Push is on to tailor cancer care to tumor's genes
By LAURAN NEERGAARD, AP Medical Writer Lauran Neergaard, Ap Medical Writer – Mon Feb 16,
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
"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
"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
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