News release

Extending Tamoxifen Use Beneficial for Some Breast Cancer Survivors

Cancer Care Nova Scotia

Cancer Care Nova Scotia is recommending breast cancer survivors and their doctors discuss extending the use of the drug Tamoxifen from five to 10 years.

The recommendation comes in light of a new study showing a lower risk of breast cancer recurrence and improved survival for some patients. However, patients are advised there is also an increased risk for endometrial cancer, which is a gynecologic cancer, and blood clots by extending the use of the drug.

"Treatment decisions are never black and white, but information is key to making an informed decision," said Dr. Tallal Younis, medical oncologist and co-chair of Cancer Care Nova Scotia's Breast Cancer Site Team. "Choosing the 10 year treatment strategy should be based on an individual's personal risk of recurrence, previous tolerance of Tamoxifen and personal preference.

"I encourage women to speak with their family physician or other primary care provider and if need be, ask for a referral back to their oncologist for further discussion."

The results of the study, called the Adjuvant Tamoxifen Longer Against Shorter trial, were published in the medical journal, The Lancet, in December.

The trial included 12,894 women with early stage breast cancer who were close to completing five years of taking Tamoxifen following surgery, or who had completed the five year treatment course and could resume it with little interruption.

The women were randomly put into two groups. One group continued Tamoxifen for another five years and the other group received no further treatment.

Those who took Tamoxifen for 10 years had a 21.4 per cent chance of the cancer recurring. The group who only took the drug for five years had a 25.1 per cent chance of recurrence. Similarly, women who continued with Tamoxifen for 10 years had a 12.2 per cent risk of dying from the disease but women who took the drug for only five years had a 15 per cent risk of dying.

The study also indicated the extended use of Tamoxifen from the current five year standard following surgery to 10 years increases a woman's risk for endometrial cancer and pulmonary embolisms or sudden blockages in the lung as a result of a blood clot.

"I hope all breast cancer survivors will discuss the benefits of using Tamoxifen with their physicians. This drug may result in lower cancer recurrence and in improved survival," said David Wilson, Minister of Health and Wellness.

The Breast Cancer Site Team has sent a letter to all family physicians and surgeons, who care for women with breast cancer, informing them of this change in practice.

Cancer Care Nova Scotia's Breast Cancer Site team is one of 13 site teams, each specializing in one kind of cancer or cancer site. Membership is multidisciplinary including all manner of health professionals such as oncologists, nurses, pharmacists, surgeons, dieticians, social workers and others. Cancer Site Teams review care and develop evidence-based treatment guidelines to support consistent, high quality care.

Cancer Care Nova Scotia, a program of the Department of Health and Wellness, was created in 1998 to facilitate quality cancer prevention and care for all Nova Scotians.