FOR PATIENTS, SURVIVORS AND FRIENDS
Genomic Analyses Support Association Between Early Puberty and Cancer Risk
A new study that used data from the 1000 Genomes Project identified 389 genetic variations associated with the age
when girls begin menstruating. Additional analyses linked these variations to 33 genes, some of which are paternally
inherited. The researchers concluded that these findings add to the evidence that genetic variations, independent
from other factors, influence the timing of puberty. The findings also support previous links found between genetic
variations, early puberty and later development of breast and endometrial (uterine) cancer.
LEARN MORE IN THE ONLINE FIRS T APRIL 24, 2017, NATURE GENETICS.
The Lung Cancer Navigator, developed by
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questions to ask health care providers. The app
also provides links to the latest medical and
Keep track of side effects with the
Cancergraph app, developed by Malecare Inc.
By charting daily experiences, cancer survivors
obtain detailed information about their progress,
which they can share with caregivers and their
health care team. The app also allows patients to
make their data available to cancer researchers
and to be matched with appropriate clinical trials.
HER2-positive breast cancer survivors
can learn more about their cancer with the
new 4HER Patient Support app, developed by
Genentech. Survivors also can use the app to
share information and get support from other
breast cancer patients.
then how do we avoid getting cancer until
age 50? The reason is because of natural
selection. Tumor suppression is the norm
in younger people because that is when
they are going to reproduce.
Q: So the mutations just sit around until
something triggers them?
A: We can’t avoid mutations. They
are part of the evolutionary natural
selection process. We are riddled with
mutations, some of which are potentially oncogenic (cancer-causing). It’s
not a matter of whether we have them;
it’s a matter of whether they do harm.
The vast majority of them don’t. The
reason we get cancer later in life is the
same reason we are no longer reproducing later in life: During our youth,
when we are most likely to reproduce,
our cells maintain our bodies well, and
that maintenance helps prevent cancer.
When we are young, the microenvironment that surrounds oncogenic cells is
not conducive to tumor growth because
it favors normal cells over cancer cells.
Q: So the problem is aging?
A: What we are arguing is that as we
age, our tissues change, no matter how
well we take care of ourselves. And
these changes create a microenvironment that favors cancer cell growth.
Q: Then why do babies and kids
A: The hygiene hypothesis is one
potential explanation for why child-
hood leukemia is around five times
more prevalent in places like the
U.S. than in poor Caribbean nations
and sub-Saharan Africa. The idea is
that in developed countries, children
don’t experience the same insults
to the immune system in their first
year of life. Then as they get older,
their immune system overreacts,
and it is this inflammatory response
that could create an environment for
oncogenic cell growth and leukemia.
Q: What does your hypothesis
mean in terms of cancer prevention
A: Fitness of tissue is what prevents
cancer. Smoking, for example, damages
tissue. Not smoking keeps tissue fit.
Whether you believe cancer is caused
by mutations or that there are changes
in the microenvironment, it doesn’t
change the advice—don’t smoke. We are
presenting a different explanation for
why that advice is important. In terms
of treatment, right now we focus on
targeting cancer cells. But we could
also find a way to establish an environment that is less conducive to the cancer
cells. From an evolutionary biology
approach, immunotherapy is a great
example. It is changing the ecosystem
(getting the microenvironment to go
after cancer cells) and not changing
the animal (the cancer cell itself).
Q: Could we evolve enough to not
A: We evolved to not get cancer
through our youth, but that was
selected for over millennia. Because
most cancers occur later, they don’t
limit reproductive success. We didn’t
evolve to age indefinitely—our cells’
maintenance programs wane with
time. You can’t eradicate cancer,
but you can try to limit it and treat
it. Cancer has no goals. It is not
trying to kill us. It is just adapting to
circumstances. If we can figure out
how to direct its evolution, then we
can change it. —SUE ROCHMAN