All women undergoing treatment for womb cancer are to be offered tests for an inherited genetic condition. New guidance from NICE was published on 28 October. It follows research that showed that almost all women invited to have the test took up the offer.
Around three to four in 100 women with womb (endometrial) cancer have Lynch syndrome. This means they carry a defect in a mismatch repair gene, and DNA is not always copied correctly when cells divide. The syndrome increases the risk of both womb and bowel cancer. At present, people diagnosed with bowel cancer are routinely offered screening for Lynch syndrome, but women with womb cancer are not.
Women with Lynch syndrome are likely to develop womb cancer before showing signs of bowel cancer. A diagnosis of the genetic condition means they can be offered regular checks, and aspirin therapy, to reduce their risk of bowel cancer.
Researchers found that, of 305 UK women offered testing for Lynch syndrome around the time of their treatment for womb cancer, 302 accepted.
Women’s family members can also be offered testing. The researchers found that protecting family members was the main reason why women wanted to be tested. They were most receptive at follow-up appointments after surgery for their womb cancer.
What’s the issue?
More than 9,300 women are diagnosed with womb cancer in the UK each year. A small proportion of them will have Lynch syndrome, an inherited condition that raises the risk of several cancers but most often womb and bowel cancer.
There has been little previous study of the acceptability of testing for Lynch syndrome among women with womb cancer. Research from the US showed only about half of women offered testing accepted it. However, this may be because of the impact of a Lynch syndrome diagnosis on healthcare insurance premiums.
Researchers wanted to see if UK women with womb cancer wanted Lynch syndrome testing, and whether this could be offered routinely as part of their gynaecological cancer care.
Samples of tumours can be tested for possibility of Lynch syndrome, but definitive testing requires a blood test. At present, these blood tests are only offered to women with womb cancer after they have been referred for genetic counselling. This contrasts with the situation for bowel cancer, where everyone diagnosed is offered tumour testing followed by blood testing if they screen positive.
Almost all of 305 patients with womb cancer attending a specialist gynaecological cancer service in the North West of England, agreed to have testing for Lynch syndrome. Only three declined, and one later changed her mind. 13 women tested positive for Lynch syndrome.
The women were recruited as consecutive patients attending the service. They were given information about Lynch syndrome and offered testing. They were also asked about their reasons for wanting to be tested, and they filled in questionnaires recording their anxiety levels when they were asked about testing.
Not all women needed a blood test. Only about a quarter of those who consented to testing actually had the blood test. The other women could be ruled out for Lynch syndrome on the basis of their tumour sample alone.
Women’s prime reason for wanting to be tested was to protect their families. Family members who might carry Lynch syndrome could be checked, and be offered treatment and surveillance if they tested positive.
Women’s anxiety levels were highest when testing was offered on the day of surgery, before the operation, or at diagnosis. Women were least anxious if offered testing at their routine follow-up appointment.
Only 215 women returned the questionnaires, and only 175 completed them in full. This might affect how widely the results can be generalised.
It took around eight minutes for gynaecologists to explain the test and for women to agree to have it.
Why is this important?
The study has informed NICE guidelines, which now recommend Lynch syndrome testing for all women with womb cancer. This will enable women with the syndrome to take part in surveillance programmes of colonoscopy, to check for signs of bowel cancer, and to be offered aspirin treatment to reduce the chances of the disease. It will also mean women’s family members can be tested to see if they have Lynch syndrome.
Alongside this study, the researchers have carried out research to show how many women with womb cancer have Lynch syndrome, and to assess the cost effectiveness of Lynch syndrome testing for these women. These studies have also informed NICE’s new guideline.
Gynaecologists treating women with womb cancer will need training in how to ask women for informed consent for this genetic test. Emma Crosbie, one of the authors of the study, says this could be delivered as a one-hour online training session. Follow-up appointments after womb cancer surgery will need to allow time for this discussion. The researchers estimate it will lengthen appointments by an average 10 minutes.
The new guidance is likely to lead to an increase in referrals to genetic counsellors among women who test positive. They will need to discuss the implications of the result and discuss who in their family should be offered testing. It is likely to increase the numbers of tests for Lynch syndrome being carried out by pathology departments, and the numbers of women referred to bowel cancer prevention programmes.
You may be interested to read
The full paper: Ryan NAJ, and others. Feasibility of Gynaecologist Led Lynch Syndrome Testing in Women with Endometrial Cancer. J. Clin. Med. 2020;9:1842
A study by the same authors about prevalence of Lynch syndrome: Ryan NAJ, and others. The proportion of endometrial tumours associated with Lynch syndrome (PETALS): A prospective cross-sectional study. PLOS Medicine. 2020;17:e1003263
Ryan NAJ, and others. A mismatch in care: results of a United Kingdom-wide patient and clinician survey of gynaecological services for women with Lynch syndrome. BJOG. 2020. doi: 10.1111/1471-0528.16432
Dominguez-Valentin M, and others. Risk-Reducing Gynecological Surgery in Lynch Syndrome: Results of an International Survey from the Prospective Lynch Syndrome Database. J. Clin. Med. 2020;9:2290
NICE diagnostics guidance. Testing strategies for Lynch syndrome in people with endometrial cancer. DG42. 2020
NICE diagnostics guidance. Molecular testing strategies for Lynch syndrome in people with colorectal cancer. DG27. 2017
More information and videos about Lynch syndrome testing, Manchester University
This research was co-funded by the NIHR Manchester Biomedical Research Centre and the Medical Research Council.