Molliefish, that is awesome.

rljes---BCI is the Breast Cancer Index test. It's run when you hit your 5 year mark. Your original tumor sample is tested. It will tell you what your risk for recurrence is for years 5-10 and whether or not you'd benefit from continuing hormone therapy. Google it and take the info to your doctor (although, for me, a doctor who's never heard of this test would concern me),

NoteRed-- The only SEs I had when I started Tamoxifen was the muscle/joint pain that started at about 3 months. All my other SEs didn't show up till 11 months after I started so yeah, I think you can get them anytime.

Awesome news Molliefish!

I doubt I'll get to 4 or 5 years on tamoxifen.

Just started back on this week after being off 6 weeks, during which time all my SEs, except for an occasional hot flash, went away.

Only taken it since Tuesday and forgot yesterday, but the extreme hot flashes and vag discharge started after the first dose. Waiting to see if the joint and muscle pain returns. If it does, I'm done. I'm turning 68 in 3 days. I'm ok with whatever life the Lord has planned for me, but it's going to be spent without debilitating pain.

Nancy, I completely sympathize with your position. If your SEs all come back and you're tempted to just say "No more" I'd support you in that as we all have our own journeys. But before you do, I'll just second what Runor said as well, since my MO told me the same as well, "Some tamoxifen is better than none.".

This is the info regarding the half-life (time it takes for all of the med to exit the system) for Tamoxifen metabolites:

https://www.accessdata.fda.gov/drugsatfda_docs/label/1998/17970.pdf

So given this information, if I understand the facts correctly, if a patient is taking 20 mgs daily (whether 2 10 mg tabs or 1 20 mgs) for at least 4 weeks, they could stop treatment and there would still be Tamoxifen in their system up until Day 14. Perhaps your MO could give you more info on taking a smaller dose less frequently? Again, IMO and my MO's, something is better than nothing. Wishing you the best on your journey.

**Side note - I was surprised to read at this link, listings of many of the studies that have been done on Tamoxifen. I'll definitely be going back and reading over these as many of them I was not aware of.

rljes that may be the route I go if I do try tamoxifen.

If I understand the role diet & exercise play in reducing the risk of recurrence, then I'm getting a 40% drop right there. I'm low risk, not sure adding tamoxifen in there is worth it especially if it ends up curtailing the level of fitness I currently maintain.

But my MO was pretty definite about his preference that I take it.

Thanks Runor and Spoonie for the info.

I can tell you that it took 4 weeks to find total relief of the SEs when I stopped taking the tamoxifen. And I toyed with the idea of starting back with 10mg, but I wanted to find out if it really is the different manufacturer and not just any tamoxifen. So since I'm back on Mayne/Teva, I'm going to try and stick with it. It took 5 months for me to get the pain I could no longer tolerate. Whether it was the switch to a different manufacturer or just that long for tamoxifen to start bothering me is anyone's guess.

If the pain returns, I will go off of it again until the pain subsides and then try the 10mg. I could also do a lot better with diet (I have a terrible sweet tooth and carb craving) and exercise. I wear a fitbit and average 5000 steps a day, but I should be getting 10000. The only place I get that is Florida where I walk every morning around 2 miles. Here I go to yoga once a week. We live in a hilly area and my hips can't take the inclines. I know I need to force myself to walk every day at least a little bit.

My onc was fine with me not taking it at all if that's what I decided. So I can't imagine him objecting to taking half dose. I don't see him until November so I'll have lots of time and lots of things to try before then.

In my thinking, just the fact that tamox stays in your system for a whole MONTH after taking the last pill leads me to believe 20 mg is not neededto be effective. Based on that fact alone, and all the recent studies that have shown that 10 or even 5 mg is just as effective, I'm sticking with 10mg per day. No one will ever bother to study the lowest effective dose for invasive because tamox is so cheap and no one cares about women's quality of life. I'll bet if it were men, something would be done!

Hi All,

For those it applies to (and perhaps nobody on this topic), you may be interested in taking a look at this research news we wrote up: Low-Dose Tamoxifen May Be an Option to Reduce Risk of Recurrence, Invasive Disease After NON-Invasive Breast Cancer.

An obvious reminder is to please consult your treatment team before making any changes. They will have the full picture of your unique situation and be able to guide you to the best decision for you.

The Mods

I'm reading an article about low dose (not the one posted by the mods) and it says blah, blah, blah tamoxifen is not universally effective among women, some having more benefit and some having little to no benefit..blah, blah, blah.

Uh...wait a minute. Are you telling me that my oncologist happily placed a bottle of tamoxifen in my hands and sent me on my merry way with NO CLUE WHATSOEVER if my body even metabolizes this drug effectively? So, even at my self administered low dose I may still be placing myself at the very real harm associated with tamox while having no clue whatsoever if I am gaining any benefit at all? So, is it correct to say that my Oncoscore might be a whole lot of phooey if no one tested how well my body metabolizes tamoxifen? Isn't that like pushing someone out a plane and telling them the parachute will save them, as long as it's not the one with the holes in it. Well thanks a loooo

oooooo

ooooottt! (splat)

I don't know. Maybe Oncotype does test for efficiency of metabolizing tamox? Maybe my report card should have said, happy news, you are a whiz bang expert at tamoxifen metabolizing. OR it should have said, too bad for you, you suck at algebra AND tamox metabolization.

So they are sending us all out to take a drug and really, they have no stinking clue if it's even going to do us a lick of good since it is not UNIVERSALLLY EFFECTIVE!!! This calls for alcohol.

I agree that it's frustrating and disturbing, Runor. When I learned the fact that you speak of, I specifically asked both of my MOs last Fall for the test that shows if I am a decent metabolizer of Tamoxifen and was denied by both doctors. They say there isn't enough evidence yet supporting the CYP2D6 test. I think it's a bunch of hooey and was, IMO, rightfully gobsmacked. But like the rest of us, I said "ok" and thought "Something is better than nothing. <fingers crossed my body is actually using it>" Ugggh.

Metabolism and transport of tamoxifen in relation to its effectiveness: new perspectives on an ongoing controversy

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4319217/

"Abstract:

Tamoxifen reduces the rate of breast cancer recurrence by approximately a half. Tamoxifen is metabolized to more active metabolites by enzymes encoded by polymorphic genes, including cytochrome P450 2D6 (CYP2D6). Tamoxifen is a substrate for ATP-binding cassette transporter proteins. We review tamoxifen's clinical pharmacology and use meta-analyses to evaluate the clinical epidemiology studies conducted to date on the association between CYP2D6 inhibition and tamoxifen effectiveness. Our findings indicate that the effect of both drug-induced and/or gene-induced inhibition of CYP2D6 activity is likely to be null or small, or at most moderate in subjects carrying two reduced function alleles. Future research should examine the effect of polymorphisms in genes encoding enzymes in tamoxifen's complete metabolic pathway, should comprehensively evaluate other biomarkers that affect tamoxifen effectiveness, such as the transport enzymes, and focus on subgroups of patients, such as premenopausal breast cancer patients, for whom tamoxifen is the only guideline endocrine therapy."

Tamoxifen Therapy and CYP2D6 Genotype

https://www.ncbi.nlm.nih.gov/books/NBK247013/

"The CYP2D6 enzyme metabolizes a quarter of all prescribed drugs and is one of the main enzymes involved in converting tamoxifen into its major active metabolite, endoxifen. Genetic variation in the CYP2D6 gene may lead to increased ("ultrarapid metabolizer"), decreased ("intermediate metabolizer"), or absent ("poor metabolizer") enzyme activity. Individuals who are intermediate or poor metabolizers may have reduced plasma concentrations of endoxifen and benefit less from tamoxifen therapy.

At this time, the FDA-approved drug label for tamoxifen does not discuss genetic testing for CYP2D6 (Table 1) (1). The National Comprehensive Cancer Network (NCCN) Breast Cancer Panel does not recommend CYP2D6 testing as a tool to determine the optimal adjuvant endocrine strategy (Table 2), and this recommendation is consistent with the 2010 update of the American Society of Clinical Oncology (ASCO) Guidelines (the most recent update, 2014, does not discuss pharmacogenetic testing) (2, 3).

The Clinical Pharmacogenetics Implementation Consortium (CPIC) recently published updated guidelines for the dosing of tamoxifen based on CYP2D6 phenotype, with therapeutic recommendations for each metabolizer phenotype (Table 3). For CYP2D6 poor metabolizers, CPIC recommends using an alternative hormonal therapy, such as an aromatase inhibitor for postmenopausal women; or an aromatase inhibitor along with ovarian function suppression in premenopausal women. This recommendation is based on these approaches being superior to tamoxifen regardless of CYP2D6 genotype, and the knowledge that CYP2D6 poor metabolizers who switched from tamoxifen to anastrozole do not have an increased risk of recurrence. The CPIC recommendation also states that higher dose tamoxifen (40 mg/day) can be considered if there are contraindications to aromatase inhibitor therapy; however, the increased endoxifen concentration among CYP2D6 poor metabolizers treated with a higher tamoxifen dose does not typically reach the level as in normal metabolizers (4)."

I did take the genetic test for CYP2D6 (OneOme), provided by my MO, and found out I was an intermediate metabolizer for Tamoxifen. So my hopes of maybe taking less (I so wanted to try and go down to 10 mg) probably won't happen. My MO for sure wants me to be very careful and contact her if there are any supplements I am interested in taking that could reduce the T efficacy further. So who knows if the test really tells us. When I researched, results were all over the place.

Hi, an update on my starting up with a low dose regime..to re-cap, after 3 years on Arimidex and 20% loss of bone density!!! My MO said Arimidex failed me, I got a 3 month break and then he started me on tamox, 10mg. I cited the new studies of 5mg as I am DCIS...and given the bad SEs of Arimidex started off slowly.

Two weeks 5mg every other day, 2 weeks 5mg every day. When I made my pills up for this week I was going to decide if I would up it to 5 somedays 10 others...but I am already having minor SEs (vag discharge) so will stay at 5 for a couple more weeks. Current SEs are within reason, but it appears to me that this low dose is being acknowledged by my system so maybe that is enough.

My next stage up was going to be 5mg/10mg every other day...but as I said, I plan to wait at least two more weeks before increasing from 5mg a day.

After a cool week or so, summer has slammed back into town...already 90! Happy Monday, TT

Elephant, I don't know about universal effectiveness of any drugs. That is actually a good question and a HUGE one!

Rah, this comes from my unscientific and somewhat gin soaked mind. If you are waterproof, it doesn't matter if someone dribbles a teaspoon over your head or turns a fire hydrant on you. Waterproof is waterproof. If you do not metabolize tamoxifen, you do not get more benefit from taking more of it. It's not a bettering ram - at least I don't think it is. Maybe it's like vitamin C in that your body will only absorb as much as it's going to absorb and the un-used amount of vitamin C is just peed out. (if you have bladder infections take more than the suggested dose of vitamin C, it ends up in your bladder making an acidic environment that is hostile to germs, I did this for years on the advice of my doc). I may be thinking wrong but if you are a poor metabolizer, MORE tamoxifen in your body is just wasted and does not change your body's ability to make use of the drug.

Nancy, fitbits can tell you how much sleep you get? Really? Tell me more about this. I need to know.

motiv fitness rings track my sleep and resting bpm too. Love it!

runor

I literally call my sister Darth Vader everytime we vacation and sleep in the same hotel room, after she puts on that machine! I know that sound well!

If you are really interested in the sleep functionality, I actually got better sleep info on a cheap Fitbit knockoff called Very Fit Pro. It is less fancy than a Fitbit but it got the job done for about $20!

Beyond steps and calories, it tracked hours of sleep, times that you woke up in the middle of the night, deep sleep vs. light sleep..it was quite amazing, and I only bought it for the step tracking! I didn't want to spend much until I knew that I would like a fitness tracker. All of the info was stored in the app.

I still use that Very Fit Pro device, along with my Motiv ring...sometimes I just don't want to wear a watch. I've used both together and I actually think that the VeryFitPro is more accurate on steps. The Motiv ring tracks total sleep hours, restless hours and resting heart rate. I bought it for the fitness tracking more than sleep tracking so that basic info works for me. The Motiv ring cost just under $200, uses an app and had a lot more detailed functionality than the Very Fit Pro.

I have a friend who is a doctor who always reminds me that these devices are not NASA-accurate but they they are pretty good even if flawed. I'm not launching a rocket or training for the Olympics!

Fitbit likely has a lot of options for sleep and fitness, at various prices, but I never got around to it!