Doctor Weighs In On Breast Cancer Study
MELISSA BLOCK, host:
And now to someone who helps women make those decisions. Dr. Kenneth Offit is chief of the Clinical Genetics Service at Memorial Sloan-Kettering Cancer Center in New York. Dr. Offit, welcome to the program.
Dr. KENNETH OFFIT (Chief, Clinical Genetics Service, Memorial Sloan-Kettering Cancer Center): Thanks.
BLOCK: And will this new study, do you think, change how you counsel your patients who do test for these genetic mutations, who do have the mutations?
Dr. OFFIT: Well, so we published a similar study eight years ago at Sloan-Kettering based on our experience. And at that time, people said that the surgery options were too drastic. Now, we have this report today from 20 centers, and this confirms powerfully that genetic testing as well as surgery together are a powerful strategy to prevent breast and ovarian cancer.
BLOCK: So more data for women to think about if they're considering having surgery, do you think this bolsters the case for going ahead and having the surgery?
Dr. OFFIT: I think yeah. It's very persuasive data. You still have to keep in mind if you look at this paper that still 90 percent of the women, even in this study, opted not to have the breast surgery, so it's still a very difficult decision. The breast decision is one which is highly personalized.
The ovarian surgery is one which we feel much more strongly about. Here, only 40 percent of the women in the study opted for it. At Sloan-Kettering, we are aiming more to 80 percent, and that's because we really don't have any means to screen for ovarian cancers, which we do have for breast cancer.
BLOCK: So in other words you feel more strongly about it meaning you would counsel it because the screening for ovarian cancer is not great.
Dr. OFFIT: Exactly right. We don't have a screening test for ovarian cancer, and most ovarian cancers will present at an advanced stage. We call it stage three and four. In fact, the only really early stage of ovarian cancers I saw at Sloan-Kettering after a decade were - occurred after we started doing this type of BRCA testing.
We found that when we did the preventive ovarian surgery, three percent of the time we did a preventive surgery, we would find a microscopic small and curable ovarian cancer. And this is I think a very powerful argument to be going ahead and doing this laparoscopic surgery. It's not difficult surgery to have.
BLOCK: Mm-hmm. How common are these mutations, Dr. Offit?
Dr. OFFIT: The mutations aren't terribly common. We think probably one in 400 women in the general population. But there are some populations in the world -I actually describe the most common mutation of BRCA2 and that occurs in individuals of Eastern European Jewish ancestry, Ashkenazi Jews.
And in the Eastern European Jewish group and also in some other groups, such as those in Iceland, we have very high rates. In the Jewish group, for example, one in 40 individuals, not one in 400, will carry a BRCA mutations.
BLOCK: Mm-hmm. When you're counseling women on possible surgery, how do you factor in the age of the patient and the age of potential onset of the disease? I mean, a younger woman might want to know, look, am I at risk for cancer now, or were you talking about something that might happen when I'm 80?
Dr. OFFIT: And this is really I think the difficult issue because women are at their active phases just exactly when they need to have these surgeries. So the onset here for breast or ovarian cancer is much earlier. We're talking about the 30s or the 40s, and ovarian cancer by age 50. So we advise the ovarian surgery as soon as childbearing is completed.
BLOCK: And you would advise genetic testing too for men with strong family history?
Dr. OFFIT: Yes, that's right. For men who have a family history of breast or ovarian cancer, we also advise the genetic testing, and that's because the males, or the men, are particularly prone to developing prostate cancer.
We did a study earlier this year that showed that the men who develop prostate cancer will develop it sometimes in a more aggressive form. So if you're a man and your sister had breast cancer, your mother had ovarian cancer, you also need to have BRCA testing.
BLOCK: Okay, Dr. Offit, thank you very much for talking with us.
Dr. OFFIT: Thank you.
BLOCK: Dr. Kenneth Offit is chief of the Clinical Genetics Service at Memorial Sloan-Kettering Cancer Center in New York.
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