'Preimplantation Genetic Diagnosis 2018: Current Practice and Beyond', 9-10 November 2018
Page URL: https://www.bionews.org.uk/page_95119

Prenatal test detects cancer in mothers

20 July 2015
Appeared in BioNews 811

Abnormal results from a non-invasive prenatal test (NIPT) for fetal chromosome abnormalities may indicate the presence of previously undetected cancers in some mothers.

A study published in the Journal of the American Medical Association analysed the results of prenatal maternal blood tests where a high chance of fetal chromosomal abnormality had been indicated, but where no fetal abnormality in fact existed.

Out of 125,426 prenatal tests conducted between 2012 and 2014, about three percent (3,757) screened positively for one or more aneuploidies. Of these, only 39 women showed a multiple aneuploidy pattern that matched cancer cases that had already been reported, and in 16 of these the fetus turned out not to have the abnormalities detected in the NIPT.

Seven out of these 16 women were later diagnosed with cancer, leading the researchers to estimate that 20–44 percent of cases in which the mother's blood sample does not 'match' the fetal karyotype will be because of the mother's previously undiagnosed cancer. The study also revealed three cases in which a single abnormality result occurred and maternal cancer was later diagnosed.

The results were obtained from Illumina's NIPT test (sold under the name Verifi), which screens for the presence of whole-chromosome aneuploidy for chromosomes 13, 18 and 21. It can also test for sex chromosome aneuploidy by considering sequencing counts for chromosomes X and Y.

In common with other NIPT screenings, the Illumina test uses the discovery that cell-free fetal DNA can be detected in maternal plasma, but can be separately analysed to provide information on the fetus.

While Illumina is adamant that its test is a fetal screening tool and not a diagnostic test, the results were published after rival company Sequenom revealed earlier in the year that its prenatal blood test had detected potential cancer in at least 40 expectant mothers since its launch three years ago. Sequenom is developing a related cancer test (see BioNews 793).

The potential detection of cancer as a secondary finding gives rise to a number of ethical issues about false positives, over-diagnosis and how women and clinicians should be expected to deal with their results (see BioNews 797).

Professor Diana Bianchi, lead author of the study and executive director at the Tufts Medical Centre, comments that 'until further studies are done to assess the clinical implications of discordant NIPT and fetal karyotype results, it is not clear what, if any, follow-up clinical evaluation is appropriate'.

Dr Roberto Romero of the Eunice Kennedy Shriver National Institute of Child Health and Human Development and Professor Maurice Mahoney of Yale University School of Medicine agree. In an editorial accompanying the study, they comment that 'at this time, there is insufficient evidence about the benefits, risks, and costs of reporting the incidental findings'.

They also note 'given that it is likely that NIPT will increase in the coming years, an active dialogue among stakeholders needs to take place to provide informed advice to potentially affected pregnant women and to guide their care'.

SOURCES & REFERENCES
In Tufts Study, 10 Cancer Cases Found Among 125K Illumina NIPT Customers
GenomeWeb |  14 July 2015
Noninvasive Prenatal Testing and Incidental Detection of Occult Maternal Malignancies
Journal of the American Medical Association |  14 July 2015
Noninvasive Prenatal Testing May Also Detect Some Maternal Cancers
Tufts Medical Center (press release) |  13 July 2015
Prenatal Blood Tests Could Detect Cancer in Mothers
Wall Street Journal |  13 July 2015
When a Fetus's Test Finds a Mother's Cancer
MIT Technology Review |  13 July 2015
RELATED ARTICLES FROM THE BIONEWS ARCHIVE
15 August 2016 - by Dr Nicoletta Charolidi 
A study has shown that the chemotherapy drug etoposide can affect the development of fetal ovarian tissue in mice...
18 July 2016 - by Amina Yonis 
Non-invasive prenatal testing (NIPT) is improving all the time, and the tests may soon be offered to all pregnant women on the NHS. This event explored how to ensure that prospective mothers are properly counselled to make informed decisions about their pregnancy...
15 February 2016 - by Helen Robertson 
A blood test to diagnose common types of cancer is in development after researchers found that five forms of the disease share a telltale chemical signature...
25 January 2016 - by Vardit Ravitsky, Jessica Mozersky, Marsha Michie, Rayna Rapp, Megan Allyse, and Subhashini Chandrasekharan 
Since its introduction in 2011, the availability of non-invasive prenatal testing has been expanding globally and rapidly. The clinical introduction of NIPT has clear benefits for pregnant women, such as reducing the need for invasive testing. But, depending on local circumstances, it also raises varying challenges and opportunities...
18 January 2016 - by Lone Hørlyck 
A new blood test for Down’s syndrome in high-risk women has been recommended for use on the NHS....
22 June 2015 - by Jane Fisher 
There has been much recent media interest in non-invasive prenatal testing for Down's syndrome, and this coincides with deliberations by the UK National Screening Committee on its potential inclusion in the NHS Down's syndrome screening programme...
22 June 2015 - by Ceri Durham 
A US federal appeals court has upheld a ruling that Sequenom's prenatal MaterniT21 test is not sufficiently 'inventive' to be patentable....
8 June 2015 - by Kirsty Oswald 
Researchers say that a non-invasive prenatal test for Down's syndrome is ready to be introduced into the NHS...
13 April 2015 - by Kirsty Oswald 
Research shows that a new prenatal blood test for Down's syndrome outperforms current methods of screening...
9 March 2015 - by Kirsty Oswald 
US company Sequenom has revealed that its prenatal blood test - MaterniT21 PLUS - has detected potential cancer in at least 40 expectant mothers since its launch three years ago...
HAVE YOUR SAY
Log in to add a Comment.

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


Syndicate this story - click here to enquire about using this story.