Heather Cheng, M.D., PhD, Director of Prostate Cancer Genetics Clinic at Seattle Cancer Care Alliance and assistant Professor of Medical Oncology at University of Washington, talks about how a new study is suggesting men may be at a higher risk for advanced prostate cancer if women in their family had female cancers.
Interview conducted by Ivanhoe Broadcast News in September 2016.
Tell us about the exciting new study that was done and what you have found.
Dr. Cheng: The study was performed by an international collaborative group and led by investigators at the University of Washington, Fred Hutchinson Cancer Center and Seattle Cancer Care Alliance. We studied 692 men with advanced metastatic prostate cancer and found that the prevalence of inherited cancer risk genes was almost twelve percent. It was eleven point eight percent.
Tell us about the exciting findings and the importance of prostate cancer and genes.
Dr. Cheng: We, as part of an international collaborative group, determined that of almost seven hundred men with metastatic advanced prostate cancer that is life threatening almost twelve percent of them have an inherited cancer risk gene that is important to their prostate cancer. This is a surprising finding. The genes discovered as part of this study are many of the same genes that are known to be important for breast and ovarian cancer risk. One of the take-home messages is really that a family history of female relatives with breast and ovarian cancer is just as important for men to know about as a family history of prostate cancer. The other important result of the findings is that if we find one of these mutations in a man with advanced prostate cancer, we have new treatment options that are expanded beyond what men would normally have for prostate cancer care.
Everybody has kind of heard of breast cancer, the breast cancer gene, what do you want people to know?
Dr. Cheng: Genes like BRCA2 and BRCA1 are best known as breast and ovarian cancer risk genes, but now we know that these genes are also important for prostate cancer. It is vital that men be aware of their family history of cancer and tell their doctors and share that information within the family so that they can be tested if it’s appropriate.
This is a big deal because for years men didn’t necessarily come in and talk about their mom, their grandma.
Dr. Cheng: That’s right, I think because of the way these genes were first identified in families with breast and ovarian cancer and how the studies were done and the technology available. We’ve known for some time that men can also get breast cancer but we’ve underappreciated the role of these genes in men who get prostate cancer, especially aggressive prostate cancer. We’re learning that it can make a big difference for treatment. Also there are some families where the prostate cancer is what appears more than breast and/or ovarian cancer, and we need to study this further. It’s also important to emphasize that some of the men in our study did not have any family history of cancers, so while it’s important to know your family history, men with advanced prostate cancer should still talk with their doctor about whether genetic testing should be done.
Was this pretty surprising to all of you researching this?
Dr. Cheng: It was really surprising. We’ve known for a long time that prostate cancer is familial. There’s cancer risk runs in families but we didn’t have as much information as we do now to suggest changes to management.
The key like for all cancers is what?
Dr. Cheng: Early detection, and being aware of cancer screening and talking to your doctor. The PSA screening guidelines have been undergoing some changes but I think what can be lost in that is that if you have an increased risk based on your family history or because you have one of these mutations then you are at higher risk. These are the men who should be encouraged to pursue screening and early detection.
Because if you catch prostate cancer early on—
Dr. Cheng: It is much more likely to be curable.
Anything on Mr. Dudley you want to share
Dr. Cheng: He has a family history of relatives with breast cancer diagnosed at an early age actually. One of his relatives was tested for BRCA 1 and 2 and found to be negative and it looks like this family might have a new gene that we’re studying right now. The family is enrolled and we’re trying to characterize gene better. But I think it’s an exciting time because we’re just learning about new genes that are important for prostate cancer risk as well.
He didn’t find it early on for him?
Dr Cheng: We did not find it early but since we were able to find it, he is on a clinical trial as a consequence of what we found and he is having a good response so far.
What are some of the new clinical trials that you were saying that kind of was parallel at the same time that this study came out?
Dr. Cheng: Prior to this study there was a study sequencing the DNA of prostate cancers that had spread outside the prostate. We found that many of those cancers had mutations in the same genes. That’s actually how we found Mr. Dudley and it’s as a consequence that we’ve enrolled him on a clinical trial that we think may specifically target his mutation. He’s on a clinical trial of a specific chemotherapy that we wouldn’t otherwise give him and he’s having a good response.
How does it make you feel personally when you’re able to make these new breakthroughs?
Dr. Cheng: It’s so exciting. This is why I do what I do. One of the things that is most rewarding is that in oncology, especially medical oncology, we often meet people later in their disease course when cancer is very treatable but it’s not curable. Being able to offer them more treatments that are more likely to be effective is really exciting. Also, having the possibility of preventing or detecting cancer earlier in their family members is something we don’t often get the opportunity to do. That makes it really fun to be involved in this research and patient care.
Can you tell me about metastatic and what does that mean?
Dr. Cheng: Prostate cancer is very common and most prostate cancer is not life threatening. But, occasionally it spreads outside of the prostate, when it may travel to distant lymph nodes or bone, and that is when it becomes metastatic and is unfortunately not curable but it is still very treatable.
Tell us again what was in your breakthrough, what did you guys learn?
Dr. Cheng: We found that in men with advanced, metastatic prostate cancer, over ten percent of them carry an inherited cancer risk mutation—we found these in both men with and men without a family history of cancer. This is important for treatment implications and is also important for family counseling.
As you said there is definitely more than just the BRCA 1 and 2.
Dr. Cheng: That’s right, the study had a panel of twenty genes and we found mutations in sixteen of them. These are known to be cancer risk genes largely from the breast and ovarian cancer literature but now we’re trying to study how much it affects prostate cancer risk.
How does this change treatment and you’re probably sharing this with doctors across the country.
Dr. Cheng: Yeah, it’s really exciting because we have a lot of good treatments and tools for prostate cancer but we’ve expanded them and we’re actively investigating new agents that we think will be especially effective for men who have these types of mutation.
What are the concerns of doctors who are not using this procedure and why aren’t they?
Dr. Cheng: These are brand new findings. It’s important to think about getting appropriate genetic counseling because the discussions can bring up a lot of mixed feelings on the part of patients and family members. I would really emphasize that it’s best to have discussions about testing with a genetic counselor, if possible.
Again the biggest take away is for men they need to talk to the—
Dr. Cheng: Men really should talk to their family about the family history of breast, ovarian cancers, and other cancers and share this information with their doctors, not just of prostate cancer. One of the things we found in the study is that a family history of non-prostate cancers may predict having one of these mutations better than a history of prostate cancer. That really says that we should be sharing this type of information with our family and our doctors. Genetic testing will become increasingly important to the care of prostate cancer patients, especially those with aggressive prostate cancer, and knowing one’s family history of cancer and other conditions is always helpful for best medical care.
END OF INTERVIEW
This information is intended for additional research purposes only. It is not to be used as a prescription or advice from Ivanhoe Broadcast News, Inc. or any medical professional interviewed. Ivanhoe Broadcast News, Inc. assumes no responsibility for the depth or accuracy of physician statements. Procedures or medicines apply to different people and medical factors; always consult your physician on medical matters.
If you would like more information, please contact:
Heather Cheng, MD, PhD
206-288-8300
prostategenetics@seattlecca.org
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