According to American Cancer Society, breast cancer is the most common cancer in women except for skin cancers. The average risk for a women developing breast cancer in her lifetime is 12 percent (1 of out 8). How do you know if you're at risk or have a greater chance for developing breast cancer? 

Michael Cassidy, MD shares risk factors for breast cancer you should know about.

Featured Speaker:

Are You at Risk for Developing Breast Cancer?

Michael Cassidy, MD

Michael Cassidy, MD is a surgical oncologist specializing in breast cancer. Dr. Cassidy completed his medical school training at Boston University School of Medicine. Prior to joining the team at Boston Medical Center he completed a fellowship in complex general surgical oncology at Memorial Sloan Kettering Cancer Center.


Melanie Cole: If one of your close relatives has been diagnosed with breast cancer, you may have concerns or start wondering whether breast cancer runs in your family. My guest is Dr. Michael Cassidy. He's a surgical oncologist at Boston Medical Center. When we look at risks for breast cancer, what role does inherited trait play in developing breast cancer?

Dr. Michael Cassidy: If you look at average risk for breast cancer, the average lifetime risk for a woman in the United States is about 12 percent, meaning about one in 8 women in their lifetime will be diagnosed with breast cancer. The majority of breast cancers we consider to be sporadic, meaning they don't have a link to a known gene mutation, however, in the smaller percentage of breast cancers, they are associated with an inherited gene mutation and we consider those to be patients who are at an increased risk for both breast cancer and ovarian cancer and some other cancers.

Melanie: When we've heard about this gene, the BRCA gene 1 and 2, tell us what those are and please explain if all women contain these genes because there is some confusion if you have the gene, but it's really a mutation of this gene. Give us a little lesson about it.

Dr. Cassidy: The BRCA 1 and 2 genes are the most common gene mutations that are associated with an inherited risk for breast cancer. You can inherit that gene mutation from either your father or your mother. If you have inherited that gene mutation, it gives you about a 60% lifetime risk of breast cancer and about a 40% risk of ovarian cancer.

Melanie: These mutations of these genes, are they more common in certain racial and ethnic populations than others?

Dr. Cassidy: They are more common in patients who have an Ashkenazi-Jewish background.

Melanie: Who should get tested then? That's the big question and we'll get into what you do with the information, but who should get tested for this genetic mutation? How early in life? When?

Dr. Cassidy: We can think about it in two ways. We can think about patients who have no personal history of cancer and those that do have a personal history of cancer. For patients with a known breast cancer, any patient who is younger than the age of 50 at their diagnosis of breast cancer should consider genetic counseling and genetic testing. Patients who have a subtype of breast cancer, which is known as triple negative breast cancer, at an age before 60 years should consider genetic testing. Any man with breast cancer should consider genetic testing.

Patients who have breast cancer and have had a relative with breast cancer before the age of 50, have had a relative with ovarian cancer, have had two relatives with a mix of cancer that includes breast, prostate, and pancreas, or anyone with a relative who has a known gene mutation in the family.

For patients who have no personal history of breast cancer, we think about some of those same things.Blood relatives with known gene mutations, blood relatives who have had two or more breast cancers in the same relatives, at least two relatives on the same side of the family with a cancer, one of whom was diagnosed before the age of 50, blood relatives with ovarian cancer or male breast cancer.

Melanie: Let's talk about some of the practical aspects of genetic testing. It has to go together with counseling, so what do you tell patients about getting this test and how they should interpret the results. What do they do with this information?

Dr. Cassidy: Here at Boston Medical Center, we have a genetic counselor who meets with patients who we suspect may be at higher risk for having a gene mutation predisposing them to cancer, and our genetics counselor takes a very detailed family history and looks at a number of factors, and then talks about the process of the actual genetic testing and how to interpret the results. The actual testing itself is a simple blood test that's sent off to a lab and that test is not only for BRCA 1 and 2, which are the most common but the blood test also looks for a number of other rarer gene mutations as well.

When the results come back, we either can find a gene mutation, we can say there's no gene mutation identified or we can say that there is a gene mutation in one of these genes that is of undetermined significance, meaning we don't really understand the implication of it.

Melanie: What are some of the limitations to genetic testing and some of the possible harms of getting this test when they have to really come up with some life-altering decisions about preventive surgery or possible infertility or early menopause, all of these things – what do you tell people?

Dr. Cassidy: The first limitation is that we can't necessarily identify all gene mutations that may be associated with inherited risk for cancer. We know about some, but there are likely others that we don't know about and that we can't test for, but still made patients at risk for cancer. It can be a little bit difficult to interpret. Finding out you have a gene mutation also brings up a number of questions in terms of what to do about managing that risk, so patients really have to think about what they would do with the information if they were to receive it and be prepared to make some decisions about that.

Melanie: Some of those are pretty big decisions. How does genetic counseling help them to determine that risk and make those decisions?

Dr. Cassidy: The genetic counselor is really an expert in risk assessment and also in helping patients to decide if they are prepared to receive these results and prepare to make decisions about them. That's a very important clinical encounter where the genetic counselor really takes a lot of time with the patients and talks to them about these very complicated issues. They're often difficult to understand and so the genetic counseling process is very important in terms of making sure patients understand as much as they can about the process and possible results.

Melanie: One of the big concerns that many people have that are considering genetic testing is insurance discrimination. First of all, does insurance pay for this kind of a test, and what happens if the results come back positive? Is this something now that will follow you through life and you could be turned down for certain insurances?

Dr. Cassidy: There's been a lot of talk about that, and for the most part, insurance should pay for that. We work with patients to make sure that's true ahead of time and we have other resources available, so it should not be an insurance issue.

Melanie: In summary, what would you like women to know about breast cancer awareness, the latest advancements in genetic testing and asking the right questions, being their own best health advocate?

Dr. Cassidy: The majority of women will be at what we consider the average risk for breast cancer,meaning that the lifetime risk in the United States is about 12%. The most important thing is to keep up with screening mammograms. For average-risk women, that is the best strategy. For women who may be at increased risk, meaning they have a family history of breast cancer, particularly family history and relatives who have had breast cancer at a younger age, it's an important topic to raise with your physician who can really calculate the risk and determine if a referral for genetic counseling and testing would be important. 

There are a number of risk-reducing strategies that are available to patients who may be found to have a gene mutation, so even in those patients who we do identify as being at very high risk for breast or ovarian cancer, we have strategies that are more effective the earlier we can implement them. Thinking about this early and raising this as a discussion point with your doctor is important.

Melanie: Thank you so much for being with us today and sharing your expertise on this very importan ttopic. This is Boston MedTalks with Boston Medical Center. For more information, you can go to That's This is Melanie Cole. Thanks so much for listening.