Hereditary cancer syndromes cause a significant portion of gynecologic malignancies. Many times, gynecologic cancers are diagnosed in the late stages, at a time when treatment options are limited.
Hereditary cancer risk assessments are key in identifying patients and families who may be at increased risk of developing hereditary gynecologic cancer syndromes, such as breast and ovarian cancer syndrome, Lynch syndrome, Li–Fraumeni syndrome, Cowden syndrome, Peutz–Jeghers syndrome, and hereditary diffuse gastric cancer.
This short video—brought to you by Christina Chu, MD, Interim Chief, Division of Gynecologic Oncology and Professor, Department of Surgical Oncology at Fox Chase—provides an overview of hereditary gynecologic cancer syndromes and when to consider referring a patient for genetic counseling.
My name is Kristina Chew and I'm one of the G by oncologists here at Fox Chase Cancer Center. And today I want to talk with you a little bit about hereditary gynecologic cancer syndromes. And when you might want to consider referring patients for genetic counseling, We'll start off with hereditary ovarian cancer. Now only about 10% of ovarian cancer is hereditary. But we spend a lot of time thinking about those patients because we know that we don't have any good screening for ovarian cancer and most patients are diagnosed with late stage disease. It becomes really important to be able to find these patients upfront before they suffer from the disease. As most of, you know, the majority of hereditary ovarian cancer is caused by mutations in the B. R. C. A one and two gene. And as you can see from the figure, about half of hereditary cases are due to mutations and B. R. C. A one which confers a lifetime risk of ovarian cancer of about 40% and up to a 70% risk for breast cancer. B R C A two is responsible for another quarter and then a bunch of other important syndromes and gene mutations are responsible for the rest. You may be most familiar with lynch syndrome, which we'll talk about a little later but some other important syndromes, including mutations in TP 53 which is leave Romania syndrome, STK 11 which has put swagger syndrome, P. 10, which is the Hammer toma tumor syndrome. CDH one, the hereditary diffuse gastric cancer syndrome and then paul B to some other important moderate Pederson genes include NF 1 80 M. Check to Bard one Group one rad 51 C. Or D. In my career I've taken care of patients from almost all of these families and they have a lot of different types of cancer. So they can be important individuals in your practice. So who needs genetic counseling for ovarian cancer risk? There's a very long list of people who might benefit from genetic counseling. And if you can identify patients in a leaf Romania family and it puts a bigger family of course those patients merit genetic testing. Otherwise our examination of a patient's risk has to do with their family history. The CDC has put together a nice list of recommendations and they center around um breast cancer and ovarian cancer history. So if a patient has at least one family member with Breast cancer diagnosed under the age of 45 young breast cancer, a family member diagnosed with triple negative breast cancer which is estrogen receptor negative, progesterone receptor negative and her two negative under the age of 60 a single family member with bilateral breast cancer, one who's had both breast and ovarian cancer, even one with just with ovarian cancer or a male relative with breast cancer, all of those patients would merit a referral for genetic counseling and testing. Now if somebody has at least two relatives diagnosed with breast cancer. If at least one was diagnosed at the age of 50 you could consider referring that patient as well. And anyone with at least three relatives from the same side of the family with breast cancer or high grade prostate cancer at any age merits uh referral protesting a little bit about hereditary and demetrius cancer. Mhm. In this case we're talking mostly about lynch syndrome. Now, lynch syndrome is not just one gene mutation, it's due to mutations in a group of genes called the DNA mismatch repair genes or the MMR genes. And the most common are M. L. H. One, M S. H two, M. S. H six and PMS two. This is the most common cause of inherited colorectal cancers. But if you look in families, women in these lynch families often have a higher rate of endometrial cancer than they even do have colon cancer. So it's something really important in your practice to um to check on now in the lynch syndrome, of course there is right sided colon cancer but other cancers including endometrial cancer, ovarian cancer, stomach, small bowel, pancreas, bladder, brain, skin and prostate cancer. Now, About one in 200 people in the population has lynch syndrome. So this is something that's very common. Anyone who's had surgery for colon cancer or endometrial cancer will have their cancer screened for lynch syndrome. However, if you're not someone who suffered from one of these cancers. We're again, we're talking focusing on family history. The most common criteria that we used to look to see whether someone merit counseling or the Amsterdam criteria. And this is the 3-1 rule. So three relatives with Lynch cancers. Um two generations of winch cancers Or one young cancer. One of these cancers diagnosed at the age of 15. Any of these patients who fulfill one of these criteria should be referred for genetic counseling. Now, genetic counseling and testing. I've used that term counseling a lot today. Why is counseling important and not just testing? I think it's fair to say that the vast majority of medical societies and medical guidelines that are published on the topic recommend genetic counseling is part of a comprehensive genetic risk assessment. First of all, it's really important before testing occurs for patients to have true informed consent so they understand what the risks and benefits of genetic testing are. I think genetic counselors are well equipped to do comprehensive counseling, evaluate psycho, social and ethical issues and they're in a good position to discuss with the patient whether they would like to have a panel test which includes many of the genes and many others that we talked about earlier versus just single site testing. Just mutation testing for B. R. C. A one and two for example. Um And some patients will benefit from a panel test and occasional patients will benefit just from a single site testing. It depends on the situation. I do want to say a word about direct consumer testing. Of course many of our patients these days are swapping themselves and ordering tests like 23 me, they 23 Me does offer testing for BRC one and two. It's really important to note that that test only covers three of the founder mutations for BRC one and two when we know that there are a plethora of pathogenic mutations that are not covered by that test. So the patient says that they have a negative test for B. R. C. A. Based on 23 me that's not reliable because it would only cover three mutations. I think the last reason that comprehensive genetic counseling is important is post test counseling. It's important to know what a negative test really means. Is that informative? Is it not informative? It's important for patients to know how they might want to approach their family members who might be affected. It's also important for them to think about themselves about their cancer risk and what they're modifications to routine genetic screening or routine cancer screening might look like. So, I hope this has been a good summary for you of what we look for is going to college is for patients with ovarian cancer risk. And while you might consider a referral for counseling as well as just testing. Thank you very much