
January 18, 2008
In
November 2007, the Canadian NRU nuclear reactor in Chalk River, Ontario,
shut down for five days of routine maintenance. When the parts necessary
for repair were unavailable, the brief closure stretched into weeks. As
a result, the care of women diagnosed with breast cancer thousands of
miles away was threatened.
What does nuclear energy have to do with breast cancer treatment in
Boston, Dallas, or rural central California?
For
decades, breast cancer surgeons had one option to learn if a woman’s
breast tumor had been caught at an early stage or had already spread
outside of the breast. This information is critical; a tiny, localized
tumor can often be cured without toxic, rigorous chemotherapy. Breast
cancer that has spread beyond the breast requires very different
treatment. Before breast cancer can spread throughout a woman’s body and
threaten her life, it must make its way out of the breast and past the
body’s powerful first line of defense — the lymph nodes. These glands
are aggressive filters, but cancer cells multiply rapidly. Eventually
they overwhelm the ability of the lymph nodes to contain the dangerous
cells, and the cancer then spreads throughout the body.
The
first collection of glands that breast cancer cells try to move past is
in the underarm on the same side of the body. For decades, the operation
done by breast cancer surgeons required making a large incision in the
armpit to remove most of these glands. The lymph nodes were then tested
and the results guided treatment. Clean glands signified early, more
easily treatable disease.
A
woman’s survival depended on the accuracy of the staging information.
But
the staging procedure was problematic. The procedure left up to 40% of
women with persistent problems like arm swelling, pain, and numbness.
Some had nerve damage or formed scar tissue that interfered with
shoulder movement for years after surgery. Removing lymph nodes was
critical to breast cancer staging, but sometimes carried a high price.
In
the 1990s researchers and surgeons learned that some of the underarm
glands were more important than others in determining whether the breast
cancer had spread. If these important glands (“sentinel lymph nodes”)
could be identified, removed, and tested clean, then the operation
needed to stage a woman’s breast cancer would be less drastic.
Nuclear energy offered the solution to spare many women a difficult
operation.
A
liquid called “colloid” is treated in a nuclear reactor to add trace
amounts of radioactivity — typically, less than what a passenger is
exposed to during a transatlantic flight. When the medicine created by
this process is injected into the breast right before surgery, it
travels into the underarm and is trapped by the sentinel lymph nodes.
A
breast cancer surgeon in the operating room touches the woman’s underarm
skin with a special probe that beeps loudly when it senses the medicine
in the most important lymph nodes. Guided by the beeps, the surgeon then
makes a small incision to remove only a few glands, which are tested
while the patient is still under anesthesia. If the glands are clean,
the surgeon places a few stitches and applies a small bandage. For many
women with early breast cancer, no more staging surgery is needed,
allowing a quicker, less painful recovery.
But
this procedure depends on a supply of radioactive colloid. The vast
majority of the material used by American breast cancer surgeons comes
from a single nuclear reactor in Canada — a reactor that was shut down
for weeks.
In
December 2007, the American Society of Breast Surgeons issued an alert.
The reactor closure led to a shortage for hospitals across the country
whose doctors — and their patients — rely on the Canadian facility. When
the supply of radioactive colloid was exhausted, breast cancer staging
and treatment for American women would have to be delayed or altered.
But
the shortage did not affect only breast cancer patients. Radioactive
medication is the workhorse of nuclear medicine, a field essential to
the diagnosis and treatment of hundreds of diseases. Radioactive
isotopes are used to treat thyroid cancer, perform PET scans, check for
osteoporosis with bone scans, and diagnose heart disease (“chemical
stress test”) instead of using invasive angiograms.
According to Dr. Sandy McEwan, president of the Society of Nuclear
Medicine, “This is a catastrophe for patients. A lot of centers in the
U.S. are down to 20 or 30% of [nuclear medicine] capacity.”
Building a reactor in central California has been proposed. Such a
facility could generate more than simply energy and jobs; it would
provide a solution for doctors and their patients whose care is at the
mercy of a single building in Canada.
But
in 1976, California legislators issued a moratorium on the building of
nuclear energy plants, effectively banning the production of facilities
that could relieve the shortage sustained by American patients.
While the politics of nuclear energy are debated, women with breast
cancer wait and wonder.