Issue 36 / 29 September 2014

NEW Australian research has again ruled out any link between abortion and breast cancer, after experts were prompted to review local data in response to suggestions in the media that such a link may exist.

In a research letter published by the MJA, Victorian cancer researchers detailed a prospective cohort study in which they found no association between abortion in the first trimester and breast cancer. (1)
Similarly, no breast cancer link was found with abortion before first full-time pregnancy or with abortion in the first two trimesters.

The researchers reviewed the records of 24 018 Victorian women, aged 40‒69 years who were free of cancer when their data were collected between 1990 and 1994 as part of the Melbourne Collaborative Cohort Study. (2)

These records, which included information on all pregnancies but did not differentiate between spontaneous and induced abortion, were reviewed against the Victorian Cancer Registry. The researchers found that up to December 2012, 1235 of the women were subsequently diagnosed with breast cancer.

The findings came after media reports that senior federal government minister, Senator Eric Abetz, had suggested on a commercial news program that there was a link between abortion and breast cancer, sparking condemnation by medical experts. Senator Abetz later denied making such a claim. (3)

Professor Kelly-Anne Phillips, a coauthor of the MJA research letter and head of the Breast and Ovarian Cancer Risk Management Clinic at the Peter MacCallum Cancer Centre, said the recent controversy was surprising, particularly given that such a link had been ruled out by an analysis of data from 53 studies a decade ago. (4)

“We, along with many national and international organisations, including Cancer Australia, had been very clear that there is no link, based on the previous, pretty vast literature that was out there”, Professor Phillips told MJA InSight.

However, she said that until now the only Australian data available was a case–control study from the 1980s which purported to show a link between breast cancer and abortion. She said there was good literature demonstrating that reporting bias was present in case–control studies of this issue, so they tended to erroneously show a link.

“We decided it was important to look at this question prospectively in an Australian cohort”, she said.

“It’s a prospective study, it’s much more robust and, as with the other prospective studies internationally, we did not show a link between abortion and breast cancer. That’s clear.”

Associate Professor Stephen Robson, vice-president of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG), said the idea that termination of pregnancy (TOP) might cause breast cancer had been suggested as a hypothesis about 35 years ago, based on small-scale animal experiments.

“However, thorough and extensive analysis of data in the subsequent years has not unearthed any causative link between TOP and breast cancer. Any correlation between the two is likely to represent a bias due to recall — women who have breast cancer are more likely to think about events in the past and are more likely to tell investigators about a previous TOP than women who do not have breast cancer”, he said.

“RANZCOG, like virtually every women’s health body around the world, does not support any link between TOP and subsequent breast cancer.”

Cancer Australia also confirmed that the research on this issue is clear. “Research has shown there is no link between termination of pregnancy and increased risk of breast cancer. This includes both induced abortion and spontaneous miscarriage”, a Cancer Australia spokesperson said.

Ms Katie Clift, a spokesperson for Cancer Council Queensland, told MJA InSight: “This local research is important, and reinforces the latest evidence, which should well and truly put this issue to rest.”


1. MJA 2014; Online 29 September
2. Cancer Council Victoria: Overview of Melbourne Collaborative Cohort Study
3. Senator Eric Abetz: Statement regarding incorrect reports, 8 August 2014
4. Lancet 2004; 363: 1007-1016 http

(Photo: bikeriderlondon / Shutterstock)

4 thoughts on “Cancer–abortion link quashed

  1. Dr William Warr says:

    What about looking at the worrk of Dr Joel Brind from Penn State Medical School in 1996 and published in the BMJ

    What about the recently released 36 Chinese studies showing a 44% increase in the incidence  

    What about the 12 recently released studies from India- 30% increase in incidence

    Not to forget the work of  Dr  angel Lanfranchi  which caused all the furore in Australia recently

    It’s Ok for all and sundry to push the “Abortion OK ” wheelbarrow, but when anyone gives the contrary view it is behaving “irresponsibly” according to the AMA president

  2. Sue Ieraci says:

    Considering the high rate of spontaneous miscarriage (10% and possibly up to 20% of very early pegnancies), it has never seemed plausible that induced abortion would have any independent impact, even if there were a link with breast cancer. Now that medical termination of pregnancy is available, there is very little difference between spontaneous and induced abortion. If anti-abortionists were honest in their concern for women developing breast cancer, wouldn’t they also work to minimise spontaneous miscarriage? One has every right to hold moral views about induced abortion, but not to create false arguments about medical complications.

  3. Genevieve Freer says:

    While there have been suggestions regarding what may be protective against breast cancer, there also are suggestions regarding  what may increase the risk. Regardless , breast screening is offered to all women

    I am not sure why those claiming that termination of pregnancy causes breast cancer do so-do they  they hope to make those women unfortunate enough to have had both breast cancer, and to  have had a termination of pregnancy feel guilty?

    Do they imagine that fear of breast cancer will stop women from having a termination of pregnancy? If so, that fear would need to be greater than the fear of the person/s demanding that the woman have a termination, whether these persons are the woman’s partner, family, friends, employer,or government..

    I doubt that fear of what may happen in many years to come will override fear of will happen in the shorter-term.


  4. Joel Brind says:

    Why does MJA InSight claim new a Victorian study by Phillips, et al. “has ruled out any link between abortion and breast cancer”, when the opposite is true? Phillips et. al found no significant link, but did not distinguish between induced abortions and miscarriages. Miscarriages are known not to be linked to breast cancer, so studies that don’t distinguish the two necessarily underestimate the risk. Nevertheless, Phillips et al. reported a 7% increase in risk among women with any abortions or miscarriages. Though not achieving statistical significance, this finding is hardly describable as “ruling out” a link. But there’s more. The Phillips study–published, as it was, though the “back door” as a mere letter–showed only selected data, such as a non-significant 3% decrease in risk for “abortion before first full-term pregnancy” (mostly miscarriages), but not the other side of that statistic, i.e., (mostly induced) abortion after first full-term pregnancy. That statistic was (quite improperly) not shown. Could it be because it was perhaps a statistically significant 15-20% risk increase? And while we’re on the subject (of covering up an abortion-breast cancer link), no one has ever explained why the 160% risk increase for nduced abortion found among South Australian women by Rohan et al., was omitted from their 1988 paper, this strong and signficant risk incease only showing up 7 years later in another journal. And why is the MJA not concerned about the 13 studies in the last 6 years along from South Asia, all reporting increased risk, by as much as 2,000%?

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