Secondhand Smoke and Breast Cancer?

[joesixpack]

I just read an artical in USA Today (hey, it was in the breakroom and more interesting than the Avon catalogue) that said there is a new study that shows a 90% risk increase of breast cancer among women exposed to secondhand smoke. Though I'm sure secondhsnd smoke isn't a good thing (I quit smoking when my son was born, so don't think I'm defending secondhand smoke here), my gut tells me that this study is somehow flawed. I'm no epidemioligest ( as you can tell by my spelling of the word) but wouldn't exposure to secondhand smoke put French women in a very high risk group? Do french women suffer from breast cancer at almost twice the rate of American women?

http://www.usatoday.com/news/health/2005-03-08-smoking-breastcancer_x.htm

http://www.usatoday.com/news/health/2005-03-08-smoke_x.htm

Can anyone tell me if this is good science?

 

[Jorghnassen]

Well, it's hard to tell with the partial (as in incomplete) info given in the articles. Though I can answer your question about French women vs American women. The two populations are quite different aside from smoking exposure, and there are many other factors that would make the cancer rates hardly comparable with respect to smoking exposure only.

 

[joesixpack]

I can answer your question about French women vs American women. The two populations are quite different aside from smoking exposure, and there are many other factors that would make the cancer rates hardly comparable with respect to smoking exposure only.

I thought that at first, too, but a 90% risk increase is hardly something that would be lost in the background noise. Or is it? Surely French health officials have done studies on breast cancer. Wouldn't they have enough data to at least make some meaningful comparason? A 90% risk increase is quite a bit, non?

 

[Rob Lister]

I thought that at first, too, but a 90% risk increase is hardly something that would be lost in the background noise. Or is it? Surely French health officials have done studies on breast cancer. Wouldn't they have enough data to at least make some meaningful comparason? A 90% risk increase is quite a bit, non?

I can't say because I'm not one of them their epodemowhatevers either but I am skeptical for many reasons. One huge red flag being...

The 1,200-page report analyzes new data on the extent of Californians' exposure to secondhand smoke and more than 1,000 studies of health effects from secondhand smoke.

emphisis mine.

 

[Jorghnassen]

I thought that at first, too, but a 90% risk increase is hardly something that would be lost in the background noise. Or is it? Surely French health officials have done studies on breast cancer. Wouldn't they have enough data to at least make some meaningful comparason? A 90% risk increase is quite a bit, non?

Not necessarily. From the second article, that 90% seems to be the upper bound of an interval estimate, and basically, it says that exposed women have (at most) 1.9 times (1.26 times at least) the risk to get breast cancer as unexposed women. It doesn't look that impressive if you put it that way does it? A real epidemiologist would know how to interpret those numbers better....

 

[CBL4]

This seems like a bogus study. From the first link:

The report also gave more weight to toxicology evidence from animal studies than previous studies by the surgeon general and others

Tobacco companies, in public comments filed with the board, say the report gives little weight to studies that found no breast cancer connection.

Unfortunately, smoking has become so politicized that it is almost impossible to trust any study.

CBL

 

[Jorghnassen]

This seems like a bogus study. From the first link:

Unfortunately, smoking has become so politicized that it is almost impossible to trust any study.

CBL

I wouldn't necessarily call it bogus, but the reporting is clearly trying to, shall we say, accentuate what the study really shows (though data collection, analysis and actual conclusions might also be flawed).