Go to the website http://www.cancer.gov and select 'Cancer Types' on the top menu bar. Scroll down to 'Breast Cancer' and click. Select 'Cases & Prevention' from the options. Click 'More information' and select 'BRCA Mutations: Cancer Risk and Genetic Testing'. Use the information on this page to answer the following questions. As a special project, instead of selecting 'Breast Cancer' from the list of types of cancer, select another cancer you would like to know more about and produce a short summary of what you find.

Question

Accepted Answer

Welcome everyone. Here's our next question. Which of the following is true about driver mutations in cancer choice A, they're always inherited B, they are always, they always occur in oncogenes C. They are present in all cancer cells within the same tumor or D. They are acquired before the cancer metastasizes. Well, we want to recall from our content video that as we can, you know, remember by looking at the name driver mutations, the driver mutations are the initial genetic changes that cause a cell to show the apparent growth of cancer. So kind of that triggering mutation that begins the cancerous changes. Cancer tumors have a lot of genetic variation because often what they lose is that sort of controllability repairability. So once the cancer starts growing, they often develop many, many different mutations within the same tumor. Those later mutations are called passenger mutations. You've got your driver and you've got your passenger. But that's the key difference between them. The driver mutation is the one that initial change that begins transforming the cells into cancer cells. So with that in mind, let's evaluate our answer. Choices. Choice A they're always inherited. Well, this one's pretty easy to eliminate. Um These driver mutations can be inherited, but most often spontaneously arise in a person due to DNA damage um or other factors. So choice a not true about driver mutations. Choice B, they always occur in oncogenes. This one might be a little trickier to remember to rule out. Um But this isn't correct because of that word. Always again, when you're evaluating multiple choice questions, whatever you see in always, there should always be a little bit of a red flag. That's often a tricky word. That's going to turn a usually true statement into a false statement. And that's kind of the case here, driver mutations do often occur in, well, in what would be proto oncogenes. Once they've had the mutation that drives the cancer, they're then called oncogenes. So that's one thing that throws this off and they can occur in other types of genes as well, including um tumor suppressor genes that when these mutations occur in the tumor suppressor gene, they lose their ability to control cell growth and division. Then we have choice C they are present in all cancer cells within the same tumor. Again, we've got that word. All that like always can turn a mostly true statement into a false one. They are not present in all the cells of the cancer, all the cancer cells within the same tumor because again, those tumors have a lot of genetic variation. So they started the growth of the tumor. But various cells within the tumor can start to change and develop these passenger mutations in different ways. So the driver mutation just starts off the growth of the tumor. The tumor cells are not all clones of each other because of all those changes that occur. And then finally to d they are acquired before the cancer metastasizes. Well, it's our only answer left and it is the true statement because it is the initial mutation that causes the changes they do occur before metastasis occurs because that will be a consequence of the spread of this tumor that has started with that particular mutation. So again, which is true about driving mutations and cancer choice D they are acquired before the cancer metastasizes. See you in the next video.

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Key Concepts

Cancer Types and Classification

Genetic Mutations and Cancer Risk

Using Online Scientific Resources for Research