LCIS does not require treatment in the way you might normally think of cancer treatment, such as needing to have surgery, radiation therapy, and chemotherapy. You and your doctor may decide that you should undergo careful observation to watch for any signs of invasive breast cancer. You also may decide to use strategies to reduce your risk of breast cancer in the future, such as medications or surgery.
Careful observation means sticking to a schedule of breast exams and screenings agreed upon by you and your doctor. The goal is to watch for signs of invasive breast cancer — and if signs do become evident, to act on them early. Your schedule may include the following:
- frequent breast self-exams to become familiar with your breasts and detect any unusual breast changes. Ask your doctor to show you the correct technique and how often you should examine your own breasts.
- clinical breast exams (manual exams performed by your doctor) at least twice a year
- screening mammograms every year
- possibly other imaging techniques, such as magnetic resonance imaging (MRI), if you have other risk factors for breast cancer and/or a strong family history of the disease
Hormonal therapy medicines such as tamoxifen, Evista (chemical name: raloxifene), and Aromasin (chemical name: exemestane) have been shown to reduce breast cancer risk. LCIS is usually hormone receptor-positive, meaning that estrogen and/or progesterone fuels the growth of the abnormal cells. If you decide to use medicine to manage your risk of breast cancer, you are likely to use tamoxifen, Evista, or Aromasin.
If you are premenopausal, your doctor is likely to recommend that you take tamoxifen, a medicine that blocks estrogen from attaching to the cells and signaling them to grow. Tamoxifen works to reduce the risk of an invasive breast cancer from developing in the future. A large clinical trial called The Breast Cancer Prevention Trial found that women with LCIS who took tamoxifen for 5 years reduced their risk of invasive breast cancer by 46%.
If you’ve already been through menopause, your doctor may suggest tamoxifen or Evista, another medicine that blocks estrogen’s effects on breast tissue. A large clinical trial known as the Study of Tamoxifen and Raloxifene (or STAR trial) showed that raloxifene was as effective as tamoxifen in reducing the risk of invasive cancer in postmenopausal women with LCIS.
Research published in 2011 showed that Aromasin can lower risk in high-risk, postmenopausal women who've never been diagnosed with breast cancer. Aromasin is not approved by the FDA for this use, but doctors may consider it a good alternative to tamoxifen or Evista. In 2013, the American Society of Clinical Oncology (ASCO) released new guidelines on using hormonal therapy medicines to reduce breast cancer risk in high-risk women. These guidelines recommend that doctors talk to high-risk postmenopausal women about using Aromasin to reduce risk. ASCO is a national organization of oncologists and other cancer care providers. ASCO guidelines give doctors recommendations for treatments that are supported by much credible research and experience.
Risk-reducing surgery, also called prophylactic mastectomy, is the removal of both breasts to reduce the risk of breast cancer ever developing. If you have other risk factors for breast cancer besides LCIS, such as a BRCA1 or BRCA2 mutation or a strong family history of the disease, you and your doctor might discuss this option. Prophylactic mastectomy would involve both breasts because LCIS, like these other risk factors, increases the risk of developing cancer in both breasts.
Keep in mind that LCIS is not an immediate threat to your health. You have the time to consult with your doctor and weigh all the pros and cons of risk-reducing surgery.
Yet another option is to take part in a clinical trial that is testing a new approach to reducing the risk of breast cancer. You can talk with your doctor about any clinical trials that may be available in your area.