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Why the Genetics of a Tumor Matter

July 15, 2014

Growing up, we’re always told that we’re unique. Nobody else looks like you. Nobody has the same exact personality as you. Even your fingerprints are uniquely yours. No other person on this planet is exactly like you. But have you ever thought about why that is?

It’s because of our genetics. Our genes are what make us who we are. They give us our unique appearance, our spunky personality and even our predisposition for certain diseases and conditions. For those who have been diagnosed with cancer, their genetics could even help to save their life.

That’s right. Your genes are so unique that they can help doctors determine the best way to treat cancer. Pretty cool, right?

So, how is this possible? Well, first, let me start by explaining how cancer was treated 10 years ago, and then I’ll show you how that’s changed today:

How Was Cancer Treated 10 Years Ago?

Back in the 1990s and early 2000s—long before anyone had ever heard of a smartphone or an iPad—all types of cancer were treated the same way. Once the tumor had been found, doctors were only able to study it by looking at it under a microscope. That was it. A microscope was the only way that doctors could try to figure out how to treat a tumor.

Because of this limited technology, one patient’s tumor looked exactly like the next—which meant that everyone received the same type of treatment. Doctors would pick “the thing that was most likely to work” based on what worked for a previous group of people, instead of what worked for you. In essence, you were the same as everyone else. The result? Many cases of cancer were often overtreated or undertreated.

Now, obviously, undertreating a tumor can be bad because you’re not giving the patient all the treatment that they need. But you might be wondering, “Why is it so bad to overtreat a tumor? Doesn’t that just ensure that the cancer is gone for good?” Well, in theory, yes. But when doctors overtreat a tumor, it can significantly decrease a person’s quality of life—and if we do that, then we’ve failed just as much as if the cancer comes back.

How Do Genetics Affect Cancer?

Thankfully, all of that has now changed. Today, we are able to target tumors in a more specific way for the very reason that I mentioned earlier—genetics. For the past 20 years, doctors and researchers have been trying to learn more about genes and how they affect cancer—and we are finally there. Thanks to all of this research, we’ve learned that no two tumors are alike, just like no two people are alike. Each tumor is genetically different from the next.

So, how is this helping us change the way doctors treat cancer? Well, we’re still using that trusty microscope, but now, we can use something called stains too. Stains are a new type of technology that allow doctors to see how each tumor is different. Think of it as a window that lets us look inside the tumor. By using stains, we can look at the tumor’s different genes to see which ones are turned “on” and which ones are turned “off.”

Once we figure out which genes are activated and which ones aren’t, we can learn a lot about the cancer. The genes tell us what the tumor is doing and how it’s going to act down the road. So, for example, if we see that certain genes are turned “on,” we can predict that the cancer is going to be more aggressive.

How is Cancer Treated Today?

Now that we know each case of cancer is different, we can change the way we treat those cases. Today, we can pick the exact type of treatment that each patient needs, instead of just picking one type and hoping for the best.

So, for example, imagine if a patient with ovarian cancer is given a type of chemotherapy that isn’t right for her specific tumor. That would make what is already a challenging situation even more taxing. But thanks to genetics, doctors can now make sure they’re picking the right type of chemotherapy to spare patients from additional side effects and make the process less challenging for them.

In addition to helping doctors choose the right type of treatment, cancer genetics can also help us:

  • Determine whether the tumor is low or high risk
  • Decide whether radiation or chemotherapy is necessary
  • Spare people treatment when they don’t need it
  • Get patients additional treatment when they do need it
When it comes to treating cancer, we still have a lot of progress to make—but look how far we’ve come already. What wasn’t possible 20 years ago has now become a reality, and survival rates are higher than ever because of it.

To learn more about genetics and cancer, visit the American Cancer Society website.