
Should you test your genes?
“A moving target” is the way Dr. Robert Nickelson, an expert in hermatology/oncology with Willis-Knighton Health Systems, describes cancer.
“But that’s the future, and that’s good,” Nickelson said.
Some
women carry certain genetic changes in their BRCA genes that increase
their risks for getting breast, ovarian and other kinds of cancers at a
young age. BRCA stands for BReast CAncer susceptibility gene. There are
two BRCA genes: BRCA1 and BRCA2.
“They are known to repair DNA damage,” Nickelson said. “If
you
have a mutation, then the individual cannot repair DNA damage, so cells
that are rapidly dividing or changing on a monthly basis – breast and
ovarian – there is a better opportunity for the body to make a mistake
and be unable to correct it.”
Normally,
BRCA1 and BRCA 2 help protect you from getting cancer. But when you
have changes or mutations on one or both of your BRCA genes, cells are
more likely to divide and change rapidly, which can lead to cancer.
Until recently, it was thought these were the only two genes like this.
“At
the International Breast meetings this year, a fellow gave a stunning
lecture on the genetic risk factors for breast cancer,” Nickelson said.
“Basically, they have added four more genes to the pool.”
One
such gene is PALB2, which plays a critical role in homologous
recombination repair through its ability to recruit BRCA2 and RAD51 to
DNA breaks.
“It
actually helps BRCA1 sit on the DNAs, so if your PALB2 is damaged, then
even though you may have the BRCA functioning, it cannot sit in the DNA
as it should,” Nickelson said. “Then it can’t be repaired.”
Nickelson
said for a woman who is BRCA1 or BRCA2 positive, her risks for breast
cancer “increase astronomically – a 70 percent risk for breast cancer by
the age of 70.”
The
most at-risk fall in the age range of 30 to 45. Finding a “cancer
family” is important to treatment, so knowing your family history is
critical. But it has adverse
side-effects of its own. “There are decisions to make if you learn you are in a ‘cancer family,’” Nickelson said.
“If
a patient is adopted and has no knowledge of family medical history, a
human genome sequence is important in the diagnosis and treatment
process.
“If
she is a carrier of BRCA, that would change her treatment completely –
110 percent,” he said. “If you find a woman with one of these carrier
mutations, you have to sit down and start one of these whole
conversations about her children and so forth. It can get very involved
and very emotional.”
Depending on the patient’s age, her daughters could be very young.“So, you are suddenly
talking
about taking ovaries out of a young woman who hasn’t even had the
opportunity to have children yet,” Nickelson said. “It’s a risk
management thing. If they are at a high risk of developing ovarian
cancer, they may never get that chance. It’s a highly emotional time.”
Nickelson
said he deals with three types of people.“The people who want to know
everything, the people that get tested and there’s a finding, and then
the people who don’t want to know anything, despite the obvious,” he
said.
“At
some point, you have to think about your child – once you are past a
certain age, you’re really not in the picture any more,” he continued.
“This is for your child. You owe it to your family.”
At
some point in the near future, there may be a database to help
determine problem gene mutations.“It’s daunting, to say the least,”
Nickelson said. “Everybody will have to participate – every doctor,
every patient will have to put an effort into this. It’s how we’re going
to advance.”
– Bonnie Culverhouse
IMPORTANT NOTE:
Dr.
Robert Nickelson stressed cancer is not contagious, and a woman cannot
“give” it to her child. “It’s something that’s been in your family’s DNA
for generations,” Nickelson said.