That's a nice narrative you have going there Edmund Burke, with the ultimate causative agent -oestrogen- being responsible for the risk factors involved in abortion, pregnancies etc.

Nice and neat.

But I am struggling to find a good review or paper that continues that story in the scientific literature. Would you please care to furnish us with some scientific papers on the subject of oestrogen levels and breast cancer that describe the scientific basis of the version of events you are relating to us?

Reviews that support your position are fine, at least they should cite some of the primary literature.

Thanks Bugsy for pointing out some statistical understandings that many people do not quite understand. In my field of medical research I like to point out that if you require statistics to show any differences between groups then the effect must be very small. Of course this does not really apply well to epidemiology, however if you treat people with a drug and they have a statistically significant improvement of 2%, then it is still not a good drug.

Gladfly/Edmund et al. Let me put it this way. You have previously agreed that alcohol increases the risk of breast cancer. This is supported by the primary literature, as well as by the American Institute for Cancer Research, the NCI, American Cancer Society etc. However I can cite many studies such as:
http://www.sciencedirect.com/science/article/pii/S1047279708000288
that disagree with the current guidelines regarding alcohol consumption. Does this mean that all of the other researchers are conspiring to censor this information? Is there a conservative/progressive/greens/feminist plot in the works to deny us our right to have a drink? Should we be recommending that women now consume alcohol? Of course not. What we do is to gather a large number of experts in the relevant fields and reach a consensus agreement on what recommendations should be given to women based on all the information available. This is then revised at multiple points in the future as new information is available

To directly answer Gladflys question:
"“There are so many other messages we can give women about lifestyle modification and the impact of lifestyle and risk that I would never be a proponent of going around and telling them that having babies is the way to reduce your risk.” Does that sound like an objective, scientific position to you?"

Yes that does sound like an objective scientific position to me, and based on my reading of the literature over the last few days I agree with the statement. Complete mastectomy also significantly reduces the risk of breast cancer, but it seems a bit extreme to recommend this to women does it not?

However like with many other abortion-related issues, breast-cancer is not the primary concern for you is it. Obesity, diet, alcohol, genetics, etc. all have a much more important impact on breast cancer risk. Take abortion out of the picture, and you don't really seem to care about breast cancer anymore.

Bugsy asked for proof that oestrogen is linked with breast cancer risk. Try googling - you'll get nearly 270,000 hits! Those I checked strongly confirmed the link, including a study by Travis and Key (Breast Cancer Res, 2003) titled "Oestrogen exposure and breast cancer risk". The authors set out to explore this hypothesis, and concluded: "Oestrogens have a key role in the aetiology of breast cancer, probably because of their proliferative effects."

You can also google "oestrogen increase during pregnancy" - you'll get over 3 million hits on that one!

It amazes me that some people accept that being fat is a breast cancer risk because fat cells secrete oestrogen, but refuse to consider that high levels of oestrogen during pregnancy, before protective breast changes take place in the last trimester, might be a similar or greater risk.

There is, sadly, a simple reason - politics. Bangladesh is one example. It is a very poor country, but is now richly endowed with reproductive health clinics in city and rural areas, courtesy the UN and generous donations by Bill and Melinda Gates, who are determined to stamp out poverty by preventing over-population. Hormonal contraception and abortions are provided free of charge, and late abortions for sex-selection are common. The only Bangladeshi ABC study so far has found a huge ABC risk.

It is not hard to imagine why official recognition of the ABC risk might be considered contrary to the best interests of population controllers.

Edmund Burke, I did not ask for proof of the 'link' between oestrogen and breast cancer risk, rather some sort of literature that you have read that shows where you got your information from that it was a 'cause' of cancer. I can use google to find literature that states that there is a link also. What I cannot find is the 'smoking gun', as it were. The papers that show that actually causes breast cancer.

You state it so positively as if it were 'just so', and yet when I do search the literature I get conflicting conclusions.

One good review I dug up was http://www.ncbi.nlm.nih.gov/pubmed/22646135 (abstract only unfortunately)

Chains of evidence, mosaics of data: does estrogen 'cause' breast cancer? How would we know? (2012) Bluming AZ, Tavris C. Climacteric. 2012 Dec;15(6):531-7. doi: 10.3109/13697137.2012.678915

It discusses the lack of coherence of the estrogen-breast cancer story quite clearly.

I just cannot understand your tone of certainty.

(BTW, I wouldn't be pinning my colours to that 'Bangladesh study just yet, it has some major problems, including showing that higher education levels and personal income were also considered 'risk factors').

Stezza

At the end of the day it comes down to whether or not abortion raises the breast cancer risk. I don't know and nobody knows at this stage but what can be said is that the risk is sufficiently well documented for women to be warned of it prior to the abortion. They can choose to take the risk or avoid it. That is up to them. This discussion is not about the morality or legality of abortion. It is about the potential risk of breast cancer from abortion.