NORTON: Incredible. It started off exciting and only got more so. When I was a medical student, people tried to convince me not to go into cancer medicine. Their reason was that they thought a cancer cell was so aberrant, with so many things wrong with it, that we’d never find a successful drug to attack it. But what we’ve been hearing here all week is direct proof that these people were wrong.
The best example is a new drug called Gleevec [Glivec internationally], designed to treat patients with chronic myelogenous leukemia, or CML, one of the main types of blood cancer. It was approved by the Food and Drug Administration for this use two weeks ago. What we learned at the meeting is that this drug is dramatically effective in treating an entirely different kind of cancer–an uncommon but aggressive gastrointestinal stromal tumor, called GIST, for which there’s never before been an effective therapy. In a study of patients who took it for three months last summer, the majority showed significant tumor shrinkage. We saw images of these cancers just melting away.
The drug targets certain abnormal molecules in the cancer cell that tell it to divide too often, creating tumors. These are actually proteins made by abnormal pieces of DNA. Gleevec works by moving through the bloodstream, entering the cell and attaching itself to these abnormal proteins and stopping them from telling the cell to divide. The meeting showed that a minimally toxic dose of Gleevec can be given by mouth to GIST patients with wonderful results. No therapy has ever done this before.
Some, such as nausea, but only at unnecessarily high doses. But the important thing about these new classes of drugs is that we can measure their biological effect. We can actually see what’s happening in the cell. We know when the growth signal in the tumor is turned off, and we don’t have to push the dose higher. We won’t be shooting in the dark so much.
It’s just a dramatically new approach. What this means is that we’re going to start to classify cancers by the cause of their malignancy, rather than their location. For example, we don’t say that a person has a lung or skin infection. We say they have a strep infection of the lung or skin. Strep is the cause, and the same antibiotic that will cure strep in the lung will work on the skin or anywhere else in the body. Similarly, we won’t talk of breast cancer anymore. We’ll talk of cancer caused by this or that DNA abnormality, which can be attacked with this or that drug, just as GIST or CML can be treated with Gleevec. This is a total shift. It allows us to pick the right therapy to attack a particular tumor, maybe even cure it.
We cure many cancers. The goal is to cure them all. Five or six years ago, when people asked, “Is it possible?” we’d have to be conservative and say we can’t expect major breakthroughs overnight. Many of us aren’t saying that anymore. Gleevec is an example. Advances, when they occur, can be dramatic. The reason is that the mystery of cancer is being solved. We now know what we have to do: find out what genes have gone wrong in all the various cancers, then build molecules to attack them. The human-genome project is now completed. We have the road map. All that’s left is the hard work of making this all come together to cure cancer.
Some diseases, like most bacterial infections, go away if treated with antibiotics. But we have people who have chronic infections and have to take antibiotics all their lives. I would be happier if I don’t have to use medications forever to control cancer, because drugs could eradicate each and every cancer cell. I think that’s certainly possible, and I’m not alone.
