LONDON - Having an abortion or miscarriage does not increase a women's risk of suffering from breast cancer later in life, scientists say.
In a finding that contradicts earlier research, a re-analysis of data from 53 studies in 16 countries involving women with breast cancer showed there was no link between the most common cancer in women and a terminated pregnancy.
"We can be really definitive that neither induced abortions nor miscarriages increase breast cancer risk," said Professor Valerie Beral, an author of the study from the University of Oxford.
She said results from previous studies that concluded there was a link were based on unreliable data and poor research.
"They mixed together studies that gave reliable and unreliable results," Professor Beral said.
The international collaboration, led by the Oxford team, analysed virtually all the worldwide data that looked at risk factors for breast cancer and concluded abortion and miscarriage were not associated with the disease.
"No one has ever done this before. We had the original data and could check it and analyse it in a similar way. No one had the ability to do that before," Professor Beral said.
The research included 44,000 breast cancer patients who took part in studies where a history of abortion had been recorded before the cancer was diagnosed.
The odds of developing the disease were compared in women with and without any record of abortion.
The findings, published in the Lancet medical journal, include results from previously published and unpublished research.
"This is the first time that so much information has been brought together and the findings are more reliable than ever before," says leading epidemiologist Sir Richard Doll, of the University of Oxford.
The scientists also reviewed data from studies in which 39,000 women were questioned about their history of abortion after they had been diagnosed with cancer, which was considered a less reliable format that could produce misleading results.
Their replies were compared with answers from women who did not have the disease.
The question of a link between abortion and cancer has been a heated topic in the abortion debate and has been seized on by anti-abortion advocates.
Despite doubts about the credibility of earlier studies, some researchers had suggested that women considering abortion should be warned about the raised risk of breast cancer.
- REUTERS
Herald Feature: Health
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No link between abortion and breast cancer, say scientists
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