Tamoxifen effectiveness

Anonymous

Tamoxifen effectiveness

KathyL624

I see so many women here who have recurred while on tamoxifen. Does anyone have numbers/studies that show how effective it actually is? People here say A.I.s are more effective, but my oncologist has a lot of faith in tamoxifen for premenopausal women. Do less women recur on an A.I.?

keepthefaith

Kathy, you will want to ck with your MO, but I believe Al's are prescribed to post-meno patients, not pre

KathyL624

you are right but I am doing ovarian suppression so I could switch to an A.I

Lisey

Kathy, you need to read the SOFT study... that's where the AI/ooph is coming from. http://www.nejm.org/doi/full/10.1056/NEJMoa1412379#t=article

Basically: At 5 years, 88.4% of the patients assigned to receive tamoxifen plus ovarian suppression remained free from breast cancer, as compared with 86.4% of those assigned to receive tamoxifen alone. Among patients assigned to receive exemestane plus ovarian suppression, 90.9% - so there is a 1.5% increase in women who took an AI over tamox.

When SOFT was planned, it was hypothesized that tamoxifen plus ovarian suppression would reduce the relative risk of breast-cancer recurrence, a second invasive cancer, or death by 25%, as compared with tamoxifen alone, and furthermore, that exemestane plus ovarian suppression would reduce the relative risk by 25%, as compared with tamoxifen plus ovarian suppression. After adjustment for covariates in the multivariable Cox model, tamoxifen plus ovarian suppression resulted in a 22% reduction in the relative risk of breast-cancer recurrence, a second invasive cancer, or death (P=0.03) and a 25% reduction in the relative risk of breast-cancer recurrence, as compared with tamoxifen alone. After a protocol amendment, the comparison of exemestane plus ovarian suppression with tamoxifen plus ovarian suppression, on the basis of a combined analysis with TEXT, showed a 28% reduction in the relative risk of breast-cancer recurrence, a second invasive cancer, or death and a 34% reduction in the relative risk of breast-cancer recurrence in the exemestane–ovarian suppression group (P<0.001).10

Overall, tamoxifen plus ovarian suppression resulted in an absolute improvement of 2.0 percentage points, as compared with tamoxifen alone, in the proportion of patients without recurrent breast cancer at 5 years. In the higher-risk cohort of patients who remained premenopausal after chemotherapy, tamoxifen plus ovarian suppression resulted in an absolute improvement of 4.5 percentage points, as compared with tamoxifen alone, in the proportion of patients without recurrent breast cancer at 5 years; with exemestane plus ovarian suppression, the absolute improvement was 7.7 percentage points, as compared with tamoxifen alone. These observed relative and absolute benefits at 5 years from ovarian suppression plus tamoxifen or ovarian suppression plus exemestane, as compared with tamoxifen alone, compare favorably with the practice-changing results of randomized trials of adjuvant aromatase inhibitors versus tamoxifen in postmenopausal women.16

KathyL624

Thanks Lisey, I know about the SOFT trial. My issue is that I fall into the cohort for which they don't recommend anything but tamoxifen...I did not have chemo and was 38 at diagnosis. To me that 38 is too close for comfort to the under 35 age group for which OS showed benefit. My MO agreed to OS even though she thinks I don't need it so she is favoring me at least staying on tamoxifen while doing the shots but I am worried I am not doing enoug

edwards750

Kathy where are all these women you are talking about?

I am connected to another group and none of them have had a recurrence at all much less with Tamoxifen.

There is no magic pill. I know some women who opted not to take anything and had a recurrence.

It's a crap shoot.

Dian

KathyL624

To be honest "all these women" who had recurrences on tamoxifen I've read about here! Before reading these boards I really thought an early diagnosis meant you would be ok but I know now that is not necessarily true

BarredOwl

Hi KathyL624:

As a layperson with no medical training, I have no idea what the best approach to endocrine therapy or particular drug selection in any specific case should be. This is a highly specialized area with a very large body of literature. The materials below should not be used by anyone to make treatment decisions, but should be used to inform discussions with one's MO. There may be additional and/or conflicting studies that alter understanding or the findings may not apply in the individual case.

The differing adverse effect profiles may play into the recommendations received. For some other considerations, see this Medscape article/interview discussing the recent 2016 ASCO guideline re ovarian suppression. The entirety of the text on page 2 of the article may be of particular interest to you, with two caveats regarding AI's: (1) the first, based on conflicting results from the ABCSG12 trial, POSSIBLY due to a different (slightly lower) risk profile of the study group or other factors (but see, Dowsett below); and (2) the second concerning "incomplete ovarian suppression". Dr. Burstein also comments on how he addresses this in his practice.

Medscape (2016): "Ovarian Suppression in Breast Cancer Patients: Right or Wrong, Depending"

http://www.medscape.com/viewarticle/860383#vp_1

Registration for Medscape is free, but if you prefer, you can access the full-text without registration by googling the title of the article (above).

This recent article discusses the concept of "incomplete ovarian suppression" in much greater detail:

Dowsett (2016), Full-text page:

http://ascopubs.org/doi/full/10.1200/JCO.2015.62.3728

This paper has a somewhat different view regarding the results of the ABCSG12 trial.

- You can access a pdf version (click on "PDF" at upper right of page, and then click on "Show PDF in full window" again at upper right,so you can save a copy.)

- Also, at the bottom of the full-text page, there are links to the full papers for the SOFT-EST study discussed (Bellet, 2016) and for another study. A related feature is behind a paywall, and can be obtained for a nominal fee (currently $2.00) by the PatientACCESS option with registration via the copyright clearance center if of interest.

The 2016 ASCO update that addressed the question of ovarian suppression mentions the concept of "incomplete ovarian suppression" in a number of places, including this quote:

2016 ASCO Update: http://jco.ascopubs.org/content/early/2016/02/11/JCO.2015.65.9573.full.pdf

"The Panel cautioned clinicians that AI-based therapy is only effective in the setting of ovarian suppression or ablation. There are situations in which there may be ambiguity regarding the status of ovarian function, such as in women with chemotherapy-induced amenorrhea, after hysterectomy, with incomplete ovarian suppression, with incomplete compliance with GnRH agonist treatment, or with other pathophysiological conditions. In such instances, tamoxifen is the treatment of choice, as it remains effective regardless of ovarian reserve."

The usual caveats about guidelines not mandating individual treatments, and being snap-shots in time that may not reflect the latest studies, etc. apply.

You may wish to discuss your question with your MO, to gain a better understand his thinking behind the selection of tamoxifen in your specific case, in light of your risk profile and overall presentation.

BarredOwl

[Edited to update J Clin Oncol link to Dowsett]