CHEMOPREVENTION FOR BREAST CANCER APPROVED IN BRITAIN 

Chemoprevention of breast cancer with tamoxifen and raloxifene is recommended for women in England and Wales who have a high risk for breast cancer in an updated guidelinefrom the National Institute of Clinical Excellence (NICE). The chemoprevention recommendation is one of several recommendations in the updated guideline, which was issued after the draft guideline, published in January, underwent a consultation period.

Chemoprevention with tamoxifen and raloxifene is also recommended for women at highest risk for breast cancer by the US Preventive Services Task Force (USPSTF). After a systemic review published in the Annals of Internal Medicinefound evidence of broad benefit for chemoprevention (2013;158:604-614), it appeared in the USPSTF draft recommendations published in April.

Evidence-based Advice

The updated NICE guideline offers evidence-based advice on the classification and care of people at risk for familial breast cancer and on the management of people with a diagnosis of breast cancer and a family history of breast, ovarian, or related cancer. Many of these individuals carry a BRCA1, BRCA2, orTP53 gene mutation, or have a rare condition that carries an increased risk for breast cancer, such as Peutz–Jeghers syndrome (with a STK11 mutation), Cowden syndrome (with aPTEN mutation), and familial diffuse gastric cancer (with a E-Cadherin mutation).

In addition to chemoprevention, the guideline also discusses genetic testing, surveillance with annual mammography and MRI scans, and the option of prophylactic mastectomy.

It is the use of drugs to prevent the disease that has made headlines and been widely reported in the media. Although both drugs are available, they are not approved for chemoprevention in the United Kingdom; tamoxifen is indicated to prevent a recurrence in women who have already had breast cancer, and raloxifene is licensed for use in osteoporosis. When physicians now recommended these drugs for the prevention of breast cancer in women who are at high risk for the disease, the use will be off-label. (They are, however, approved for chemoprevention in the United States.)

"The prescriber should follow relevant professional guidance, taking full responsibility for the decision," according to the NICE guideline. "Informed consent should be obtained and documented."

Both drugs are equally effective in preventing breast cancer, and they can reduce a person's risk by 30% to 40%, it reports.

The guideline recommends that either tamoxifen or raloxifene be offered for 5 years to postmenopausal women with a uterus and a high risk for breast cancer, unless they have a history of or are at increased risk for thromboembolic disease or endometrial cancer.

In addition, tamoxifen has been shown to be effective in premenopausal women.

Offering these drugs could help prevent breast cancer in around 3% of all women 35 years and older — which is an estimated 488,000 women, the guideline points out.

Clinical evidence shows that these drugs are an effective option for many women and could be preferable to surgery, said Prof. Mark Barber, director of clinical practice at NICE.

"This is a truly historic moment in the treatment of women at increased risk for breast cancer, as we are witnessing a fundamental change of clinical practice driven by medical research," said Baroness Delyth Morgan, chief executive officer of Breast Cancer Campaign.

"The whole guideline is a major move forward, in that more women than ever before face the possibility of doing something tangible to reduce their risk of breast cancer," said Gareth Evans, MBBS, MD, FRCP, consultant in clinical genetics at St. Mary's Hospital in Manchester, United Kingdom, and a member of the Guideline Development Group.