Push Is On To Tailor Cancer Care To Tumor's Genes

By: By LAURAN NEERGAARD
By: By LAURAN NEERGAARD

WASHINGTON (AP) - The days of one-size-fits-all cancer treatment
are numbered: A rush of new research is pointing the way to tailor
chemotherapy and other care to what's written in your tumor's
genes.

Everyone with advanced colon cancer now is supposed to get a
genetic test before taking two of the leading treatments. It's a
major change adopted by oncologists last month after studies found
that those pricey drugs, Erbitux and Vectibix, won't work in 40
percent of patients.

Scientists are furiously testing similar genetically tailored
care in breast and lung cancer. It's a flurry of work that reflects
a huge problem: Most medications today benefit at best about half
of patients but it usually takes trial-and-error to tell.

That means a lot of people suffer side effects for nothing, and
it's incredibly costly. When the American Society of Clinical
Oncology recommended giving colon cancer patients that $300 test
for a gene called KRAS, it estimated the move could save a stunning
$600 million a year - by keeping drugs that cost up to $10,000 a
month away from patients who won't benefit.

Here's the critical consumer issue: As tantalizing as this
personalized medicine is, gene testing is like the Wild West.
Laboratories often introduce new tests at the first clues they
might work, not waiting for final proof. Few tests so far have won
the backing of major medical groups like ASCO, the cancer
specialists, making research studies a best bet for many patients.

"A bad test is as dangerous to a patient as a bad drug," notes
Dr. Richard Schilsky, ASCO president and a University of Chicago
oncologist. "The tricky part is to figure out which of those
(genetic differences) are clinically important and which are just
variations that exist."

This is not about testing if people carry so-called cancer genes
that make them prone to illness. Instead it's about finding a
tumor's genetic signature - a pattern of gene and protein activity
that signals if the cancer will grow fast or slowly, be more or
less likely to recur, and whether it would be susceptible to
treatment.

"We're getting into science fiction sort of, if now medicine is
being able to analyze things at the genome level," breast cancer
patient Claire Weinberg of Oxford, N.C., says in wonder.

A community hospital initially dismissed Weinberg's breast lump
but she fortunately sought a second opinion at Duke University
Medical Center - where, cancer confirmed, she enrolled in a study
of gene-directed chemotherapy.

"I felt it could only benefit me for them to know even more
about me," she says.

The ultimate goal: "What's the right recipe for those
patients?" explains Dr. Matthew Ellis of Washington University in
St. Louis, co-inventor of a different breast cancer genetic
approach.

Under study:

-A less precise test already can tell certain breast cancer
patients if they're at high or low risk of relapsing, helping the
chemo-or-not decision. But which chemo? Duke's Dr. Kelly Marcom is
genetically profiling breast biopsy tissue from nearly 300 newly
diagnosed patients headed for pre-surgery chemo. Some are randomly
assigned to one of two standard chemotherapy cockails; the rest get
the cocktail that matches their tumor profile.

It's too early to tell if the gene-directed approach helps more
tumors shrink.

But, "I can have no regrets," says Weinberg, who learned after
surgery that she'd been in the gene-tailored group and her tumor
shrank enough to save her breast. She's also getting post-surgery
chemo in case any rogue cells remain.

-Instead of custom profiling, an experimental test unveiled last
week examines 50 breast cancer genes to determine which of four
disease subtypes the woman has.

If it pans out - and much larger studies are planned - the
Breast Bioclassifier could change breast cancer's very names. When
studied on stored samples of old tumors, researchers found some
women safely skipped chemo - their subtype responded better to
post-surgery tamoxifen, or hormone therapy. A more aggressive type
was sensitive to most chemo choices but not hormone treatment, the
team reported in the Journal of Clinical Oncology.

And still another group didn't respond well to either care, a
group that desperately needs new options, said Ellis, who
co-developed the test with doctors at the University of Utah and
University of North Carolina, Chapel Hill.

-Next up, lung cancer. Hospitals nationwide are recruiting 1,200
lung cancer patients to study who carries extra copies of the
tumor-spurring gene EGFR. They'll get either of two top treatments,
Tarceva or Alimta, to see which is best for which genetic
condition.


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