Thursday, July 12, 2007

This week in NEJM

So I have been reading about how the new article in the New England Journal of Medicine shows that BRCA gene mutations are not worse than sporadic breast cancers due to non-BRCA mutations.

If you look at the article you will see that there are many reasons why this is flawed thinking. But more importnatly it flies in the face of another study which actually showed and increased risk in worse outcomes with BRCA1 mutations.

So on closer inspection what was the NEJM article about?

They took all breast cancer specimens available in Israel's National Healthcare repository and looked for 3 I repeat 3 FOUNDER MUTATIONS....... This immediately makes the study invalid to comparison on women who have non ashkenazi mutations, especially if they are not founder mutations.

Secondly they analyzed outcomes retrospectively. This is a notorious way to get confounding results as well.

Thirdly this study did not have interpretable data regarding estrogen or progesterone receptor status.......This is a big deal!!!

And Lastly,
"We had 16-year follow-up data on mortality and incident cancers, but information on the cause of death was available from the Central Bureau of Statistics only for deaths that occurred before 2000." None from after 2000........

The Gene Sherpa Says: Before bloggers and press go off half cocked in this interpretation we need to be careful in how we evaluate this study. This ONLY means if you are an ashkenazi jew from Israeli heritage and have one of 3 founder mutations, then you are not more likely to have adverse outcomes than ANYONE else who is Israeli and Ashkenazi with non founder mutation breast cancer....That's IT. Nothing else can be extrapolated here. To those who are.....tread carefully...Because you are misleading the public!

1 comment:

clingenblog:ramunas said...

Hello, Steve - I totally agree with you - this study definitely has a serious limitation - also tried address it at my post