Another breastfeeding/breast cancer study!

[sntm]

Argh, my original post disappeared! Oh well...

Hope y'all aren't getting tired of these but I've finally found my calling, so...

Big multicenter case control study of reproductive factors and breast cancer. About 4000 women in each group (breast cancer or no breast cancer).

After controlling for pregnancy (so in addition to the positive effects of pregnancy), every 12 months over a woman's life that she breastfed reduced her risk of breast cancer by 5%. The effect was greatest in the first 5 years after breastfeeding, but some effect persisted over the woman's life. There was an effect even with as little as < 1 month of breastfeeding. The effect was the same in white and black women, though black women were less likely to breastfeed and breastfed for shorter durations.

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shannon
not-even-pregnant-yet-overachiever
trying-to-conceive :)
PREGNANT! EDD 6/9/03
mama to Jack 6/6/03
http://www.gynosaur.com/assets/ribbons/ribbon_emerald_18m.gif[/img][/url]
Breastfeeding 19 months and count

[caheinz]

Do you have the reference? (Too lazy to look it up, but willing to see if I can see it if you tell me where to look!)

Preferably the original study, not a news link....

Thanks!

[COElizabeth]

Shannon,

Thanks! What do you mean by the "positive effects of pregnancy"? Does pregnancy itself reduce a woman's risk of breast cancer? I'm just curious as I have never heard that before.

ETA: I guess I have heard of pregnancy reducing risk before, but I thought it was just pregnancy by a certain age, like 30? But I don't know much about it.

Elizabeth, Mom to James, 9-20-02
and Charlotte, 11-04-04

[egoldber]

Oops. Forget what I said before, its not accurate.

Here's a link that talks about the benefites of pregnancy:

http://cis.nci.nih.gov/fact/3_77.htm

But I am also atill confused about the benefits of pregnancy in reducing breast cancer risk.

[westchicagomom]

It is my understanding that the rush of estrogen produced by pregnancy appears to have breast cancer inducing-effects on mature breast cells which generally can be found in the breasts of women 30 and older.

And you are right - pregnancy before 30 apparently reduces the risk of breast cancer due to some effect of the estrogen on immature breast cells.

But I don't think this is set in stone. Coincidentally I have a handout in front of me that lists "Having a first child after age 30 or not ever having children" as one of the top 5 risk factors for breast cancer. But the doctor who gave me the handout said she didn't think having a baby after 30 was a risk factor (she was possibly just trying to calm my fears as I was 35 years old, only 6 weeks post partum and my younger sister had just been diagnosed w/ bc)

In any case, hopefully this study convinces more woman over the age of 30 to breastfeed for as long as possible if they are able to.

[sntm]

Yikes, not in front of me. It was in Cancer, volume 101 I think. I'll post on Monday.

The benefits of pregnancy are greater with first baby before age 30 and with multiple pregnancies (so moms of 5 are better protected than moms of one).
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
shannon
not-even-pregnant-yet-overachiever
trying-to-conceive :)
PREGNANT! EDD 6/9/03
mama to Jack 6/6/03
http://www.gynosaur.com/assets/ribbons/ribbon_emerald_18m.gif[/img][/url]
Breastfeeding 19 months and count