Subscribe to the BioNews newsletter for free

Login
Advanced Search

Search for
BioNews

Like the Progress Educational Trust on Facebook


The Fertility Show


 

Fertility drugs may not increase breast cancer risk

07 April 2014

By Dr Lux Fatimathas

Appeared in BioNews 749

Fertility drugs used to stimulate ovulation did not increase the chances of breast cancer for most women in a long-term study of around 10,000 women in the USA.

However, an elevated risk was noted in women who were treated with high doses that are no longer recommended and a subset of women who did not become pregnant after treatment.

As previous studies have produced mixed results on the effect of fertility treatment on breast cancer risk, lead study author Dr Louise Brinton of the National Cancer Institute, USA, said her team set out to look at any long-term effect 'after controlling for other factors that have been shown to be correlated with both breast cancer risk and use of those drugs'.

She added: 'Overall, our data show that use of fertility drugs does not increase breast cancer risk in this population of women, which is reassuring'.

The study looked at women who were evaluated or treated at five clinics in the USA between 1965 and 1988. Just under half received fertility treatment with clomifene citrate and/or gonadotrophins. All patients were followed up over the course of 30 years and breast cancer rates were compared between groups. The researchers took into account confounding factors like a family history of breast cancer.

Most women who received clomifene citrate did not show an increased risk of breast cancer compared with women not given fertility drugs. However, those who received 12 or more cycles of this drug were one-and-a-half times more likely to develop invasive breast cancer.

Breast cancer risk was also doubled in women who failed to become pregnant following treatment with both clomifene citrate and gonadotrophins. This finding counters that from a separate, smaller study published two years ago, which found a reduced breast cancer risk for women given fertility drugs who did not become pregnant (see BioNews 666).

Dr Brinton remarked: 'The observed increase in risk for these small subsets of women may be related to persistent infertility rather than an effect of the medications. Nevertheless, these findings stress the importance of continued monitoring of women who are exposed to fertility drugs'.

Current recommendations in the USA suggest clomifene citrate should be prescribed for a maximum of three to six cycles, with doses of up to 100mg. But when the patients in this study received their treatment the guideline doses were higher, with several women receiving doses of up to 250mg for several years.

Although the increases in breast cancer risk in this population were relatively modest, those who went on to develop breast cancer did so at an average age of 53 years, younger than that seen in the general population.

As well as suggesting that this group of women should continue to be monitored, the authors say that further work is needed to investigate the effect of current fertility drug regimes on breast cancer risk.

The study was published in the journal Cancer Epidemiology, Biomarkers and Prevention.

SOURCES & REFERENCES
CBS News | 04 April 2014
 
Reuters | 03 April 2014
 
Cancer Epidemiology, Biomarkers and Prevention | 03 April 2014
 
EurekAlert! (press release) | 03 April 2014
 
Cancer Network | 03 April 2014
 

RELATED ARTICLES FROM THE BIONEWS ARCHIVE

30 June 2014 - by Dr Nicoletta Charolidi 
A simple blood test that can predict the likelihood of developing non-inherited breast cancer could be developed, following research into the epigenetics of the disease...
12 May 2014 - by Dr James Heather 
Doctors, survivors and supporters again converged in a basement lecture theatre in Bloomsbury for the second event in PET's 'Breast Cancer' series. On the cards this night: prediction and screening...

23 July 2012 - by Victoria Kay 
Women who undergo fertility treatment but do not become pregnant have a reduced risk of developing breast cancer before the age of 50, according to scientists...
21 May 2012 - by Dr Greg Ball 
A senior IVF doctor has voiced concerns over health risks to women in IVF treatments that are commonly practiced by UK clinics...
31 October 2011 - by Sarah Pritchard 
Women who undergo IVF treatment have an increased risk of developing borderline, non-fatal ovarian tumours according to a clinical study from the Netherlands...
09 February 2009 - by Katy Sinclair 
Researchers at the Danish Cancer Society have ascertained that taking fertility drugs does not increase a woman's chance of developing ovarian cancer. The results of the study are published in the British Medical Journal. Allan Jensen and colleagues studied 54,362 women referred to fertility clinics between 1963...

HAVE YOUR SAY
Be the first to have your say.

You need to or  to add comments.

By posting a comment you agree to abide by the BioNews terms and conditions


- click here to enquire about using this story.

Published by the Progress Educational Trust

CROSSING FRONTIERS

Moving the Boundaries of Human Reproduction

Public Conference
London
8 December 2017

Speakers include

Professor Azim Surani

Professor Magdalena Zernicka-Goetz

Professor Robin Lovell-Badge

Sally Cheshire

Professor Guido Pennings

Katherine Littler

Professor Allan Pacey

Dr Sue Avery

Professor Richard Anderson

Dr Elizabeth Garner

Dr Jacques Cohen

Dr Anna Smajdor

Dr Andy Greenfield

Vivienne Parry

Dr Helen O'Neill

Dr César Palacios-González

Philippa Taylor

Fiona Fox

Sarah Norcross


BOOK HERE

Good Fundraising Code

Become a Friend of PET HERE and give the Progress Educational Trust a regular donation