Skip to Content

NorthShore’s online source for timely health and wellness news, inspiring patient stories and tips to lead a healthy life.

Healthy You

A Passion for Care: Dr. Katharine Yao on the Up Rise in Double Mastectomies

Wednesday, October 25, 2017 7:56 AM

Katharine Yao, MD, discusses the changes she has seen in her years of experience with breast surgery in the past decade. According to analysis of the National Cancer Data Base, double mastectomies accounted for 12% surgeries in women with Stages 0 to 3 breast cancer, which is up 2% from 1998. Dr. Yao’s analysis found that in the past year, almost 30% of women under the age of 45 chose to have both breasts removed. She shares what led her to medicine, her passion for care for her patients, as well as her insight on the analysis she has done.

What influenced you to go into medicine? Why did you choose oncology, and specifically breast surgery?
I chose breast surgery because I like the fact that we have made progress in this area. The research in breast cancer translates into real changes in the clinic. It is very gratifying to know you are making a difference for patients by being involved in important research studies.

What have been the biggest changes, trends and discoveries in the field of breast cancer since you have been practicing medicine?
I think one of the biggest changes in breast cancer over the past decade is that we have learned how heterogeneous or diverse breast cancer can be. We have learned how to categorize breast cancer into different subtypes based on tumor markers and these subtypes are prognostic as well. Moreover, we have therapies that target these specific subtypes and these therapies have really improved breast cancer survival for women who were once put into a poor prognostic category.

In the field of breast surgery, we continue to demonstrate that we can minimize the amount of surgery for many patients. This lessens morbidity from surgery and its after effects particularly with respect to axillary (pertaining o the armpit) surgery. We used to remove all the nodes in the axilla for newly diagnosed breast cancer patients, but now we can just remove a couple of nodes even for patients that have tumor in their nodes.

Another area that has exploded in breast cancer is genetic testing. We have much more knowledge about genetic mutations that predispose to breast and ovarian cancer, and we now can test for many more genes. Genetic testing for BRCA has become commonplace with much faster turnaround thereby allowing patients to use the information for surgical decision making.

According to your analysis of the National Cancer Data Base, more and more women are electing to have double mastectomies for Stages 0 to 3 breast cancer. What factors do you think contribute to this rise?
Many reasons contribute to this rise including external factors such as greater access to reconstructive surgery, more preoperative testing such as breast MRI, more awareness of family history and genetic testing, and more awareness of options for breast cancer treatment in general. However, the most common reasons are based on patient’s misperceptions about bilateral mastectomy (surgery that removes both breasts). Most studies have shown that the two most common reasons that patients choose to remove both breasts – know as Contralateral Prophylactic Mastectomy (CPM) – is to improve their survival but, CPM has not been shown to improve survival and to decrease their risk of a contralateral cancer. Women often overestimate their contralateral risk at 30-40% when in reality it is closer to 5%.

What led you to do this analysis?
In my clinic I was seeing that more and more women, particularly younger women, were requesting bilateral mastectomy. At the time we were a beta test site for the National Cancer Data Base participant user file and we started to look at the rates of bilateral mastectomy and saw a dramatic increase.

What were the key findings of your research? Did anything stand out to you specifically? Or surprise you?
I was surprised to see such a dramatic increase over the past decade particularly amongst younger women despite the fact that no clinical trials or large studies were published that showed that bilateral mastectomy was superior to unilateral mastectomy (surgery that removes one breast) or lumpectomy. Our research has shown that age is the most significant factor related to bilateral mastectomy but we still see increasing rates across all tumor types, patient races, facility types, tumor stages and regions of the country.

Did you find that the national trends reflected what you were seeing in your practice at NorthShore?
Yes, our trends here at NorthShore mirror what we have seen nationally.

What is your advice to patients recently diagnosed with breast cancer who may be considering a double mastectomy?
I always try to inform my patients about their low risk of a contralateral breast cancer and that contralateral breast cancer is usually a new primary breast cancer, not spread from the original cancer. I also explain that survival is dictated by the cancer’s ability to spread to distant sites and the tumor will do this whether a patient has a bilateral mastectomy or lumpectomy, tumor biology dictates distant spread, not the type of surgery. This is why bilateral mastectomy does not change survival. I also inform patients about the risks of bilateral mastectomy –it has twice the operative complications of a unilateral mastectomy. That being said, after hearing all of this some patients will still opt to have a bilateral mastectomy which I am fine with, I just want to make sure patients are making well informed decisions. I am in the midst of working with colleagues at Mayo, MD Anderson, UCSF and Dana Farber to create a decision tool that surgeons can use with patients to guide them through these difficult decisions.

What does the future hold for breast cancer prevention, diagnosis and treatment? What are you personally most excited about?
I am excited about new targeted therapies for the more aggressive forms of breast cancer which many researchers are looking into. We are also moving towards not only individualizing treatment for newly diagnosed patients but individualizing how we assess risk on patients and how we should screen patients. We have some exciting new studies looking at using a genetic risk score to better assess risk and to determine who really benefits from a screening mammogram versus some other screening modality.