different reproductive histories tied to risk of different bc subtypes
 

ABSTRACT: Reproductive history and risk of three breast cancer subtypes defined by three biomarkers
[Cancer Causes and Control]

Breast cancer subtypes defined by estrogen receptor (ER), progesterone receptor (PR), and HER2 expression are biologically distinct and thus, may have distinct etiologies. In particular, it is plausible that risk factors operating through hormonal mechanisms are differentially related to risk of such tumor subtypes. Using data from the Breast Cancer Surveillance Consortium, we explored associations between reproductive history and three breast cancer subtypes. Data on parity and age at first birth were collected from 743,623 women, 10,896 of whom were subsequently diagnosed with breast cancer. Cases were classified into three subtypes based on tumor maker expression: (1) ER positive (ER+, N = 8,203), (2) ER negative/PR negative/HER2 positive (ER-/PR-/HER2+, N = 288), or (3) ER-, PR-, and HER2-negative (triple-negative, N = 645). Associations with reproductive history, evaluated using Cox regression, differed significantly across tumor subtypes. Nulliparity was most strongly associated with risk of ER+ breast cancer [hazard ratio (HR) = 1.31, 95% confidence interval (CI): 1.23-1.39]; late age at first birth was most strongly associated with risk of ER-/PR-/HER2+ disease (HR = 1.83, 95% CI: 1.31-2.56). Neither parity nor age at first birth was associated with triple-negative breast cancer. In contrast to ER+ and ER-/PR-/HER2+ subtypes, reproductive history does not appear to be a risk factor for triple-negative breast cancer.

Re: different reproductive histories tied to risk of different bc subtypes
 

Yep! Applies to me. I was 33 years old when I had my first and only child.

Ellie

Re: different reproductive histories tied to risk of different bc subtypes
 

I was 31 when I had my first son.

Re: different reproductive histories tied to risk of different bc subtypes
 

I was 36 when my first child was born, but had ER/PR/HER+ pathology. Go figure!

But my growth was stopped at age 14 with large doses of hormones. So that may have increased my risk.

Jacqueline

Re: different reproductive histories tied to risk of different bc subtypes
 

Does not apply to me-

I was 18 when I had my first-
and I am

ER/PR- and HER2 +

Re: different reproductive histories tied to risk of different bc subtypes
 

I was 42 when I had my daughter, naturally pregnant, uneventful birth.
ER-/PR weakly positive (10%). HER2+++

Re: different reproductive histories tied to risk of different bc subtypes
 

I was 21 when I had my first child!

Re: different reproductive histories tied to risk of different bc subtypes
 

I had my son one week after my 24th birthday
ER+ Her2+ (? PR)

Re: different reproductive histories tied to risk of different bc subtypes
 

18 when I had my first child. ER+, PR+, Her2+.

Re: different reproductive histories tied to risk of different bc subtypes
 

30 and 33 when I had my children

Re: different reproductive histories tied to risk of different bc subtypes
 

27 and 30 when I had my children. Triple +.

Re: different reproductive histories tied to risk of different bc subtypes
 

Never had a pregnancy... speaks to my ER+ status at least.

Re: different reproductive histories tied to risk of different bc subtypes
 

I was 27, 30 and 32 when I had my children - Her2+, moderately ER+, PR negative.

Re: different reproductive histories tied to risk of different bc subtypes
 

3 infertility treatments at age 39 only resulted in three uterine fibroids. Started birth control pill to curb the growth of UF. 4 years later, I was diagnosed with BC with a 5% ER+ and Her2+++. First thing my doctor told me to do was to quit taking the birth control pills.

Re: different reproductive histories tied to risk of different bc subtypes
 

Just out of interest i have 3 friends who all had IVF in their late twenties/early thirties. They all now have ER+ bc! May be just coincidence??

Ellie

Re: different reproductive histories tied to risk of different bc subtypes
 

Highly triple pos and had my first child at 18!

Re: different reproductive histories tied to risk of different bc subtypes
 

Ellie,

A case-control study in 2008 concluded that it's not a coincidence:

Breast J. 2008 Nov-Dec;14(6):517-22. Epub 2008 Oct 14.
Beginning IVF treatments after age 30 increases the risk of breast cancer: results of a case-control study

http://www.ncbi.nlm.nih.gov/pubmed/19000041

Re: different reproductive histories tied to risk of different bc subtypes
 

Triple positive, children at 30 and 32.

Re: different reproductive histories tied to risk of different bc subtypes
 

"Cases were classified into three subtypes based on tumor maker expression: (1) ER positive (ER+, N = 8,203), (2) ER negative/PR negative/HER2 positive (ER-/PR-/HER2+, N = 288), or (3) ER-, PR-, and HER2-negative (triple-negative, N = 645)."
ER+ but no mention of HER2+ or am I reading this wrong?
I fit into 288 who are the er-/pr- and her2+++.
- first baby at age 30.

Re: different reproductive histories tied to risk of different bc subtypes
 

Fits me, too - 30 with the first, 33 with the second. Er-Pr-HER2+.