Tamoxifen decisions
Is it at all surprising that, given these odds, many women who are judged to have a higher risk of getting breast cancer are refusing to take tamoxifen as a preventative? The only surprising thing is that anyone would find it surprising.
Here are the stats:
..[A]mong 1,000 similar women [judged to be at slightly higher risk than average of developing breast cancer], 19 would be expected to develop breast cancer over the next five years.
If those women all took tamoxifen, however, 9 of those women would avoid breast cancer ”” and, as a bonus, 13 would avoid broken bones from osteoporosis.
It is true that tamoxifen can have side effects, some of them serious. Among 1,000 similar 52-year-old women, the drug would be expected to cause 21 additional cases of endometrial cancer, a cancer of the uterine lining that is typically treatable when caught early. An additional 21 would develop blood clots, 31 would develop cataracts and 12 would develop sexual problems. And while more than half of the 1,000 women would naturally develop hormonal symptoms like hot flashes, changes in vaginal discharge or irregular periods, tamoxifen would cause those symptoms in about an additional 120 women.
So, there would be a significantly higher risk of developing another cancer (albeit one easier to successfully treat) and potentially fatal blood clots, as well as a much higher risk of developing a host of other symptoms that would impact negatively on quality of life. All to reduce a breast cancer risk from 19 per thousand to 10 per thousand. And the study doesn’t even say how many of these breast cancer cases would likely be treatable and survivable. Nor does it compare death rates in the groups; I wonder why, since that fact seems extremely relevant.
I’m not knocking the recommendation. I just think the correct decision is hardly a slam-dunk. Both prospects sound pretty dreadful, especially for women who are relatively young.
This is a good intro to why “preventive” health care does not save us money. To prevent breast cancer in 9 women, 1000 women must take the drug and it is not free and it is not cheap. Preventive Tamoxifen causes twice as many cases of endometrial cancer, treatment of which is not free or cheap, as the number of breast cancers it prevents.
Beware of glib facts. Most folks will sit straight up when told that TMX will lower the risk of breast cancer by 47% (9/19). So it does. But fuller info puts such issues in proper perspective, does it not?
Adjuvant TMX to prevent a breast cancer recurrence is an entirely different situation.
But to take it purely preventively is hard to favor.
There’s also more to it than that. The treatement as well as the mortality of endometrial would have to come into play as well. It’s treatable, but patients would need to be told what it’s mortality rate would be relative to breast cancer.
Furthermore, the risk of the treatments for endometrial vs. breast cancer also need to be weighed in. And yes, while they’re both cancer, I don’t know if the same chemotherapy regiments (presuming one would be used) apply to both. I actually suspect it’s not so, although I don’t know for certain.
Informed risk is indeed the keyword here, but understanding the information would be difficult. There are some seriously intertwined risks involved, and sorting them out would be difficult.
Gah… I hate thinking about this, but maybe an oncology practice would be served by a risk/benefit analyst, a sort of “oddsmaker”. That’s a bitch of a calculation to make on one’s own, and that’d be pretty time consuming for the practitioner to sort out as well.
I was told last week that the death rates are exactly the same for those taking tamixifen or not. It just decreases the rate of reoccurence.
My sister took it and the cancer reoccured anyways.
I didn’t know all the side effects but I’m not taking it for my early stage breast cancer and my doctor said more women are opting out. If he insisted I would have taken it.
I just have to do radiation.
It’s really not a big deal. Just make sure you get digital mammograghy… much better pictures. Also, it is probably true that Jewish women have a higher rate of breast cancer.
El: It is the doctor’s professional responsibility to “sort out” the odds. That’s part of the job! Trouble with playing the odds is the patient just plays once, making a yes or no, go or no go decision. Playing the odds is a strategy for multiple bites at the apple, not one. Works better for the doc than for patient Jane Doe.
There is a profound difference between managing individuals and managing populations.Population outcomes guide individual care but do not predict individual outcomes. It pains me to belabor the obvious; forgive me.
Tom, your point is important enough that you divert me from my intended comment. Individuals vs. populations. Yes, and that accounts for much of the reasoning that objects to ever more condoms being placed on ever more bananas and calling it sex education. The school must think of populations, but parents, churches, and friends must think of the individual.
Gaaah! I just read the NYT piece. and it proves my point about glibness: starts off by saying the drug cuts cancer risk in half (see my earlier post). And proceeds to marvel, with tedious verbosity, that women “at risk” ain’t bein’ persuaded.
The most flagrant personally experienced glibness about cancer therapy was by an oncologist touting hideously toxic, sometimes fatal, biologic therapy for metastatic melanoma some yrs ago: said it increased median survival 50%….From 2 months to 3 months!
Tom’s quite right that the NYT is falling for (or playing) a classic statistical illusion, while it is women who are seeing the situation more clearly.
It’s called “denominator neglect” — the tendency of people to focus on the numerator and ignore the denominator. For instance, in studies people prefer a gamble of 9 out of 100 to 1 out of 10.
One can legitimately say that reducing 19 to 10 is ~50% improvement. However, when placed in context of of 1000, it’s only the difference between a 2% risk and a 1% risk.
All this is very strange. A drug with so serious side effects should never be used for preventive treatment of healthy individuals. This violates the first principle of medicine: “Do not inflict harm”.
There are way more numbers games played in medicine than most of you can imagine. For example, most chemo docs will tell a premenopausal woman who’s had a 9mm cancer excised that the benefits of adjuvant (to prevent recurrence) chemo are marginal, but if it’s one (1) mm larger, adjuvant chemo is indicated.
Now, keep in mind that adjuvant chemo reduces the risk of breast cancer recurrence in Stage I (=less than 2cm= 20mm) very modestly, from 6% to 4%. That means 100 women get chemo in order to save 2. This is, however, today’s standard of care, and docs who don’t observe it will get hammered in a malpractice suit brought by an untreated woman who relapses. Thus, getting paid for treating 100 women to help 2, they all do it.
TMX is causing a liver inflammation that my Gastro says I can’t live with for another 3.5 yrs while I finish my treatment.
My oncologist says I have to finish the TMX for at least another year, or I’m at great risk of relapse. I had Duc. Car. Insitu, not even stage I.
Isn’t obvious that I need my liver a lot more than my breast? Can’t they just scan me more often??
Medicine is so illogical. And I’m not in the states, I’m in Israel where I don’t think these medicos are so worried about malpractice.
Michal-
Medicine is not inherently illogical. You have a problem of conflicting agendas: ACTUAL liver problem v. POTENTIAL breast problem. You are of course correct in your liver v. breast analysis.
TMX causing hepatitis? Your gastro doc must be made to be very sure all other causes have been ruled out. Your oncologist cannot guarantee you the outcome desired in taking TMX for the period prescribed. And the two docs must confer together about you and your care.
Michal: This article was about preventative tamoxifen for woman who have never had breast cancer but are judged to be at greater risk for it. I don’t have the stats for recurrence, but I believe the case for tamoxifen is quite a bit more powerful in women who have had breast cancer and are taking it to prevent recurrence. That said, I have no idea what they would be with someone who has had your type of cancer. I wish you the best of luck, however, in making this decision and for your future health.