (UCSF) of a positive clinical validation study at the 2013 American Urological Association (AUA) Annual Meeting in San Diego.

The Oncotype DX test can be used to measure the level of expression of 17 genes across four biological pathways to predict prostate cancer aggressiveness. These test results are reported as a Genomic Prostate Score (GPS) that ranges from 0 to 100 and is combined with other clinical factors to further clarify a man’s risk prior to treatment intervention.

To see the abstract of the specific presentation by Cooperberg et al. (abstract no. 2131, “Development and validation of the biopsy-based genomic prostate score [GPS] as a predictor of high grade or extracapsular prostate cancer to improve patient selection for active surveillance”) presented at the AUA, please click here and then enter the abstract number in the box that says “Search by publication number”).

An article in Wednesday’s New York Times discusses a number of the unresolved issues, starting with whether the data are really as compelling as the company would like to think and moving on to address whether payors will be willing to cover the cost of the test (at > US$3,800 per test). Quoted in the article in the New York Times, even Dr. Peter Carroll of the University of California, San Francisco (the senior author of the study from which data were reported at the AUA meeting) has doubts about just how quickly physicians and patients will accept data from this test, stating that,

Certainly for a group of men it will have an impact. The question is how many men and how many physicians.

The potential of the new test is to be able to distinguish more accurately between the men who can be managed safely on active surveillance for an extended period of time and those who really do need early invasive therapy. The problem with the test is that all of the available data so far are based on analyses of data from patients who went on to have radical prostatectomies, i.e., the comparison is of the effectiveness of the test carried out on biopsy samples to predict the pathological results post-surgery. What we don’t have at this time are any data that tell us, based on a prospective clinical trial, what the outcomes of men have been at 5 and 10 years after decisions about treatment (or active monitoring) were made based on the results of the Oncotype DX test at the time of initial biopsy.

The correlation of the results of the Oncotype DX tests to post-surgical pathological data certainly give us some guidance about the potential of this test, but — from a practical, clinical point of view — many physicians and their patients will want to know just how accurate this test is in prediction of outcomes in the “real world” before they are going to be willing (in their minds) to “put lives on the line.”

4 Responses

  1. Genomic Health (I believe) felt they had to get this test “out the door” because Myriad’s Prolaris test has been out in the market for well over a year. I believe they accelerated their original schedule by almost 2 years. That is not to say that this is not a good test. The head of the PCF, (whose name escapes me at this moment) has had some very good things to say about it.

    To the best of my understanding, this test works the same way as the Prolaris test — with, perhaps, a slightly different set of genes (most will be the same however), and a slightly different algorithm for analysis.

    Myriad has a number of prospective studies underway. I personally find their retrospective methods and data quite convincing. As the old saw goes, no one has ever done a prospective study on the usefulness of parachutes when jumping out of aeroplanes, but we still recommend them.

    I have had major prostate surgery, followed by two minor surgeries to correct issues with the first. (This was prostate reduction surgery, which carries less risk than prostate removal.) I can attest to the fact that you don’t want someone cutting on your prostate unless it is absolutely necessary.

    I personally would pay for this test myself (or probably the Prolaris test, because it has more data) as another piece of data to support my decision to go the AS route, if the other parameters indicating AS lined up, or if the other parameters indicating AS were borderline. I’m glad the tests are out there, so we at least have another option.

    You might say many men couldn’t afford to pay for this test. I disagree with that … most men could afford $3,800 for something as important as avoiding impotence and incontinence if they want to. (Unfortunately, many have developed a mentality that health care should be free or almost free.) So, if a guy sitting in front of his big-screen TV, watching HBO, with a pickup, boat and camper parked in the yard says he can’t afford $3,800 to keep from unnecessarily wearing Depends the rest of his life, I’m not buying it (but, if his junk is more important to him, that’s his choice).

    I’m starting to rant here, but I saw a good example of this in my doctor’s office the other day when I asked for a shingles vaccination. My doctor said I would probably want to check and be sure its covered by my insurance before getting it, because its really, really expensive. I asked how expensive it was: $200. I said, are you kidding? I’m going to risk getting shingles when I don’t have to because I don’t want to pay $200? If I have to, I’ll cancel my DirecTV or cut something else out that’s less important than my good health. (By the way, the other possible outcome of the test is that the cancer is, in fact, very aggressive and you are going to want to do something about it right away … in that case the risk of the disease outweighs the risk of treatment.)

  2. I could not agree more with you Doug. In situations like this we need as many data points as possible to make an informed decision, and this is our health.

  3. So the company is selling a test for almost $4,000 based on a retrospective analysis of [data from] several hundred men that didn’t require FDA approval, doesn”t tell us how often they are wrong or right, but simply gives a percentage result of how many men will have a more aggressive or less aggressive cancer based on final pathology! It also has few published studies and no data about the odds of recurrence, chances of getting metastases, or survival. And yet it is being heralded by many people. I must be missing something here because in my mind it is way too early to be selling this test without much better data about its utility.

  4. I am a patient at UCSF and when the news hit I immediately e-mailed my surgeon. She tried to use a 9-month-old biopsy sample but the company said it should be on tissue that is less than 6 months old, so I am out of luck until my next biopsy (which I was hoping to forestall by taking the test)!

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