The results follow a review of the largest number of PGD treatments for BRCA1/2 in Europe and were presented today at the annual meeting of ESHRE (European Society of Human Reproduction and Embryology) by Professor Willem Verpoest from the Centre for Reproductive Medicine at Vrije Universiteit Brussel, Belgium.
Behind his vote of confidence lie 145 PGD cycles for BRCA1/2 mutations performed in 70 couples at the two centres (a mean of 2.1 cycles per woman). Almost 60% of the mutation carriers were female, two-thirds with a BRCA1 mutation. Just over one quarter (26.2%) of female carriers had undergone a prophylactic bilateral mastectomy.
Following IVF, 717 embryos were found suitable for genetic analysis, and of these 43.1% were diagnosed as affected by the mutation, with 40.7% unaffected and thus suitable for transfer (the remainder had an abnormal genotype or the analysis was inconclusive). Hence, 62.1% of the PGD cycles led to fresh embryo transfer - with 3.6% transferred from one or two frozen-thawed unaffected embryos - resulting in 42 pregnancies in 40 women. Pregnancy rates were 41.4% per fresh embryo transfer and 23.1% per frozen. The overall pregnancy rate was 29%.
The series also included three cases of PGD on embryos previously cryopreserved for fertility preservation prior to chemotherapy, and these too resulted in two ongoing pregnancies.
Two female BRCA1 carriers were diagnosed with breast cancer within three months of the PGD treatment, despite breast screening shortly before treatment. One had a history of breast cancer, the other patient hadn't. The former patient went on to have healthy twins three years after the second breast surgery and chemotherapy, and following frozen/thawed embryo transfer.
So far, PGD for BRCA1 and BRCA2 gene mutations has been considered controversial. While most PGD procedures are indicated to remove completely the risk of inherited sex-linked and single-gene diseases (such as cystic fibrosis) in the children of affected couples, PGD for the breast cancer mutations cannot remove the risk completely - because the 10% background risk of breast cancer remains, even after PGD. Moreover, breast and ovarian cancers are usually of late onset, with prevention and therapeutic options constantly improving - so the chances of successful treatment, and many years of healthy life, are high.
Nor is breast cancer inevitable for a woman (or man) carrying a BRCA1/2 mutation. The controversy thus rests on the fact that a mutation in the BRCA genes increases susceptibility to breast or ovarian cancer, but does not reflect an inevitability for developing the diseases. However, with female carriers of a mutation in either gene having a lifetime risk of 60-80% for breast cancer, and a risk of 30-60% (BRCA1) or 5-20% (BRCA2) for ovarian cancer, many authorities have recognised the gravity of the risk and accepted a BRCA gene mutation as an indication for PGD.
So far, only five pregnancies after PGD for BRCA1/2 have been reported since the first was described in 2008.(1) The slow uptake reflects not just the controversial nature of the procedure, but also concerns over patient selection and the safety of hormonal stimulation for IVF in women at risk themselves of breast and ovarian cancers.
Professor Verpoest emphasised that the results, representing by far the biggest series of PGD for breast cancer in Europe, are robust, with a good unaffected pregnancy rate.
"We now believe that this technique offers an established option for those couples seeking to avoid the risk of inherited BRCA in their children," he said. "However, although there is no evidence of increased carcinogenesis in patients having ovarian stimulation for PGD in this population, the screening and monitoring measures - as well as multidisciplinary management - must still be in place.
"Our results suggest that PGD for BRCA1 and 2 mutations is feasible, with a good treatment outcome, but controversy will still remain over the ethical acceptability of PGD for a susceptible - yet preventable - condition."
1. See http://news.bbc.co.uk/1/hi/health/7792318.stm
From abstract no: O-191 Tuesday 3 July 2012, 17.00 hrs EEST Feasibility of preimplantation genetic diagnosis for hereditary breast and ovarian cancer: report on a large cohort study
Note: When obtaining outside comment, journalists are requested to ensure that their contacts are aware of the embargo on this release.
The 28th Annual Meeting of ESHRE, the world's largest event in reproductive science and medicine, is taking place in Istanbul from 1-4 July 2012
Christine Bauquis | EurekAlert!
Biofilm discovery suggests new way to prevent dangerous infections
23.05.2017 | University of Texas at Austin
Another reason to exercise: Burning bone fat -- a key to better bone health
19.05.2017 | University of North Carolina Health Care
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.
In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
24.05.2017 | Physics and Astronomy
24.05.2017 | Physics and Astronomy
24.05.2017 | Event News