Around 400 B.C., Hippocrates theorized that cancer was a single disease that would not fully go away, in most cases, even after it was surgically removed. That’s why, for centuries after the scholar’s death, cancer often went untreated for fear that interventions would do more harm to the patient than good. Much has changed since then, thanks to advances made in the last century—especially in the area of precision medicine in the last two decades. Yet despite new evidence to the contrary, some people today still believe that cancer is just one disease. Many of those who subscribe to this myth can’t fathom why researchers haven’t figured out how to cure cancer yet. But what research has shown is that cancer is not just one disease but many, each with its own characteristics, risk factors, causes and treatments.
“The human mind tends to seek easy-to-understand answers. But cancer is just a name for cells that are rapidly dividing without regard to the body. Each cancer behaves differently based on many factors, and even cancers from the same site of origin, like breast cancer, can be radically different depending on their unique molecular profiles,” says Eugene Ahn, MD, Medical Director of Research and Hematologist/Oncologist at our hospital in Chicago
The word “cancer” actually refers to a collection of more than 100 different diseases, with wide-ranging and varied characteristics that may call for wide-ranging and varied treatments. For example, many prostate and breast cancers respond to hormone therapies that prevent cancer cells from getting the hormones they need to grow. But lung cancer does not generally respond to hormone manipulation treatment, and is instead more often treated with surgery, chemotherapy, radiation therapy, immunotherapy or targeted therapy, either alone or in combination. On the other hand, some drugs are used to treat several kinds of cancer. “Sometimes, drugs overlap and can work for different cancer types, but that’s something that has to be proven through clinical research, because it’s certainly not safe or reasonable to assume that one drug is going to work for every cancer type just because it works for one,” Dr. Ahn says.
Evidence that the drug or therapy works is important, Dr. Ahn says. Still, many cancer patients and their caregivers are tempted to try relatively unproven techniques, such as a radical dietary change, because they seem like quick, easy fixes, despite the lack of evidence that they consistently work. “Cancer is a complicated topic,” Dr. Ahn says. “We’re still learning a lot about each cancer type each year, and it can get very complicated for anyone who gets diagnosed and is looking for solutions. So it can be easy to be drawn into simple narratives or quick-fix solutions that claim to provide magic bullets. A common mistake we see is when a study comes out showing that a dietary change works for a certain cancer type in animals, and people believe that it must therefore work for that cancer type in humans. But one thing most oncologists and scientists know to be true is that it is far easier to cure cancer in animals like mice, in cases when the disease is artificially induced, than it is to cure cancer in humans, in cases when the disease occurs naturally.”
Although there’s something attractive about the simplicity of alternative medicine approaches, cancer patients should use healthy skepticism and be their own advocate when it comes to curative claims that aren’t based on science, Dr. Ahn says. “Be very cautious and use your judgment when you read an article that claims to have found the one cure for cancer,” he says. “There tends to be an assumption that if it’s in the media or on the internet, it must be important, but that’s not always true. And if the sources talk about cancer as only one disease, odds are they don’t fully understand cancer.”
