Thursday, September 23, 2010

The Pill-Breast Cancer Connection. Does it exist?

If so, it's a very small risk

Last summer, in a study of more than 50,000 African-American women, Boston University epidemiologist Lynn Rosenberg found a 65 percent increase in a particularly aggressive form of breast cancer among those who had ever taken the birth-control pill. The risk doubles for those who had used the contraceptive within the past five years and had taken it for longer than 10 years.

A commemorative piece flatly asserted earlier this year that "taking the pill has no impact on breast cancer risk."

Rosenberg's findings question that assertion. She wanted to study black women because they have been underrepresented in cancer research so far, even though they suffer from higher rates of "triple negative" breast cancer. This relatively rare form of breast cancer, in which the tumors lack certain genes and so are not responsive to standard treatments like tamoxifen, confers the highest and fastest mortality. In Rosenberg's work, it was these cancers that were linked to the pill. A number of other studies of women of multiple races support her data implicating the pill in breast cancer, including research done in New England; South Carolina; Long Island, N.Y.; and Scandinavia.

At the same time, other large studies, including one published in the New England Journal of Medicine in 2002, found no increase in breast-cancer risk among pill users. Further complicating the health-risk equation, it's already well-established that the pill offers some protection to women from ovarian and endometrial cancers. One recent study of 46,000 women over the age of 40 by the Royal College of General Practitioners found that, despite a small increased risk of breast cancer in women under 45, pill-users as a whole actually live longer than other women. But this becomes less surprising when you figure that women who pop the pill tend to be healthier to begin with (for one thing, they have to see a doctor regularly in order to get a prescription).

So what are we to make of the breast-cancer connection? If it exists, why aren't the studies consistent? For one thing, Rosenberg explains that the association she found is relatively small. Compare the 65 percent increase in risk with the 2,000 percent increase in risk of lung cancer linked to smoking. Patterns are hard to spot because even when researchers use a large sample size, only a much smaller number of people will get cancer. (Even the smoking-lung cancer connection took decades of epidemiological head-scratching to figure out.) And if the pill is mostly causing the rare triple-negative type of breast cancer, the effect could be muddied in a study looking at breast-cancer disease overall.


An Australian female Hitler calls for infant formula to be made hard to get

Infant formula should be available only on prescription to boost breast feeding rates, an expert says. But Victoria's peak doctors' group and Melbourne mothers say the proposal goes too far.

Jennifer James, of RMIT University, said formula manufacturers should also be banned from marketing their products to the public.

"When women are having problems, and it's very challenging learning to breast feed, the formula is readily available and the marketing suggests that babies will thrive on it, so women go for it," Dr James said.

"The majority of women and new dads that you speak to will give you some reasons why it's important to breast feed but there's still this pervasive belief that 'I'll try it and if I can't do it, formula's just as good'. "I would like to see formula prescribed by a health professional rather than being available in supermarkets and chemists."

Melbourne mum Christine Rookas said it should be a mother's choice whether to breast feed or not. "I would be very frightened and afraid to think that formula will be prescribed," Ms Rookas, from Avondale Heights, said. "I think there's already a paranoia for mothers. They feel guilty enough about using formula milk."

Ms Rookas was still breast feeding six-month-old Neave, as she had her two older children, despite finding it tough. "I just kept persisting ... because it's more convenient rather than a huge health benefit," she said.

AMA Victoria president Harry Hemley said requiring a prescription for infant formula would be very inconvenient for new mothers. "There's no doubt that new mothers need more support to make sure their children are as fit and healthy as possible," Dr Hemley said. "Breast feeding is the best option for most new mothers, but not for everyone."


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