Full data on ADT + chemotherapy from the STAMPEDE trial now published


Back in May 2015, James et al. reported on the survival benefits associated with androgen deprivation therapy (ADT) + docetaxel-based chemotherapy compared to ADT alone as first-line therapy for treatment-naive men initially diagnosed with metastatic prostate cancer.

This original presentation was given at the annual meeting of the American Society for Clinical Oncology, and we reported on these data at that time. However, the complete results of this component the STAMPEDE trial were just published in The Lancet and will be of particular interest to support group leaders and other prostate cancer educators (quite apart from clinicians responsible for treating such patients). The full text is freely available on line.

In addition, what is also available in The Lancet is the full text of the article by Vale et al. that offers a meta-analysis of all five randomized trials (including the CHAARTED trial, the STAMPEDE trial and the GETUG-15 trial) designed to compare ADT + docetaxel-based chemotherapy to ADT alone in men initially diagnosed with metastatic prostate cancer. This meta-analysis concludes that the combination of ADT + docetaxel-based chemotherapy

should be considered standard care for men with M1 hormone-sensitive prostate cancer who are starting treatment for the first time.

regardless of the cancer load and regardless of any prior forms of treatment other than ADT. Not all clinicians who are experienced treaters of metastatic prostate cancer would necessarily agree with this conclusion as yet (at least here in the USA). However, any hormone-naive patient who is starting treatment for evident metastatic prostate cancer (TxNxM1) should certainly discuss this option with their doctors.

The Vale et al. meta-analysis does note, however, that we cannot yet draw the same conclusion with respect to hormone-naive men men diagnosed with micrometastatic prostate cancer (TxNxM0).

What is very clear, however, is that we have now entered a new era in the initial treatment of men with hormone-naive TxNxM1 disease. Any other alternative form of treatment for such patients will now need to be compared to ADT + docetaxel-based chemotherapy, and this raises all sort of questions about whether the use of drugs like abiraterone acetate (Zytiga) and enzalutamide (Xtandi) in the treatment of such patients prior to ADT + chemotherapy is appropriate at all (outside of a clinical trial).

4 Responses

  1. So does this finally answer the question for low volume met guys? And if so, what is the OS benefit?

    Thanks

  2. Dear Jerry:

    The STAMPEDE trial was not designed to discriminate between men with low-volume and high-volume metastasis, but it was a far larger trial than the CHAARTED trial (with 1,817 patient who had M1 disease at time of randomization). Thus, strictly, no, this trial doers not “finally answer the question for low volume met guys”. Nor does it tell us the overall survival benefit for that subset of men men either. This is why some in the medical oncology community may continue to be resistant to use ADT + chemotherapy early in men with low-volume metastasis (given the side effects associated with chemotherapy).

    And the other thing is that the STAMPEDE trial included no American patients, and there are some in the US medical oncology community who have a hard time accepting data from studies carried out in other countries (yes, even the UK and Switzerland) … however well such trials may have been conducted.

  3. Jerry,

    STAMPEDE collected data on the number and location of metastases, and 61% had at least one non-local metastasis. Perhaps in light of the CHAARTED findings, they will eventually publish a breakout of outcomes by many/few metastasis, or possibly a multivariate analysis using number of metastases as an independent variable.

    There was a significant benefit in terms of failure-free survival for both men with no metastases (M0) and men with any metastases (M1). And the hazard ratios were virtually identical for both groups (0.6). However, that benefit translated into a benefit in overall survival, only among the M1 men. The caveat is that, as of this analysis, mortality was only 14% among M0 men, and much of that may be attributable to comorbidities. The difference in overall survival may show up with longer follow-up.

    It may be that low volume M1 is a distinct phenotype from both high volume M1 and M0, or it may be that the difference noted in CHAARTED will decrease with longer follow-up.

  4. This is in the Dutch news right now. I will now send the link to two Dutch journalists who write about cancer. Thank you.

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