New Study on extended use of Letrozole

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Momine
Momine Member Posts: 7,859
edited December 2016 in Clinical Trials, Research News, Podcasts, and Study Results

In the news today, a new study on letrozole beyond 5 years of either tamox or AI use. The article I read, said the following:

"The result: Women who took letrozole for those extra two years did not experience statistically significant higher rates of either "disease-free" survival or overall survival than those in the placebo group, the study found.

There were some other benefits, however. For example, women who extended their use of letrozole showed a 29 percent reduction in breast cancer recurrence, and a 28 percent reduction in a tumors arising at locations outside the breasts."

Color me confused. If the extended use lowered recurrence and mets, how come the extended use did not show any benefit in terms of DFS or overall survival.

Thoughts?

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  • Racy
    Racy Member Posts: 2,651
    edited December 2016

    I don't understand either, Momine, but I'm continuing for 10 years.

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  • cive
    cive Member Posts: 709
    edited December 2016

    Perhaps because the use of hormone suppressants delay progression but do not affect eradicating the cancer. So women who did not use a hormone suppressants still have them in the bag to use after being diagnosed with mets.

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  • Heidihill
    Heidihill Member Posts: 5,476
    edited December 2016

    Cumulative toxicity of AIs leading to heart disease and bone fractures based on this 2011 report comparing to Tamoxifen which has its own toxicity compared to placebo.

    http://medicalxpress.com/news/2011-08-toxicity-aromatase-inhibitors-lack-survival.html


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  • dtad
    dtad Member Posts: 2,323
    edited December 2016

    Hi all. Maybe I'm wrong but the way I read the study is that there is a reduction in recurrence by 28-29 percent but not a reduction in survival rates. The rationale being that aromatase inhibitors had their own serious SE that could affect survival rates. It is somewhat confusing. Any other ideas?

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  • Momine
    Momine Member Posts: 7,859
    edited December 2016

    Dtad and Heidi, not sure. I read another article in the Guardian on the study, and that seemed to suggest that the letrozole simply delayed the inevitable. The original study doesn't seem to be available anywhere yet, so I guess we have to wait for clarification.

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  • Momine
    Momine Member Posts: 7,859
    edited December 2016

    OK, I sent an email to my doc, who is most likely at the meeting. If he answers anything I can comprehend, I will report back.

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  • voraciousreader
    voraciousreader Member Posts: 7,496
    edited December 2016

    Dec 7, 2016 05:24PM voraciousreader wrote:

    SAN ANTONIO — Despite three new trials examining the extension of adjuvant endocrine therapy in hormone-positive breast cancer, there were no easy answers here at the San Antonio Breast Cancer Symposium (SABCS) 2016. The trials were the NASPB B-42, IDEAL, and DATA studies.

    "I was anticipating a new milestone of knowledge... [but] whether we like it or not, essentially these three trials did not reach statistical significance to demonstrate clear benefit for their respective aromatase inhibitor extensions," commented discussant Michael Gnant, MD, from the Medical University of Vienna, Austria.

    In particular, the NASBP B-42 trial was much anticipated because it examined extending adjuvant therapy with the aromatase inhibitor (AI) letrozole (Femara, Novartis) for 5 years in patients who had initially received 5 years of adjuvant therapy with an AI (either alone or mixed sequentially with tamoxifen).

    "The first extended adjuvant therapy trials (MA-17, NSABP-B33 and ABCSG-6a) investigated AIs after tamoxifen and demonstrated significant benefits for patients. However, those trials did not answer the question, should we also use extended AI treatment after AIs were used in initial adjuvant therapy? This is why NASBP B-42 is so important," said Dr Gnant....

    http://www.medscape.com/viewarticle/872973

    Please register at medscape to read the complete article

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  • Momine
    Momine Member Posts: 7,859
    edited December 2016

    Thanks, Voracious, that is a better article. Still rather confusing, but it sounds as if the doctors are confused as well. I wonder what the differences are, between the 2 studies discussed, in the definition of DFS.

    Completely OT, I am amused that 2 of the 3 doctors quoted are Greeks.

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  • voraciousreader
    voraciousreader Member Posts: 7,496
    edited December 2016

    one of the issues that has been previously discussed by researchers...with respect to the SOFT and TEXT studies as being examples is that most recurrences in ER + HER 2 neg tumors more often than not have late recurrences...10 + years down the road...soooo...you might not see overll survival benefits until many years out from the initial diagnosis...


    The key to all of these studies is to focus on those patients who are deemed at high risk....That said...the genomic studies underway that identify biomarkers.. are the ones that hopefully will shed light on who EXACTLY is at high risk of recurrence. It is those studies that will lead to better clinical recommendations...


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  • voraciousreader
    voraciousreader Member Posts: 7,496
    edited December 2016

    btw...i am posting most of the important San Antonio studies on another thread...

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  • Momine
    Momine Member Posts: 7,859
    edited December 2016

    Found it, thanks!


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  • ErenTo
    ErenTo Member Posts: 343
    edited December 2016

    I wonder if there is any data on various subsets. That might tell us more. Haven't had a chance to look at the papers yet

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  • Momine
    Momine Member Posts: 7,859
    edited December 2016

    Erento, as far as I could understand from the Medscape article posted above, they hadn't found any useful subgroup patterns. But I imagine more work will be done on that.

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  • cp418
    cp418 Member Posts: 7,079
    edited December 2016

    http://www.aacr.org/Newsroom/Pages/News-Release-De...


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  • Momine
    Momine Member Posts: 7,859
    edited December 2016

    OK, my doc wrote back that he understands my confusion, because the doctors are confused themselves about these results. He won't be able to give a more considered opinion, until he reads the actual study. In the meantime he sent along the video of the presentation at ASCO:

    http://ecancer.org/video/5557/extended-adjuvant-endrocine-therapy-with-letrozole-after-aromatase-inhibition.php

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  • Momine
    Momine Member Posts: 7,859
    edited December 2016

    From the video emerges part of the explanation.

    DFS is defined as: local, regional or distal recurrence, cancer in the opposite breast, second, non-breast primary cancer, and deaths from any cause as primary events.

    Breast cancer-free interval defined as: recurrence or appearance of cancer in the opposite breast as a first event, distal recurrence, osteoropotic fractures, arterial thrombotic events.

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  • cp418
    cp418 Member Posts: 7,079
    edited December 2016

    I'm just short of 10 years of taking Letrozole. This winter between the damp cold weather and ongoing joint pain I'm ready to stop. I'll see MO tomorrow and discuss - frankly, I'm not surprised as all these drugs have side effects. Hopefully, I'll be allowed another Prolia injection for my ongoing osteopenia.

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  • TectonicShift
    TectonicShift Member Posts: 752
    edited July 2020

    .

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  • Momine
    Momine Member Posts: 7,859
    edited December 2016

    Tectonic, that is what my PT said as well, and before the studies on extended use had come out.

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