Nav: Home

Infertility is linked to small increased risk of cancer

March 12, 2019

A study of over 64,000 women of childbearing age in the USA has found that infertility is associated with a higher risk of developing cancer compared to a group of over three million women without fertility problems, although the absolute risk is very low at just 2%.

As cancer is unusual in pre-menopausal women, the researchers used a US database of health insurance claims in order to obtain large enough numbers to provide meaningful results. Many insurance companies in the US offer coverage for infertility testing and treatment. The research is published today (Wednesday) in Human Reproduction [1], one of the world's leading reproductive medicine journals.

Dr Gayathree Murugappan, a fellow in reproductive endocrinology and infertility at Stanford University School of Medicine (California, USA), who led the study, said: "We do not know the causes of the increase in cancer that we found in this study, whether it might be the infertility itself, the causes of the infertility, or the infertility treatment. We can only show there is an association between them. In the future, we hope that we will be able to understand why infertile women are at higher risk of cancer; for example, by identifying a common, underlying mechanism that can cause cancer and infertility."

Dr Murugappan and her colleagues analysed data from 64,345 women who had been identified as being infertile by diagnosis, testing or treatment in the Clinformatics® Data Mart database between 2003 and 2016. The database contained a geographically diverse group of patients, across 50 US states, although the majority of them were Caucasian. They compared them with 3,128,345 women who were not infertile and who were seeking routine gynaecological care. The women were in their 30s and the researchers followed their progress for an average of nearly four years.

During the follow-up period there were 1,310 cancers diagnosed among the infertile women and 53,116 among the control group of women who were not infertile. Breast cancer was the most common cancer in both groups. After taking into account factors that could affect the results such as smoking, obesity, age, education and reproductive age, they found that infertile women had an overall 18% higher risk of developing cancer compared to the control group, with absolute risks of 2% compared to 1.7%.

Senior author of the paper, Associate Professor Michael Eisenberg from Stanford University School of Medicine, said: "The low overall incidence of cancer among these women means that one in 49 infertile women would develop cancer during the follow-up period compared to one in 59 women in the women who were not infertile."

The researchers found that giving birth conferred some protection on women in both groups. Among the infertile women, 22,024 (34%) had at least one baby during the period studied, and 626,532 (20%) of women in the control group gave birth. The absolute risk of cancer was one in 56 infertile women and one in 86 women in the control group.

When the researchers excluded women who had polycystic ovary syndrome (PCOS) or endometriosis, which have been linked to an increased risk of uterine and ovarian cancers respectively, the absolute risk of cancer was one in 55 among the infertile women and one in 88 among the control group.

Looking at the risk of particular cancers, they found a slightly higher risk of hormone-driven cancers of the ovary and uterus among the infertile women, although the risk of breast cancer was similar between the two groups. They also found a slightly higher risk of cancers that were not driven by hormones among the infertile women, including lung, thyroid, liver and gallbladder cancers and leukaemia. "While several of these associations were significant, it is important to note that the absolute increases in risk were modest," said Dr Murugappan.

As the majority of cancers are diagnosed in older people, one of the limitations of the study is the age of the women, and also the short follow-up period. Other limitations include that women may have sought fertility treatment outside the US insurance system; some women might be infertile without knowing because they might have been using contraception, for instance; and the cause of infertility and the treatment given was not available from the insurance claims data.

Prof Eisenberg concluded: "Although the absolute increase in cancer risk among infertile women was small, this increase was seen in only a short period of four years of follow-up. We need to carry out further research with longer follow-up to determine what factors may be influencing the long-term risk of cancer for infertile women."
-end-
[1] "Risk of cancer in infertile women: analysis of US claims data", by Gayathree Murugappan et al. Human Reproduction journal. doi:10.1093/humrep/dez018.

European Society of Human Reproduction and Embryology

Related Breast Cancer Articles:

Breast cancer: AI predicts which pre-malignant breast lesions will progress to advanced cancer
New research at Case Western Reserve University in Cleveland, Ohio, could help better determine which patients diagnosed with the pre-malignant breast cancer commonly as stage 0 are likely to progress to invasive breast cancer and therefore might benefit from additional therapy over and above surgery alone.
Partial breast irradiation effective treatment option for low-risk breast cancer
Partial breast irradiation produces similar long-term survival rates and risk for recurrence compared with whole breast irradiation for many women with low-risk, early stage breast cancer, according to new clinical data from a national clinical trial involving researchers from The Ohio State University Comprehensive Cancer Center - Arthur G.
Breast screening linked to 60 per cent lower risk of breast cancer death in first 10 years
Women who take part in breast screening have a significantly greater benefit from treatments than those who are not screened, according to a study of more than 50,000 women.
More clues revealed in link between normal breast changes and invasive breast cancer
A research team, led by investigators from Georgetown Lombardi Comprehensive Cancer Center, details how a natural and dramatic process -- changes in mammary glands to accommodate breastfeeding -- uses a molecular process believed to contribute to survival of pre-malignant breast cells.
Breast tissue tumor suppressor PTEN: A potential Achilles heel for breast cancer cells
A highly collaborative team of researchers at the Medical University of South Carolina and Ohio State University report in Nature Communications that they have identified a novel pathway for connective tissue PTEN in breast cancer cell response to radiotherapy.
Computers equal radiologists in assessing breast density and associated breast cancer risk
Automated breast-density evaluation was just as accurate in predicting women's risk of breast cancer, found and not found by mammography, as subjective evaluation done by radiologists, in a study led by researchers at UC San Francisco and Mayo Clinic.
Blood test can effectively rule out breast cancer, regardless of breast density
A new study published in PLOS ONE demonstrates that Videssa® Breast, a multi-protein biomarker blood test for breast cancer, is unaffected by breast density and can reliably rule out breast cancer in women with both dense and non-dense breast tissue.
Study shows influence of surgeons on likelihood of removal of healthy breast after breast cancer dia
Attending surgeons can have a strong influence on whether a patient undergoes contralateral prophylactic mastectomy after a diagnosis of breast cancer, according to a study published by JAMA Surgery.
Young breast cancer patients undergoing breast conserving surgery see improved prognosis
A new analysis indicates that breast cancer prognoses have improved over time in young women treated with breast conserving surgery.
Does MRI plus mammography improve detection of new breast cancer after breast conservation therapy?
A new article published by JAMA Oncology compares outcomes for combined mammography and MRI or ultrasonography screenings for new breast cancers in women who have previously undergone breast conservation surgery and radiotherapy for breast cancer initially diagnosed at 50 or younger.
More Breast Cancer News and Breast Cancer Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

Risk
Why do we revere risk-takers, even when their actions terrify us? Why are some better at taking risks than others? This hour, TED speakers explore the alluring, dangerous, and calculated sides of risk. Guests include professional rock climber Alex Honnold, economist Mariana Mazzucato, psychology researcher Kashfia Rahman, structural engineer and bridge designer Ian Firth, and risk intelligence expert Dylan Evans.
Now Playing: Science for the People

#541 Wayfinding
These days when we want to know where we are or how to get where we want to go, most of us will pull out a smart phone with a built-in GPS and map app. Some of us old timers might still use an old school paper map from time to time. But we didn't always used to lean so heavily on maps and technology, and in some remote places of the world some people still navigate and wayfind their way without the aid of these tools... and in some cases do better without them. This week, host Rachelle Saunders...
Now Playing: Radiolab

Dolly Parton's America: Neon Moss
Today on Radiolab, we're bringing you the fourth episode of Jad's special series, Dolly Parton's America. In this episode, Jad goes back up the mountain to visit Dolly's actual Tennessee mountain home, where she tells stories about her first trips out of the holler. Back on the mountaintop, standing under the rain by the Little Pigeon River, the trip triggers memories of Jad's first visit to his father's childhood home, and opens the gateway to dizzying stories of music and migration. Support Radiolab today at Radiolab.org/donate.