It’s even harder than we thought

Today, the New England Journal of Medicine publishes a paper that shows that genetic mutations—the garbled DNA code that can kill you—often differs within the same cancer tumor. This is a huge deal.

Why?

Because dozens, if not hundreds, of academic scientists and start up companies and big pharmaceutical firms are working furiously to develop anti-cancer treatments based on genetics: drugs that target genes that help tumors to survive and grow, or tests that can identify which particular kind of genetic chaos distinguishes your cancer, so that they can tailor your regimen to your cancer’s patterns.

Genetic testing is the reason doctors advised me to do chemo and radiation after surgery, even though my tumor was less than a centimeter in diameter: Apparently, my cancer’s genetics were nasty. The fact that doctors could parse this out has always made me feel a little safer. I was amazed when I first learned that my cancer had its own genetics, separate from my normal cells. Now, I’m not sure whether to feel safe or scared. What if my “tailored treatment” only zapped part of my cancer?

Cancer genetics is now oncology’s great white hope, just as chemotherapy was in the 1950s and 1960s, and radical surgeries were in the decades before that. About 15 of these genetic drugs are on the market now, hundreds more are in various stages of clinical trials. But these drugs don’t always work, and this new study may explain why.

Every time we think we’ve got a bead on cancer, we seem to find some new way that it’s even more complex than we thought. How could chaos—essentially, that’s what cancer is—not be complex? You can think of the war on cancer as a great battle between the forces of destructive chaos and the forces of genetic order. Maybe this is why cancer captures the public imagination in ways that Parkinson’s disease and diabetes do not. Luke Skywalker where are you?

A team of scientists in the United Kingdom took biopsies from four kidney cancer patients. They took these samples from different parts of the same tumors. Then they ran extensive genetic testing on the samples, far, far more than was done my tumor samples, or is done on any other patient’s. Cancer genetics tests normally cost $5,000 to $10,000. The scientists did tests that cost about 10 times that, analyzing the tumors in far more detail than is usual. And it cost precious time: sequencing one patient’s entire cancer genome took a very big computer four months.

After all that time and expense, the researchers found that not only is each person’s cancer different, but that one tumor can be multifarious. The same cancer gene can have different mutations within the main tumor mass, or they may differ between the primary sites and places where the cancer has metastasized.

While the study is very small, only four patients given the expense, the Associated Press reports that independent experts say they expect to find similar differences in breast, lung and colon cancers. The University of Texas MD Anderson Cancer Center has amassed a genetic database of 4,000 patients. They have found similar discrepancies in 40 percent of the database’s breast cancer patients.

This doesn’t mean that genetic tests or treatments for cancer are a dead end, only that they may not be the one magic key that unlocks cancer’s secrets. I suspect that we will never find that one key, because chaos just isn’t that orderly.

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About leftbreast

I have had breast cancer. I was diagnosed at 47, and am now 49. I have finished "active treatment," two surgeries, chemo, radiation, monoclonal antibodies. These days, I only take a drug to suppress my uptake of estrogen, since my tumor was highly reactive to that hormone. I have been married to my husband Pete for 21 years. I have a stepdaughter, Maureen, 30, and a daughter, Erin, 10. I've been a freelance magazine journalist for 20-plus years, covering everything from Chinese foreign policy to Catholic nuns to endangered species. I have had a great life. I have lived in Asia and all over the United States. I have spent nights with tree-sitters in Oregon and with astronomers at the Mauna Kea observatory in Hawaii. I've been to a cocktail party on the poopdeck of a British destroyer docked in Shanghai. I've taken the bus to Tibet, and tramped through the cloud forests of Panama with biologists. A magazine sent me on a raft trip down the Colorado through the Grand Canyon; another sent me to cooking school for a week. I have spent time with celebrities, presidents and heroin dealers. I love my work. I have a loving, supportive family and more friends than I probably deserve. I have had the space and time to camp, ski, cycle, garden, cook and spoil my pets (an Australian shepherd, a German shepherd and a tabby cat). If it all ended tomorrow, I would have to say that it has been a really, really good ride. When I was in thick of treatment, I was simply fighting for more time. Now, I'm trying to connect the experience of cancer with the rest of my life, with the time that's been won. I hope the cancer never comes back, but if it does, I'll be ready. That's what this blog is about.
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2 Responses to It’s even harder than we thought

  1. kymlucas says:

    Even though the facts are kind of depressing, thanks for sharing this information.

  2. Lisa says:

    This information explains a lot – even if it is about chaos! I volunteer locally with the American Cancer Society and people in our small community are always asking or commenting about why can’t they find a cure or surely they have a cure, etc.. So, I have tried to explain to them that cancer cells are as individual as, well, individuals are and that one treatment might work for this cancer patient and not for the other and that other variables also determine a patient’s outcome. We just have to keep raising money to fund the many cancer research projects and keep hoping.

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