Photo: Plamen Petkov
What if a simple test could detect cancer in its earliest stages—and reveal exactly which treatment would have the best chance of curing you? Welcome to the age of personalized medicine.
For decades, scientists thought of cancer as simply a disease of good genes gone bad. Whether a person's DNA contained inherited mistakes or became damaged as cells went about their daily business, these glitches allowed cells to multiply unchecked. If they could find a way to stop the cells from reproducing, scientists assumed, they could cure the cancer. But today it's clear that the mechanisms behind the disease are far more complex. Oncology researchers have discovered that a tumor's growth is as much a product of its surrounding environment as it is of genetics. Research has also shown that even when two people have the same type of malignancy, the cellular changes that cause their tumors may be unique to each patient.
Although such findings suggest there may never be a universal cure for cancer, they have paved the way for more precise screening tests and more effective treatments. "We're on the brink of genuinely changing cancer treatment for the better," says Razelle Kurzrock, MD, head of the department of investigational cancer therapeutics at the University of Texas M.D. Anderson Cancer Center in Houston.
Already, targeted therapy—medications aimed at specific cells with certain mutations or other characteristics—is being used in some cancer treatment centers, and it will only become more common as the decade goes on. "In the past five years, we've realized that there's no 'one size fits all' when it comes to cancer," says Eric Winer, MD, director of breast oncology at the Dana-Farber Cancer Institute in Boston.
In fact, "we're heading to the day when cancer treatment will look a lot like modern infectious disease treatment," Kurzrock says. Not so long ago, nearly all patients with bacterial infections got penicillin. But just as doctors can now analyze a culture of your infection and match an antimicrobial drug to your particular germ, oncologists will one day be able to obtain your tumor's genetic fingerprint and devise a specialized drug regimen just for you.
The next step will be identifying more cancer triggers to target. The breast cancer drug Herceptin, FDA approved in 1998, was one of the first treatments developed to home in on a specific genetic flaw—in this case, a defect in the HER2 gene, which is responsible for about 20 to 30 percent of breast cancers. A decade of experience with Herceptin and similar drugs has demonstrated that treatment can be more effective and have fewer side effects when it hits a precise genetic mark—but we've also learned that most cancers are likely driven by more than one mechanism. Today researchers are working on drug cocktails that can hit several bull's-eyes at once. Early trials suggest some of these drug combinations are more effective at shrinking tumors and halting disease progression than existing medications.
In the next decade, the best treatment for some patients may be no treatment at all
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