Prognosis: Predicting Cancer Risk in the Long-Term

[Guest guest]

Prognosis: Predicting Cancer Risk in the Long-Term

http://www.aacr.org/home/about-us/news.aspx?d=739

April 16, 2007

LOS ANGELES - Every day, people make assumptions, educated and not, about

their risk for developing cancer. For many, the risk of developing a secondary

cancer after an earlier illness rests uncomfortably in the backs of their minds.

Researchers are continuing to understand the factors that might dictate an

individual's risk of developing primary or secondary cancer. The risk of

developing cancer depends on the subtle interplay of genetics, personal choice

and

the environment, according to several long-term studies presented today at the

2007 Annual Meeting of the American Association for Cancer Research.

Parity, Breastfeeding, and Breast Cancer Risk by Hormone Receptor Status in

Women with Late Age at First Birth-A Case-Control Study: Abstract 2610

Research has shown there is a connection between reproductive factors-such as

age at first birth, number of births, and breastfeeding-and a woman's risk of

breast cancer. Yet to be established is how these factors interact, and

whether they have differing effects on risk for breast cancers that are estrogen

and progesterone receptor positive (ERPR-positive) versus those that are not

(ERPR-negative).

A new study by a team of researchers in the U.S. and Australia suggests that

breastfeeding may help protect women against both subtypes.

" Our previous research had shown differing effects of these reproductive

factors on ERPR-positive and ERPR-negative breast cancers, and we wanted to

understand them better, " said study co-author Giske Ursin, M.D., Ph.D.,

associate

professor in the Department of Preventive Medicine at the University of Southern

California's Keck School of Medicine. " Our most important finding here is

that breastfeeding seems to modify the increased risk that comes from having

children later in life. "

The study looked at 995 women with invasive breast cancer (729 ERPR-positive,

267 ERPR-negative), and 1498 controls, aged 55 years or older who

participated in the Women's Contraceptive and Reproductive Experiences Study, a

multicenter study of breast cancer in white and African-American women. The

researchers

considered women's age at first birth, the number of births - referred to as

parity - and whether or not they had ever breastfed.

Women with a first birth before age 25 had 41 percent lower relative risk of

developing ERPR-positive breast cancer than women with no births; this

protective effect did not hold true for women who gave birth at or after 25. The

latter group also had double the risk of developing ERPR-negative cancers. " What

we find is that early age at first birth protects against ERPR-positive cancer,

but not receptor-negative, " Ursin said.

More notable, researchers said, was their finding related to age at first

birth and parity. Breastfeeding was protective for both subtypes, regardless of

when a woman gave birth.

" The protective effect of parity on ERPR-positive cancers was seen only among

women who breastfed, but not among those who never breastfed, " said Ursin.

" And for women giving birth after age 25, parity was associated with increased

risk for both types of breast cancer only in women who had never breastfed. "

The researchers concluded that breastfeeding may lessen the increased risk

that comes from having children later in life. According to Ursin, breastfeeding

may act through different hormonal mechanisms than early age at first birth

and parity.

For now, the study suggests that women who delay childbearing should consider

breastfeeding when they do have children. " We suspect that women can reduce

the increased risk that comes with later childbearing by choosing to

breastfeed, " Ursin said.

+++++++++++++++++++++

RISK REDUCTION STRATEGIES FOR BREAST CANCER -Tuesday, May 15th at 6 p.m.

Northern Dutchess Hospital, Woman's View Downstairs Conference Room,

Rhinebeck.

Learn how to create healthy, toxin-free environments. A discussion of the

Precautionary Principle and safe cosmetics and household products with Hope

Nemiroff, Executive Director of Breast Cancer Options.

FOR INFORMATION: 845-339-4673

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