Study Confirms Link Between Pill, Breast Cancer

By Mike Wendling | July 7, 2008 | 8:11 PM EDT

London ( - Women who take the contraceptive pill face an increased risk of breast cancer, according to one of the largest studies yet on the links between lifestyle and cancer.

The report, released over the weekend at the 3rd European Breast Cancer Conference in Barcelona, Spain, found that of the more than 100,000 women studied, those who used the pill at any point during their lives increased their chances of developing breast cancer by 26 percent.

Longer-term use of the pill increased the risk further, to more than 50 percent above the level of those who never used the pill.

The highest danger was for those over age 45 still using the pill. Women in that group faced a risk more than one-and-a-half times the danger for those who never used the pill.

Researchers interviewed the women ten years ago and followed them through to December 1999, finding that in that time more than 1,000 cases of breast cancer were detected in the sample group.

The leader of the study, Norwegian epidemiologist Dr. Mereth Kumle, said that her research supports previous studies into the connection between the pill and female health.

"It is clear that oral contraceptives increase a woman's risk of developing breast cancer, particularly when they are used in the later period of reproductive life," Kumle said.

Her researchers found similar risk increases compared to previous inquiries, but studies also indicate that the breast cancer risk is gradually reduced if women discontinue using the pill at or before menopause. Kumle told the conference that the overall danger to women was relatively small.

"It is important to remember that the absolute risk of a woman developing breast cancer under the age of 40 is very low. Modern oral contraceptives have much lower hormone doses in them than the older ones which did cause an unacceptably high number of adverse effects," she said. "As contraception, the pill should still be the drug of choice for young women."

But pro-life groups challenged the doctor's conclusion. A spokeswoman for U.K.-based Life called the study "highly significant."

"This is in direct conflict with the assurances of British scientists that chemical contraception is not dangerous," spokeswoman Rachel Heath said Monday.

"As recently as September 2000, the Imperial Cancer Research Unit categorically stated that the pill carries 'only a small increased risk of breast cancer' and the Royal College of Obstetricians and Gynaecologists (RCOG) has endorsed their words. Somebody is not telling the truth," Heath said.

Life commissioned research last December that indicated a link between abortion and breast cancer. The study found that if current trends continue, the incidence of breast cancer in England could rise by up to 60 percent within 25 years.

An analysis by the independent Pension and Population Research Institute found that the increase is mostly due to a higher abortion rate, although the RCOG insists increased detection and delayed childbirth are to blame.

At the weekend conference, Kumle asserted that there were several factors behind the rise in breast cancer rates.

"The incidence of breast cancer in Western countries has been increasing in the past 30 years, but there appears to be a number of reasons for this," she said. "The use of oral contraceptives is one reason, but girls tending to start their periods earlier, women having fewer and later births, later menopause and (obesity) after menopause are all reasons too."

Heath said that the hormonal changes in a woman's body caused by an abortion were similar to those caused by the pill - but much greater.

"Induced abortion must be more dangerous than pill-taking," she said. "It is only now after 40 years of the pill that we are recognising the implications for women's health. When will the medical establishment accept the link between induced abortion and breast cancer? Women cannot afford to wait another 40 years."

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