Young girls may hold key to breast cancer

What if you could do something to save your daughter from ever developing breast cancer?

Would you insist on breastfeeding her as an infant? Never use plastic while

What if you could do something to save your daughter from ever developing breast cancer?

Would you insist on breastfeeding her as an infant? Never use plastic while microwaving her food? Guide her to an active lifestyle, with exercise each day? Prepare low-fat meals from scratch? Make sure the school did, too? Buy organic?

We've all heard of changes in diet and lifestyle to prevent cancer in adults. But it looks more and more as if a cancer-free adulthood is determined years earlier -- maybe even before birth.

If my own experience raising kids is a guide, these things are easier said than done. But having recently come through cancer treatment myself, I'd want to do anything I could to prevent my children from ever having a doctor tell them they have cancer. First, however, I'd like to know which recommendations are supported by scientific evidence.

Answers may be coming.

Scientists now are focusing on childhood development and environmental influences as factors in certain cancers. One of the hottest topics: the declining age of sexual maturity in girls and its links to breast cancer.

Girls who have their first period before age 11 are at triple the risk for breast cancer, compared to those who have it after. Those who have it before age 12 are at double the risk.

The link between early puberty and breast cancer is estrogen. The greater the lifelong exposure to estrogen, the greater the risk of breast cancer. The years between a girl's first period and her first pregnancy -- when her breast cells have not differentiated and are multiplying rapidly -- appear to be a time of particular vulnerability to mutation or environmental damage.

The audience always gasps when Elisa Bandera, an epidemiologist at The Cancer Institute of New Jersey, presents those facts.

Bandera's "Jersey Girls Study" is one of a few around the country -- and the only one in New Jersey -- trying to tease out the environmental, hormonal and nutritional factors involved in causing early puberty.

"I want to go beyond breast-cancer prevention and help these girls," Bandera says. "I want to understand what causes early puberty -- not just menarche [the arrival of the first period], but breast development and pubic hair growth. We're looking at diet and physical activity, collecting body measurements, asking about environmental exposures, even prenatally and in early childhood."

She's especially interested in diet and whether eating organic food can delay the onset of puberty.

A girl's genes set the tempo of puberty's arrival -- her timing will be similar to her mother's, for the most part. But the variation from one generation to the next is more than half determined by environmental influences, experts say.

The arrival of a girl's first period is the last step in a series of changes that generally unfolds over a 4½-year period, beginning with the production of new hormones and usually proceeding to breast development, growth of pubic and underarm hair and menstruation.

Today's mothers know that their daughters and daughters' friends develop sexually at younger ages than the mothers did. Ilise Zimmerman, a women's health agency executive from Haworth who also coaches girls' basketball, says she's amazed each year at the voluptuousness of her 12-year-old players. "We see it when we order T-shirts," she says. "There are no size 'smalls.' "

While the age at first menstrual period has declined slightly over the last two decades, the onset of the other signs of puberty is dropping faster, and appears to be influenced in part by different factors.

"They moved up that little talk they do for the girls now to fourth grade," says Monica Dottino, a Mercer County mother of four whose 10-year-old daughter is part of the study. "A lot of parents don't want to talk about it."

Puberty at age 6

As early as the third grade, nearly half of African-American girls and 15 percent of white girls begin breast development or pubic-hair growth. The average age to begin breast development, according to a landmark 1997 study, is 8 years and 9 months for African-American girls and around the 10th birthday for white girls. The cause of the racial difference is not known.

So many girls now begin puberty at younger ages that the Pediatric Endocrine Society officially lowered the definition of precocious puberty, from 8 years old to 6 for African-American girls and 7 for white girls.

The Jersey Girls Study -- which is to include approximately 150 9- and 10-year-olds -- asks whether the girl was fed breast milk, milk formula or soy as an infant; whether she sucked on a pacifier; and what her birth weight and growth rate were, among other questions. The girl's physician and mother report periodically on her physical maturation. The girls are asked to spit in a cup so their DNA can be extracted from the saliva. Their urine is tested for chemical compounds and hormones. Their food consumption for three days in a two-week period is analyzed.

"It makes you realize how many things go on in a day that affect a child's health," says Dottino, the Mercer County mom. "We had to track hair products, shampoos, perfumes, everything she ate."

Dottino's own mother had breast cancer 15 years ago, so she values the study's potential contribution to breast-cancer prevention. "It was pretty interesting to track everything," she said. "You look at all the crap these kids eat."

Michele King of Lawrenceville, the mother of five girls ages 2 to 13, has two daughters in the study. She says that "using organic dairy products has always been part of what we did, but five years ago, we expanded to more natural products throughout our diet." The girls complained a bit, especially about the whole-grain cookies.

The study showed the girls that "it's not just Mom and Dad who think about this," King says. "Other people do, too. There must be something to it."

She adds: "I'll be curious to see where this all goes."

Early puberty has other downsides besides the future risk of breast cancer. It's associated with more risky behaviors, such as smoking, drinking and unprotected sex, and depression and anxiety. That is not to say, of course, that all girls with early periods turn out that way, but the risk is greater.

"We have to have the conversation earlier" about the consequences of early sexual activity, says Zimmerman, chief executive of the Northern New Jersey Maternal-Child Health Consortium and the mother of two daughters.

Obesity a factor

Scientists are concentrating on two broad factors associated with puberty's early onset: obesity and hormonally active chemicals in the environment.

"Girls who are heavier go into puberty earlier," says Dr. Frank Biro, a pediatrician and the principal investigator in a study of 400 girls at the University of Cincinnati College of Medicine. American girls eat more than they did 30 years ago and exercise less. Childhood obesity is three times as common. Fat is related to hormone levels.

Not only does "over-nutrition" contribute to earlier onset of puberty, but exercise -- by upping the production of certain hormones and taking weight off -- delays it.

At the same time, girls today live in a world with microwave ovens, computers, and fertilized and bio-engineered lawns and crops.

"We've become a plastic nation -- a plastic nation that super-sizes everything," Biro says. "It's the chemicals we're all exposed to by putting plastics in microwaves, using cleaning agents around the house and spreading lawn-care products on the grass" that, in combination, can mess with hormone levels.

Research in 2002 found that the combination of 11 different chemicals people are exposed to in everyday life, each present below the level known to cause any observable effect, produced a cumulative effect. When all were present together, "Poof! There was an estrogenic effect," Biro says. "I find that incredibly sobering."

Phthalates, the substances that make plastic soft and pliable, are used in food packaging, IV tubing and personal-care products. They've been found in breast milk and in the urine of average Americans, and are the subject of intensive study about their possible role in cancer, early puberty in girls, low sperm counts and male reproductive disorders.

California became the first state to ban phthalates in toys and baby products in October. The European Parliament also banned some forms of plasticizers and restricted others in children's items in 2005. Canada has had voluntary restrictions in place since 1998. Not New Jersey.

"We shouldn't be nuking anything that isn't in glass or porcelain in our microwaves," says Biro, ruefully describing his own past history of reheating Saran-wrapped leftovers. "I was dosing myself with phthalates." Microwaving can cause phthalates to leach into food, according to a fact sheet prepared by the federally funded Breast Cancer and the Environment Research Center at the University of Cincinnati.

Common-sense steps

What else should a parent do? For the most part, the recommendations about preventing early puberty, at least so far, are common-sense approaches to good health.

Help your kids maintain a healthy weight. Encourage physical activity. Eat plenty of fruits and vegetables.

When I asked Bandera, the mother of a 10-year-old daughter and a 14-year-old son, how she combined her role as a scientist and a mother in raising her kids, she said there's no need to overdo it.

She buys healthy food, including whole grains, organic milk, and plenty of fruits and vegetables, and tries to cook from scratch. She tries to keep her kids active. And she models the healthy choices she'd like them to make: She doesn't smoke or drink; she controls her weight and stays active.

"They're going to be exposed to other things sooner or later," she says, "but they will know what the good choice is. That's all you can do. Then you hope for the best."

I have two sons and no daughters. But I think this is sound advice for all of us, if we want to spare our children the suffering of cancer.

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Participants still being sought

The Jersey Girls Study is still recruiting participants.

Healthy 9- and 10-year-old girls who live with their biological mothers are eligible. Girls who are twins, triplets or other multiples, or who have certain chronic health conditions, are not eligible.

The girls will receive a free analysis of their dietary intake, body measurements (including percent body fat), a $25 gift card and some cute knickknacks.

The study is a collaboration of The Cancer Institute of New Jersey, the Robert Wood Johnson Medical School, UMDNJ's School of Public Health, and the Environmental and Occupational Health Sciences Institute.

If the number of potential participants from northern New Jersey warrants, says Dr. Elisa Bandera, the principal investigator, the research team will arrange with a local hospital or pediatrician's office to assess the girls on a single evening, or a series of evenings.

For further information, call 732-235-9860 or e-mail This e-mail address is being protected from spam bots, you need JavaScript enabled to view it

-- Lindy Washburn

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