TORONTO, Aug. 4 /CNW/ - Research funded in part by the Canadian Cancer
Society may lead to a genetic screening test that could help families who are
at high risk for cancer.
Researchers have found that a recently discovered genetic occurrence,
called 'DNA copy number variation' (CNV), may be linked to an increased risk
of cancer in people with Li-Fraumeni syndrome (LFS), a hereditary disease that
already increases their susceptibility to cancer.
CNV refers to the variation in the number of copies (normally two) of a
gene or sequences of DNA in the genome of an individual. The variations have
been associated with susceptibility to certain diseases. This is the first
genome-wide study to look at CNVs and genetic susceptibility to cancer.
Because the study also found that CNVs can be detected in the blood, the
discovery paves the way for the development of a blood test to detect those
people with LFS at greatest risk of developing cancer.
"One of the challenges of caring for patients with Li-Fraumeni syndrome
is that it is difficult to predict when a cancer may develop," says lead
researcher Dr. David Malkin, a pediatric oncologist and senior scientist at
The Hospital for Sick Children. "These findings suggest that screening for
CNVs in families predisposed to cancer may help identify those who are at
highest risk and help us to detect any cancer early."
Heather Chappell, senior manager of Cancer Control Policy for the
Canadian Cancer Society says, "Early detection is critical because we know
that most cancers can be treated if they are caught early enough. This is
important research that is bringing us closer to answers and options for
people with Li-Fraumeni syndrome."
LFS is a rare hereditary condition that increases the risk of children
and young adults developing, most commonly, breast, brain, bone and soft
tissue tumours. However, the disease can be unpredictable. Different
individuals within a single family can develop tumours of varying severity, at
different body sites and at different ages.
Using the latest technology, the research team analyzed the DNA of
healthy individuals and families affected by LFS. The team found significantly
more CNVs present in LFS study subjects than in healthy subjects. They found
more CNVs in LFS patients who had already developed cancer and more CNVs in
the children of LFS parents. And perhaps most importantly, they found the
greatest number of CNVs present in Li-Fraumeni patients who had already
developed cancer compared to those who had not yet developed the disease. This
finding suggests a strong link between CNV frequency and the severity of the
cancers they develop. The researchers say the next step is to investigate the
link between CNVs and tumour development and progression, and to determine
whether similar findings are evident in other populations of cancer patients.
The Canadian Cancer Society has been a leader in research into
Li-Fraumeni syndrome, providing more than $2 million to Dr. Malkin since 1995
for his studies in this field.
This study is being published in the Aug. 5, 2008 issue of the
Proceedings of the National Academy of Sciences.
A survivor's story
Luana Locke isn't afraid to face her genetic destiny square in the eyes.
Li-Fraumeni syndrome runs in Ms. Locke's family, which has been
devastated by cancer. In fact, she is the only member of her family who has
had cancer and survived. She was diagnosed with breast cancer at the age of
25. Her children have also inherited the condition.
"As a cancer survivor and mother of two kids who will likely face a
cancer diagnosis in the near future, I'm happy that I've equipped myself
through genetic testing and screening with the best possible tools to deal
with all possible outcomes," says Ms. Locke.
It's been a difficult series of uphill battles since the diagnosis,
Ms. Locke admits. Most recently, her nephew passed away on his fifth birthday
earlier this year. However, she said that the "power of knowledge" has made
all the difference in the early detection of her syndrome and further research
means even more hope for her children.
"Whatever road LFS takes me down, I still celebrate that I'll never have
to lie awake at night and ask myself those questions as a parent. I'm doing
whatever I can to prevent my kids from being victimized by this disease. The
questions you ask, the answers you seek give me and others like me hope - hope
that the legacy of loss will, in the very near future, end."
The Canadian Cancer Society is a national community-based organization of
volunteers whose mission is the eradication of cancer and the enhancement of
the quality of life of people living with cancer. Last year, the Society
funded $49.5 million in leading-edge research projects across the country.
When you want to know more about cancer, visit our website at www.cancer.ca or
call our toll-free, bilingual Cancer Information Service at 1 888 939-3333.
For further information:
For further information: or to arrange an interview, contact: Judy
Noordermeer, Canadian Cancer Society, (416) 934-5691, firstname.lastname@example.org;
Alexa Giorgi, Bilingual Communications Specialist, Canadian Cancer Society,
(416) 934-5681, email@example.com