Breast cancer is the most common cancer diagnosed in women, and second only to lung cancer in deaths per year in the US. About 250,000 new cases are diagnosed per year, with approximately 40,000 deaths. We know that 12% of women will be diagnosed with breast cancer in their lifetimes. No doubt, this is a disease that has touched us all one way or another.
Now there is some good news about breast cancer mortality.
In the recent publication CA: A Cancer Journal for Clinicians and its companion Breast Cancer Facts and Figures, it was noted that breast cancer mortality has decreased 40% from 1989 to 2015. This decrease translates into 322,000 lives saved over that period of time. This contrasts with an increase in breast cancer mortality from 1975 to 1989, where mortality increased about 0.4% per year.
So, what has changed during that period of time?
There have been many improvements in breast imaging in the last 20 years. Mammography has improved, with digital mammography and now tomosynthesis (3D imaging) adding to technical advances. Ten years ago it seems that most breast cancers were diagnosed that were larger than 1 cm in size. Now with tomosynthesis, many breast cancers are found that are less than 1 cm. When you think about the fact that a breast cancer is three dimensional, the difference between a 5 and 10 mm tumor is not half, it is much less. Less tumor volume translates into less invasion into nearby lymph and blood vessels. I believe we will continue to see decreases in mortality due to this recent technology.
Other advances are in treatment options. New forms of chemotherapy developed since the 1980's prevent metastases and recurrences. Tamoxifen, an anti-estrogen, was developed in the late 70's and is used to treat hormone sensitive breast cancer, and also for prevention in high-risk women. Aromatase inhibitors which prevents estrogen production in postmenopausal women also reduces recurrences. Herceptin treats breast cancers which contain a high level of HER2, a protein on breast cancer cells that is a growth factor which makes these tumors more aggressive.
More targeted therapies are currently being developed.
We have come a long way, but there is still a long way to go. Today's news, reported in the Washington Post, is very encouraging!!!
Marilyn C. Jerome, MD
Foxhall Ob-Gyn Associates
Washington Post, October 4, 2017. Study shows long-term drop in deaths from breast cancer