102794 Women who have abortions may increase their risk of breast cancer

WASHINGTON - Women who have abortions may increase their risk of breast cancer by 50 percent, according to a new study in the Journal of the National Cancer Institute. Experts say the conclusion needs more study.

Researchers at the Fred Hutchinson Cancer Center in Seattle based their conclusion on an analysis of interviews with 845 breast cancer patients and 961 healthy women of the same age group.

The scientists, led by Janet R. Daling, compared answers to questions about the women's reproductive histories and concluded that there was a statistical suggestion that those who had induced abortions were more likely to have breast cancer.

"Highest risks were observed when the abortion was done at ages younger than 18 years - particularly if it took place after eight weeks gestation - or at 30 years of age or older," the study said.

The risk was not affected by the number of abortions or by other reproductive experiences, such as live births or miscarriages, the study said.

Dr. Noel S. Weiss, a co-author of the study, said in an interview that it would be "premature" for women to make any abortion decision now, based on the study.

"They (women) should not give this study any weight in a making a decision now," said Weiss. "But the findings are provocative. If they are replicated (by other researchers), then the conclusions should be considered by women."

Lynn Rosenberg, of the Boston University School of Medicine, who reviewed the study, said the results are "very preliminary and have not been confirmed."

"There is a body of evidence that comes before this that largely shows no association between abortion and the risk of breast cancer," she said.

Rosenberg also said the 50 percent increased risk found by the study is actually a "very small added risk."

Weiss concurred. He said that the annual risk of breast cancer for a 40-year-old woman is 0.4 per 1,000. A 50 percent increase would raise this risk to 0.6 per 1,000.

The National Alliance of Breast Cancer Organizations also advised that the study results should be "interpreted with caution."

In their report, the researchers acknowledged a possibility of bias in the study because women in the survey could inaccurately report their reproductive histories.

All of the women interviewed in the study were born after 1944, which means some or most of the women's reproductive experience was in an era of legal abortions. The U.S. Supreme Court legalized induced abortions in 1973.