Farm work and breast cancer - bad news...

Canadian researchers have uncovered a correlation between breast cancer in women and working on a farm.

The paper, to be published today in the Annals of the New York Academy of Sciences, says women with farming experience are 2.8 times more likely to develop the disease than non-farmers and that the agricultural link may linger long after a woman has gone on to other occupations. [More]

It is important to understand that a correlation does not imply cause. I'm not denying the link - it is real, and underscores the importance of screening and other tests - but more research may reveal exactly what factor is to blame or even if there is a common causal factor for the two. For instance, women who work on a farm may be subject to particular stresses or well water or other rural factors that could affect their immune system.

Ann Chambers, a professor of oncology at the University of Western Ontario's Schulich School of Medicine and Dentistry, said it was a "good study" that should prompt further research. But Chambers, who specializes in breast cancer, said it was important to understand the association found in the study between cancer and farming does not necessarily mean there's a causal relationship between the two."The real danger that the public has in this sort of thing is that you see an association and then they think, `Aha, working on a farm causes cancer,'" she said. "And the study statistically can't say that. It says there is an association which warrants further study to understand what the cause is."

The only stronger correlation was working on a farm and then working in the auto industry.

What is that about?