Treatments and drugs

By Mayo Clinic Staff

A number of factors, including your personal preferences, come into play when you decide whether to undergo treatment for lobular carcinoma in situ (LCIS).

There are three main approaches to treatment:

  • Careful observation
  • Taking a medication to reduce cancer risk (chemoprevention)
  • Surgery


If you've been diagnosed with LCIS, your doctor may recommend more frequent exams to closely monitor your breasts for signs of cancer. This may include:

  • Frequent breast self-exams to develop breast familiarity and to detect any unusual breast changes
  • Clinical breast exams at least twice a year
  • Screening mammograms every year
  • Other imaging techniques, such as MRI, if you have other risk factors and a strong family history of breast cancer

Preventive therapy

Preventive therapy (chemoprevention) involves taking a medication to reduce your risk of breast cancer.

Two selective estrogen receptor modulator (SERM) drugs are approved to reduce the risk of invasive breast cancer. Both drugs work by blocking breast tissue's receptivity to estrogen, which influences the development and growth of many breast tumors.

  • Tamoxifen. Tamoxifen reduces the risk of developing invasive breast cancer. Tamoxifen can be used by both premenopausal and postmenopausal women. Tamoxifen is typically taken for five years.

    Tamoxifen slightly increases the risk of serious conditions including uterine cancer, stroke and cataracts, as well as side effects such as hot flashes and vaginal dryness. Tamoxifen also increases the risk of blood clots in postmenopausal women.

  • Raloxifene (Evista). Raloxifene is also approved to reduce the risk of invasive breast cancer in high-risk postmenopausal women, including those with LCIS. Raloxifene is as effective as tamoxifen in reducing risk of invasive breast cancer in postmenopausal women only. Raloxifene is linked to fewer cases of uterine cancer, blood clots and stroke than is tamoxifen, but is otherwise associated with similar health risks.

In general, these medications can reduce the risk of breast cancer by half.

Women who have multiple risk factors for heart disease or have a history of heart disease should not take either tamoxifen or raloxifene because of an increased risk of a stroke.

Another option for certain women may be exemestane (Aromasin), which decreases production of estrogen in the body.

Discuss with your doctor the risks and benefits of taking a drug for breast cancer prevention to see if it's the best course of treatment for you.


Surgery to remove the area of LCIS is another option for women who have an increased risk of breast cancer due to their family history of the disease. Removal is sometimes done at the time of a biopsy, but sometimes more tissue needs to be removed. After the LCIS is removed, you will continue to receive follow-up examinations, since you will still have a higher risk of developing breast cancer.

Another option for treating LCIS is preventive (prophylactic) mastectomy. This surgery removes both breasts — not just the breast affected with LCIS — to reduce your risk of developing invasive breast cancer. To obtain the best possible protective benefit from this surgery, both breasts are removed, because LCIS increases your risk of developing breast cancer in either breast.

Preventive surgery may be an option for you if you're at high risk of breast cancer based on a very strong family history or a BRCA gene mutation.

Surgery to treat LCIS isn't urgent, so you have time to carefully weigh the pros and cons of preventive mastectomy with your doctor.

Clinical trials

If you have LCIS, you might consider participating in a clinical trial exploring an emerging therapy for preventing breast cancer. Ask your doctor whether you might be a candidate for current clinical trials.

Aug. 15, 2014