Estradiol levels with AI

Posted by cashemire @cashemire, Dec 5, 2022

Since a recent study (May 2022) found that estradiol was lowered similarly whether the AI (exemastane) was taken daily or every other day, does anyone know what is the aimed at level of estradiol when taking AI ? And can they confirm a blood test would allow one to know this?
Thanks!

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@cashemire

Article attached (Alternative dosing exemestane)
2022 ASCO ANNUAL MEETING
Reduced-Dose Exemestane Noninferior to Standard Daily Dose in Postmenopausal Women With Early ER-Positive Breast Cancer
May 26, 2022
Key Points:
• The aromatase inhibitor exemestane taken 3 times per week is noninferior to the standard daily dose among postmenopausal women with ER–positive breast cancer, considering the primary endpoint of percent change of circulating estradiol.
• The study's primary limitation was the short treatment duration. Because some side effects develop after a few months, conclusions on tolerability cannot be drawn.
Findings from a noninferiority phase 2b biomarker study indicate that the aromatase inhibitor exemestane taken 3 times per week is noninferior to the standard daily dose among postmenopausal women with estrogen receptor-positive breast cancer. Both dosing regimens reduced circulating estradiol by a median of 98% (P = .9). A third group of patients who took exemestane once per week saw their circulating estradiol decreased by a median of 70%. The results will be presented during the 2022 ASCO Annual Meeting by Andrea De Censi, MD, of the National Hospital Galliera, Genoa, Italy, and the European Institute of Oncology, Milan (Abstract 519).
“The lowest dose was slightly inferior, both on the estradiol suppression as well as on the Ki-67,” Dr. De Censi said. “The lowest dose has some activity, which might still be interesting in future studies examining prevention, but our conclusion is that the winner is the intermediate dose, with the same efficacy and presumed lower toxicity than the daily dose.”
This study grew out of concerns that the toxicities associated with standard-dose exemestane may be prohibitive for women taking it for the prevention of breast cancer or for the treatment of early-stage breast cancer. Dr. De Censi noted that the longtime strategy of developing cytotoxic therapies was based on the premise that higher doses of a drug have greater antitumor activity, a paradigm that ASCO and the U.S. Food and Drug Administration believe needs to change.1
“The bottom line of our research is that tolerability is as important as efficacy in prevention,” he said. “When we pursue breast cancer prevention with hormonal drugs given at the same dose as the treatment setting, we often create menopausal and sexual side effects that are intolerable to the majority of these healthy women who are at high risk for developing breast cancer.”
“The bottom line of our research is that tolerability is as important as efficacy in prevention.”—Dr. Andrea De Censi
The long treatment duration for preventive and early-stage treatment is an especially important consideration, Dr. De Censi explained.
“People are generally not willing to take a drug for years to prevent disease if it significantly decreases their quality of life. Other types of preventive drugs are usually well-tolerated, including aspirin, statins, and antihypertensives. That's what we should be working toward in oncology,” he said.
In this multicenter, double-blind, randomized trial, participants took exemestane for 4 to 6 weeks prior to their initial surgery. Three dosing regimens were used: (1) the standard 25 mg per day; (2) 25 mg 3 times per week; or (3) 25 mg once per week for the presurgical period. Investigators collected blood and tissue biomarkers at baseline and during the final visit.
The study's primary endpoint was a noninferiority percent change of circulating estradiol compared to the standard dose. Secondary endpoints included the change in expression of the prognostic markers Ki-67 and progesterone receptor (PgR) in cancer tissue, blood sex hormones, and toxicity.
The authors observed no differences between the daily and every-other-day groups for estrone, total estrone, and estrone sulfate levels. The once-weekly arm also showed some modulation in all hormones, but the changes were less significant than in the other 2 groups.
Additional findings included reductions in all arms of Ki-67 and PgR, although the reductions were not statistically significant among arms. The median change for Ki-67 was −5.0% vs −7.5% (P = .124) in the every-other-day arm and the daily arm, respectively. For PgR, the reduction was −9 vs −17 (P = .246), respectively. The authors found that both adverse events and menopausal symptoms were similar in all arms.
Ultimately, 173 women were evaluable for response out of 180 participants, which Dr. De Censi characterized as one of the study's strengths.
“The number of patients was reasonably high for a biomarker window-of-opportunity trial, and so the study was powered for the primary endpoint,” he said.
The study's primary limitation was the short treatment duration. “Side effects tend to develop after a few months, so our data cannot draw definitive conclusions on the tolerability of the lower doses,” Dr. De Censi said.
In the future, Dr. De Censi would like to see a longer trial with a larger participant pool, but he is aware of the funding challenges that studies of this type face.
“Pharma companies do not have an incentive to fund this type of research on generic drugs, so we need public funding agencies to support this work,” he said. “I'm proud that the U.S. National Cancer Institute funded our work due to its public health implications.”
Dr. De Censi believes that this study has immediate clinical utility.
“In my clinical practice, when my patients do not tolerate exemestane well, I propose that they take it every other day instead—and many, many times, patients are happy,” he concluded.
— Darcy Lewis
Reference
1. U.S. Food and Drug Administration. Getting the Dose Right: Optimizing Dose Selection Strategies in Oncology – An FDA-ASCO Virtual Workshop. Updated May 2, 2022. Accessed May 5, 2022.

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Thank you so much for sharing! I meet with oncologist next week and will ask as I believe national oncology conference was held this week. I am very anxious about quality of life while taking AI's. I'm 57 yrs and just starting on this journey.

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@semurrey

Thank you so much for sharing! I meet with oncologist next week and will ask as I believe national oncology conference was held this week. I am very anxious about quality of life while taking AI's. I'm 57 yrs and just starting on this journey.

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If you can, do post what you learn! My surgeon/oncologist was away at a conference this week, maybe the same one!

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@anjalima

That’s an interesting finding about women trying to get pregnant!

I’m 99 and 98% estrogen positive ( two tumors) so I’m reliable about taking the meds. I did not need chemo and I declined radiation ( was questionable) so this is my one post surgical remedy so to speak. I’m grateful that I’m not having any observable side effects right now … just started month 8.

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Thank you.

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If you read this carefully, you will notice this:

"The authors found that both adverse events and menopausal symptoms were similar in all arms."

I have been speculating about this for years and often on this forum.

The Femara insert says that 20% of the normal dose reduces estradiol below detectabel levels. Eight years ago I asked my oncologist about taking it alternate days and was given permission (I stayed with full dose).

So logically, if estradiol is reduced enough to be effective, side effects would be the same regardless of the dose, right? Because side effects are from estrogen suppression. Including menopause-like effects and many others.

I hope people read that study carefully because it confirms side effects were the same with the lower dose. I don't see how it makes any difference what the dose is, if the drug suppresses estrogen at any level of dose.

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@windyshores

If you read this carefully, you will notice this:

"The authors found that both adverse events and menopausal symptoms were similar in all arms."

I have been speculating about this for years and often on this forum.

The Femara insert says that 20% of the normal dose reduces estradiol below detectabel levels. Eight years ago I asked my oncologist about taking it alternate days and was given permission (I stayed with full dose).

So logically, if estradiol is reduced enough to be effective, side effects would be the same regardless of the dose, right? Because side effects are from estrogen suppression. Including menopause-like effects and many others.

I hope people read that study carefully because it confirms side effects were the same with the lower dose. I don't see how it makes any difference what the dose is, if the drug suppresses estrogen at any level of dose.

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@windyshores “ So logically, if estradiol is reduced enough to be effective, side effects would be the same regardless of the dose, right? Because side effects are from estrogen suppression. Including menopause-like effects and many others.”
I’m thinking about this statement …. If I took say Ibuprofen & and took 8 all at once vs spreading over a 24 hour period the side effects would be different. There is something about taking more (80%) & less (20%) that the side effect is the same is not clear. I might be missing something. Maybe time release into our bodies plays a role. Is full dose more effective against estrogen than the 20%.?
I am not advocating for or against AIs as it is purely personal as all our bodies are so very different. Side effects get discussed a lot bit I’m not hearing do much about effectiveness. My doctor could not tell me if Anastrozole was actually working .. said they take it for granted. That not a very scientific or medical studied answer.

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@sequoia

@windyshores “ So logically, if estradiol is reduced enough to be effective, side effects would be the same regardless of the dose, right? Because side effects are from estrogen suppression. Including menopause-like effects and many others.”
I’m thinking about this statement …. If I took say Ibuprofen & and took 8 all at once vs spreading over a 24 hour period the side effects would be different. There is something about taking more (80%) & less (20%) that the side effect is the same is not clear. I might be missing something. Maybe time release into our bodies plays a role. Is full dose more effective against estrogen than the 20%.?
I am not advocating for or against AIs as it is purely personal as all our bodies are so very different. Side effects get discussed a lot bit I’m not hearing do much about effectiveness. My doctor could not tell me if Anastrozole was actually working .. said they take it for granted. That not a very scientific or medical studied answer.

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@sequioa you can't really compare dosing of ibuprofen and aromatase inhibitors. I don't know if you saw the study elsewhere in this forum that showed alternate days to be as effective as daily but side effects were the same. I do wonder if dosing will change at some point (to half of what it is now). The Femara studies showed effectiveness with 20% but doubt that will become the practice.

Docs rely on standards of care established by studies. They should refer you to studies, I think, but blood tests aren't very useful to determine effectiveness.

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@windyshores

@sequioa you can't really compare dosing of ibuprofen and aromatase inhibitors. I don't know if you saw the study elsewhere in this forum that showed alternate days to be as effective as daily but side effects were the same. I do wonder if dosing will change at some point (to half of what it is now). The Femara studies showed effectiveness with 20% but doubt that will become the practice.

Docs rely on standards of care established by studies. They should refer you to studies, I think, but blood tests aren't very useful to determine effectiveness.

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@windyshores I wasn’t actually comparing ibuprofen & AIs as they are two different meds. Poor example I guess. My point was if you took any med all at once vs. taking as prescribed you’d probably have side effects. Again I’m not stating this well. Sorry. Is blood tests which aren’t very useful how they -researchers & doctors – actually determine effectiveness. I’m interested but not for sure if there is an answer. I know they’ve done studies and I’m glad that there is medication that helps breast cancer patients but one size – I don’t believe – fits all. How does an oncologist decide which AI to prescribe to a patient. Maybe the last sales person that gave him the last info on their drug at their pharmaceutical company. I don’t want to drag this out further but these are some of the areas of my concern. I’ll drop this now. Thank you @windyshores for the input.

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@windyshores

If you read this carefully, you will notice this:

"The authors found that both adverse events and menopausal symptoms were similar in all arms."

I have been speculating about this for years and often on this forum.

The Femara insert says that 20% of the normal dose reduces estradiol below detectabel levels. Eight years ago I asked my oncologist about taking it alternate days and was given permission (I stayed with full dose).

So logically, if estradiol is reduced enough to be effective, side effects would be the same regardless of the dose, right? Because side effects are from estrogen suppression. Including menopause-like effects and many others.

I hope people read that study carefully because it confirms side effects were the same with the lower dose. I don't see how it makes any difference what the dose is, if the drug suppresses estrogen at any level of dose.

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But the point of the study was in fact to examine whether a lower dose would be as effective in lowering circulating estradiol because the authors suggest a lower dose would presumedly result in lower toxicity (and therefore fewer nasty side effects). The lower dose was just as effective apparently but a longer follow up period needed to examine tolerability (SE issue). Personally I’d choose a lower dose if equally effective and I like that they point out that researchers are now questioning the premise that higher doses in general are necessarily better. (Big pharma won’t be on board with this!) Thanks for yr input!

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@anjalima

Half life of Anastrozole is 50 hours!

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Given the relatively long half-life of anastrozole, and my low BMI, I am taking it every other day. My oncologist says that taking it as I am is better than not taking it at all. He has written in his medical notes that I am taking it on alternative days "by preference." I find that the side effects are somewhat reduced but estrogen deprivation still takes its toll. An official study on dosage for all AIs would be great. There was a small Italian study on low-dose tamoxifen that found that 5mg was as good as 20mg for prevention and reducing adverse SEs.

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Again, the study above says side effects were the same for all doses tested. Not sure how this relates to the other comment in the study about toxicity.

The insert that comes with Femara states that 20% of the dose reduced estradiol below detectable levels. My doc okayed every other day.

The question would seem to be, is estrogen suppression the only reason for side effects? If the study found similar side effects at all doses tested, it would seem so, but that is the question I wondered about.

I don't know if side effects would be better on a lower dose. I didn't have bad ones on the full dose so I stuck with it for 5 years.

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