- People with Lynch Syndrome are at high risk of
developing colorectal cancer and endometrial cancer
- Three out of every
100 colorectal cancer is caused by Lynch Syndrome
- Genetic testing of
colorectal tumors helps identify people with Lynch Syndrome
Lynch Syndrome is a genetic
condition that increases the risk of colorectal cancer
. A new study suggests
that healthcare providers support routine testing of colorectal tumors to
identify more people with Lynch Syndrome.
Genetic Testing of Colorectal Tumors Necessary?
‘Routine genetic testing for Lynch Syndrome for patients with colorectal cancer can improve identification of families at high risk of developing cancer.’
A study was conducted to
examine whether patients can opt out of the routine testing of colorectal
tumors. The study was conducted by Dr Yvonne Bombard, Genomics and Health
Services researcher in the Li Ka Shing Knowledge Institute of St. Michael's
Hospital. Surgeons, genetic counselors, oncologists, primary care physicians
and gastroenterologists were interviewed for their views and experiences on
colorectal tumor testing, results, counseling patients with Lynch Syndrome and
their families. The healthcare providers' vision for the design and
implementation of routine genetic
Some healthcare providers suggested
that patients should have the right to opt out of the routine genetic test for
Lynch Syndrome. But, some said it is necessary to carry out routine genetic
testing to help identify and manage patients with Lynch Syndrome and their
family members who might be at risk.
Healthcare providers who
supported that patients should be allowed to opt out of the routine test
pointed to the need to protect patients who test positive and may suffer
distress and insurance discriminations. There is also the need to avoid
unnecessary anxiety for patients who test negative. Providers also worried
about the long wait for appointments with genetic counselors for patients
identified with Lynch Syndrome.
Routine genetic test alone
may not improve the overall care for patients with Lynch Syndrome. Creating
awareness about the condition may help improve the overall care.
that the introduction of routine testing alone would not necessarily improve
care overall for Lynch Syndrome patients and their families. They felt that a
comprehensive approach was needed to increase awareness of Lynch Syndrome in
the wider medical community and that substantial change would need to occur to
improve coordinated care, adequate resourcing for genetic services and ongoing
surveillance, and provider awareness and education of Lynch Syndrome,"
said Dr Bombard.
"Many healthcare systems
are considering implementing routine testing for Lynch Syndrome for patients
with cancer to improve identification of families at high risk of developing
colorectal cancer for more intensive screening. This research will help guide how
these programs should be developed," said Dr Nancy Baxter, chief of the General
Surgery Department at St. Michael's and one of the paper's co-authors.
Limitations of the Study
Only a small number of
healthcare providers were interviewed for the study and patients' views were
not analyzed. Dr Bombard said that patients' views are needed to ensure that
their preferences were incorporated into the design of any program.
The study is published online
in the journal Genetics in Medicine.
Link Between Lynch
Syndrome and Colorectal Cancer
Genes such as MLH1, MSH2,
MSH6, PMS2, and EPCAM have been linked to Lynch Syndrome. A mutation in any of
these genes increases the risk of many types of cancer, particularly cancers of
the colon and rectum (colorectal cancer). People with Lynch Syndrome also have
an increased risk of cancers of the stomach, gallbladder, brain, skin, and
uterus (endometrium). Lynch Syndrome accounts for about three to five percent
of colorectal cancer cases. Three out of every 100 colorectal cancer is caused
by Lynch Syndrome. Early detection and treatment can reduce the incidence of
Genetic Tests for Lynch
Genetic testing is
recommended for people with a family history of Lynch Syndrome. Two genetic screening
tests are performed on tumors to identify people with Lynch Syndrome.
- Microsatellite instability testing (MSI)
- Immunohistochemistry testing (IHC)
- Should patients be allowed to
opt out of routine genetic testing of
colorectal tumors? - (https://www.eurekalert.org/emb_releases/2016-10/smh-spb100416.php)