Tag Archive for: germline mutations

What Do Prostate Cancer Patients Need to Know About Genetic Testing?

What Do Prostate Cancer Patients Need to Know About Genetic Testing? from Patient Empowerment Network on Vimeo.

 What should men with prostate cancer know about genetic testing? Expert Dr. Tomasz Beer explains inherited mutations versus cancer-specific mutations and discusses the roles they can play in the development of prostate cancer.

Dr. Tomasz Beer is Deputy Director at OHSU Knight Cancer Institute. Learn more here: https://www.ohsu.edu/people/tomasz-m-beer-md-facp.

See More From INSIST! Prostate Cancer

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Prostate Cancer Treatment Decisions: How Do Genetic Test Results Impact Your Options?


Transcript:

Katherine:

Excellent. Let’s talk a bit about genetic testing and the role it plays in prostate cancer. I’d like to start by defining a few terms that are often confusing for patients. First of all, what is a somatic mutation?

Dr. Beer:                     

Well, so let’s first start with what is a mutation. So, we all have DNA that is the code of life in every cell in our body in the nucleus of the cell, and that is where all of the encoding for all the genes that then identify the proteins that make up our cells in our body exist. A mutation is a change in the sequence of that gene of that DNA, a missing letter, or a letter that’s been replaced by another letter, that can lead to a faulty protein being made. Sometimes, a mutation can cause a protein to be activated inappropriately.

Otherwise, we can see situations where the protein is silenced and inactive when it’s needed. So, those are mutations. Now, somatic mutations occur in a cancer. The person does not carry those mutations in their genome. They’re not passed along to their children or inherited from their parents. They happen in the cancer itself, and that’s the nature of cancer. Many cancers have a propensity to accumulate mutations, and so, a somatic mutation represents a cancer-specific mutation.

Katherine:                  

What then is the difference between somatic and a germline mutation?

Dr. Beer:                     

Yeah. So, germline is an inherited mutation. That is a mutation that is in the genetic code that that individual is born with, almost always inherited from their parents.

And I say almost always because in rare circumstances, a new mutation emerges in the fetus and becomes a germline mutation, but almost always this is a mutation that’s inherited.

And an important thing to understand about those is that because it’s in the germline, in the parent DNA, that mutation is present in every cell in the body of that human being, including the eggs and sperm, and that’s how it’s then transmitted to the next generation. Those germline mutations, they predispose people to cancer, can turn out to be deleterious and can lead to the development of cancer, typically when an additional mutation develops, and the two together team up to begin the process of cancer development.

How Do Genetic Mutations Impact Breast Cancer Risk, Prognosis and Treatment?

How Do Genetic Mutations Impact Breast Cancer Risk, Prognosis and Treatment? from Patient Empowerment Network on Vimeo.

For breast cancer patients, how do genetic mutations impact risk, prognosis, and treatment? Expert Dr. Sarah Sammons provides insight about currently known genetic mutations and their impact on breast cancer care.

Dr. Sarah Sammons is an oncologist at Duke Cancer Institute and Assistant Professor of Medicine at Duke University School of Medicine. Learn more about Dr. Sammons here.

See More From INSIST! Metastatic Breast Cancer

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How Genetic Mutations Affect Metastatic Breast Cancer Prognosis and Treatment

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Transcript:

Katherine:

What are the known genetic mutations that can increase breast cancer risk?

Dr. Sammons:

Very good question. So, about 5 to 10 percent of all breast cancers are related to inherited genes. The most common ones that most patients have heard of, or most people have heard of in the media, are the BRCA1 and BRCA2, the BRCA genes. Those genes make patients highly susceptible to developing breast cancer throughout their lifetime. We’re talking 60 to 80 percent risk.

There are, over time, other genes that we have found also predispose patients to developing breast cancer.

There are over 10 at this point. Some of the most common ones are CHEK2, PALB2, PTEN, TP53, and CDH1. There are a few others, but those are kind of the main ones.

So, really when you develop a diagnosis of breast cancer, your oncologist and/or your surgeon will take a family history. They’ll keep into account your age, the type of breast cancer that you have, and we really have specific criteria now in which patients would qualify for genetic testing.

Genetic testing not only has become important to understand if you have a gene that could predispose you or your family to breast cancer, but we now have drugs that specifically target or are biomarkers for BRCA1 and BRCA2.

So, now it’s going to become even more important to test patients with early state and metastatic breast cancer because we have drugs that could actually specifically target BRCA.

Katherine:

How do these mutations impact a metastatic breast cancer patient’s treatment path?

Dr. Sammons:

Sure. Well, we can start with germline. So, really, right now, the only germline mutations that really impact a patient’s treatment are the BRCA1 and the BRCA2 genes. So, for patients that have germline mutations in BRCA1, we have a class of drugs called PARP inhibitors, that have been

shown to be more effective than chemotherapy in those patients. So, really, any patient that has a HER2-negative breast cancer – these genes are approved in HER2-negative breast cancer, so triple-negative or hormone receptor-positive breast cancer in patients that have a BRCA mutation.

It’s pretty critical to have this germline testing done because if they do have a mutation, then we would have a therapy for them that was more effective than chemotherapy. So, that’s why it’s important in that setting.

We’re also learning more and more, and research is evolving, that probably patients that have germline PALB2 mutations also may benefit from PARP inhibitors, but that data is still evolving.

In terms of somatic gene mutations, or next generation sequencing, your doctor might say that, “I want to send your tumor to look at the genes in the tumor that will help me decide what could be the next best therapy for you.” So, we would get a biopsy or use an old biopsy, and send your tumor to a variety of different companies that do this type of sequencing.

Some of them include FoundationOne, Curis, Tempus. And it would come back with a panel that would show what genes were mutated in your breast cancer.

About 40 percent of patients with hormone receptor-positive breast cancer have something called a PIK3CA mutation. And we have a drug called alpelisib (Piqray) that specifically targets that mutation.

Germline mutations usually also show up in the somatic testing. So, a BRCA mutation may also show up. The next generation sequencing also tests something called tumor molecular burden, which tells us basically how many mutations are altered in the DNA of your cancer. And we know that if you have many mutations, that you might be more likely to benefit from immunotherapy.

So, that’s another thing that we look at when we send that genomic sequencing. So, there are a variety of mutations and biomarkers that we can learn from sequencing the breast cancer, that will help us decide what’s the next best treatment for you in your metastatic breast cancer course.

Katherine:

What about prognosis, Dr. Sammons? Do these genes impact how a patient’s cancer may behave?

Dr. Sammons:

That’s a good question. The short answer is: Research is still evolving in this area, but I would say yes.

Katherine:

It sounds like it’s a qualified yet.

Dr. Sammons:

It’s a qualified yes. So, I would say for germline BRCA1 – we know that patients with germline BRCA1 are more likely to have triple-negative breast cancer.

So, in terms of early-stage disease, we know that triple negative breast cancer has a worse prognosis, a higher risk of coming back. But the FDA actually just approved PARP inhibitors in the early-stage setting for patients with BRCA mutations because it reduced the risk of recurrence.

So, where that settles out: Yes, we know that BRCA1 carriers are more likely to have triple-negative. Triple-negative is more likely to relapse, but every year we have newer and newer therapies that reduce the risk of relapse.

In the metastatic setting, BRCA carriers sometimes actually have been shown to live longer than patients without BRCA mutations because they’re more likely to respond to chemotherapy. We have the PARP inhibitor option – for all of those reasons.

In terms of gene mutations in the tumor, we do know that patients that have something called ESR1 mutations – so, if you have a hormone receptor-positive breast cancer, you have something called an ESR1 mutation.

We know that that means that you would be resistant to many of our endocrine therapies. And patients that have ESR1 mutations do usually have a shorter prognosis than patients that don’t.

So, there are a variety of mutations that are appearing to have impact on prognosis. 

How Does Biomarker Testing Impact Metastatic Breast Cancer Treatment Options?

How Does Biomarker Testing Impact Metastatic Breast Cancer Treatment Options? from Patient Empowerment Network on Vimeo.

How are metastatic breast cancer treatment options impacted by biomarker testing results? Dr. Jane Lowe Meisel explains germline testing versus somatic testing – and how results may be used to help determine optimal treatment.

Jane Lowe Meisel, MD is an Associate Professor of Hematology and Medical Oncology at Winship Cancer Institute at Emory University. Learn more about Dr. Meisel here.

See More From INSIST! Metastatic Breast Cancer

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Transcript:

Katherine:

What is biomarker testing, and how do results impact treatment options?

Dr. Meisel:

Great question. So, I think people often confuse germline mutations and somatic mutations. So, I’ll talk about that a little bit as we talk ab out biomarkers. So, I think biomarkers in general are factors within the tumor that allow us to make treatment decisions. So, if a biomarker in the tumor can predict response to a certain type off treatment, we want to know what that biomarker is so we can better treat the patient and more elegantly design a regimen. So, for example, having an estrogen-positive tumor, estrogen positivity is a biomarker suggestive of response to anti-estrogen treatments, which is why we give anti-estrogen therapy to ER-positive breast cancers.

But more recently, we’ve been able to move a little bit beyond estrogen, HER2 and triple-negative as our subtypes and think a little bit more in some patients about more sophisticated biomarkers. And that’s where somatic mutation testing comes in. So, there are germline mutations, which are inherited mutations that’re present in every cell in your body. So, for example, if your mother was a BRCA mutation carrier and based that BRCA mutation down to you, you would have a germline BRCA mutation. So, your cancer would carry a BRCA mutation, but so would every other cell you have.

And that’s a biomarker. That would make you a candidate for something like a PARP inhibitor. But in cancers, which the genes in the cancer have gone awry by definition, there are often other biomarkers within that tumor that may make you a candidate for certain treatments. And so, those mutations that arise in the cancer itself are called, somatic mutations. Those are mutations in the tumor, can’t be passed down to your offspring or anything like that and were not inherited by your parents. But mutations that’ve accumulated over time as these cancer cells have gone awry.

And so, genomic testing, or biomarker testing can be done often on a metastatic specimen. So, to be specific about it, say you had a metastatic breast cancer to the liver. You could have a liver biopsy done and that tissue from the liver biopsy could be sent for genomic testing. There are a lot of companies that do this and there are also some larger cancer centers that actually do in house testing for genomics. So, this testing can be done and what it does then is, it helps you determine, do you have a biomarker that predisposes you to a certain treatment.

So, if that metastatic liver tissues, for example contained high levels of PBL1 expression for example and you were triple-negative, that would say to your doctor ooh, this is a great candidate for immunotherapy along with chemotherapy. Or if you’re estrogen-positive for example and your tumor contains a mutation in the gene called PIK3CA and that might make you a candidate for a drug called, Alpelisib. So, these mutations could often be paired to a drug or treatment options, or sometimes to a clinical trial to allow patients to come take advantage of more targeted therapies. That sometimes, because they’re targeted, have fewer side effects than drugs that are a little more discriminate.

Katherine:

Marie sent in this question prior to the program, “Are there some genetic tests that’re more accurate than others?”

Dr. Meisel:

That’s a good question. I would say most genetic testing platforms have been heavily vetted and approved by national organizations and laboratories that’ve been tested multiple times before they’re allowed to be marketed. So, I wouldn’t say that one genetic testing program is necessarily better than another. I think that any of the commercially available platforms that’re used are probably pretty accurate.

I was just going to add one thing to that, if that’s okay. I was going to say that I think it’s important when you’re using genetic testing platforms though to know what you’re testing for. So, there are some platforms that will just test for say, the three most common mutations in BRCA1 and BRCA2 that Ashkenazi Jews have.

And so, if you get that testing back and you’re negative, you might think, “Oh, I don’t have a mutation in those genes.” Well, we know from that testing, just as an example, is that you don’t have a mutation in those three alleles of that gene. But if you haven’t had full gene sequencing, you could have a mutation somewhere else in that gene. So, I would say all genetic testing that’s commercially available is probably pretty accurate. But it is important when you get testing done to know what you’re testing for and what you’re not testing for so you can interpret your results accurately. And genetic counselors, as well as your doctors can help you do that. 

What Are Biomarkers and How Do They Impact Lung Cancer Treatment Options?

What Are Biomarkers and How Do They Impact Lung Cancer Treatment Options? from Patient Empowerment Network on Vimeo.

What are lung cancer biomarkers, and how do they impact treatment options? Dr. Isabel Preeshagul defines biomarkers and explains how different biomarkers may help determine treatment options and aid in predicting treatment response. 

Dr. Isabel Preeshagul is a thoracic medical oncologist at Memorial Sloan Kettering Cancer Center. Learn more about Dr. Preeshagul here.

See More From INSIST! Lung Cancer

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Transcript:

Katherine Banwell:

Well, let’s define a few terms that are often confusing for patients. What are biomarkers?

Dr. Preeshagul:

Those are somatic alterations in the tumor just like EGFR, or ALK fusions, or MET exon 14, or MET amplification, or KRAS G12C.

These are all genes that are altered in the tumor. And these are genes that drive the tumor to grow. There are also other markers like PD-L1, which is a marker for response to immunotherapy. And there are various markers.

I could go on and talk about it for hours, but those are the more common ones that we know how to treat and how to handle and prognosticate.

Katherine Banwell:

And another term that’s sometimes confusing, what is a genetic mutation?

Dr. Preeshagul:

So, for genetic mutations, you have germline, and you have somatic. So, a germline mutation may be something like a BRCA1 or a BRCA2 that we see in patients with breast cancer or prostate cancer versus a somatic mutation which would be EGFR that I had mentioned or ALK fusion. So, germline mutations are the ones that we worry about being heritable.

And somatic mutations are those that are not thought to be heritable but thought to happen spontaneously within the tumor itself and cause the tumor to grow. We are constantly learning more about these though, however. But it’s really important to talk with your doctor to see if you have a germline mutation or a somatic mutation or if you have both.

And it is never wrong to seek an opinion with a genetic counselor to make sure that everyone in your family is safe, that you’re up to date on age-appropriate cancer screening, and that your family gets screened appropriately as well if indicated.

Katherine Banwell:

Are there specific biomarkers that affect lung cancer treatment choices?

Dr. Preeshagul:

Oh, definitely. One that I had mentioned is PD-L1. And this is a marker that we look for expression. So, based on FDA approval for pembrolizumab, if you have an expression of 50 percent or more, you are able to get immunotherapy alone in the upfront setting. If you have less than 50 percent, we often give you chemotherapy plus immunotherapy. And that’s based on a clinical trial known as KEYNOTE-189.

Other markers such as EGFR, as I had mentioned, ALK fusions, RET, NTRK, MET exon 14, ROS1, KRAS, HER2, you name it, those are alterations that we look for ideally in the upfront setting as well and can really affect treatment planning.

And those patients that harbor mutations like EGFR and ALK and ROS1 or MET exon 14, we know that these patients do better with targeted therapy upfront, not standard-of-care chemo. So, it’s really important to know about the presence of these alterations before you start treatment if possible.