BC Drugs Urged for Healthy, High Risk Women - NYT

Athena, I've already had ovarian cancer and a pulmonary embolism along with it. I have LCIS & lobular is notoriously hard to detect. I am upset that I CAN'T take Evista because of the clotting risk. As I am high risk I would welcome the educated decision to be able to take the preventative. It certainly wouldn't be a fear-based and knee-jerk decision on my part.

From the NYTimes article:

"The group estimated that among 1,000 women with an increased risk of breast cancer, there would be 23.5 cases of invasive breast cancer over five years. If the women took one of the drugs, 7 to 9 cases would be prevented over five years.

But an extra 4 to 7 women per 1,000 taking the drugs would develop blood clots during that time, and there would be 4 extra cases of uterine cancer per 1,000 women taking tamoxifen — an approximate doubling of both of those risks."

Okay, so let's do the math on this. 

Without these drugs, 23.5 of the 1000 women will get breast cancer over 5 years. So this means that 976.5 women of the 1000 will not get breast cancer. 

With these drugs, 7 - 9 cases of breast cancer will be prevented over 5 years. But this also means that 14.5 - 16.5 of the women will take these drugs and they will still develop breast cancer, plus they will have exposed themselves to additional serious health risks by taking these drugs and they will have experienced the quality of life side effects from taking these drugs.  And the 976.5 women who never would have gotten BC anyway will also have exposed themselves to the risks and experienced the side effects. 

Of the 1000 women who take these drugs, 4 to 7 women will develop blood clots and 4 will develop uterine cancer (women who would otherwise not have experienced these health issues).  So this means that 8 to 11 women will experience these particular side effects...although I suppose it could be less if it happens to be some of the same women develop both of these conditions together.  

To net it out:

* 1000 women take the drug.  

* 991 - 993 of the women really didn't need to take the drug because they either weren't going to develop BC anyway or because they will develop BC whether they take the drug or not.  

* 7 - 9 women avoid a diagnosis of breast cancer.

* 8 - 11 experience serious health side effects.  

I have nothing against these drugs.  If you've been diagnosed with BC and you have a high risk of recurrence - and particularly, a distant recurrence  - these drugs can be life-saving.  But the risk vs. benefit equation isn't quite a clear for those who have low risk diagnoses and those who have not been diagnosed but are high risk.  It really depends on your recurrence risk level and/or your breast cancer risk level, as well as your risk level for these other conditions.  "High risk" is a big tent, and having a small area of ADH (or even DCIS) or a 2nd degree relative with BC is a lot different than having a high risk diagnosis of LCIS or being BRCA positive.  Unfortunately, it seems that there are too many oncologists who recommend these drugs without taking these important individual factors into consideration. 

One thing to keep in mind, as well, is that - even without tamoxifen - breast cancer cells can- and do spontaneously change receptors.  A friend of mine, who refused tamoxifen the first time for her hormone positive breast cancer, developed a recurrence three years later in the mastectomy scar that was hormone negative.  It can happen.  So, we need to know 1) how often this happens spontaneously vs 2) how often it happens as a result of tamoxifen and is the difference statistically significant.