By David Liu, PHD

Friday Oct 19, 2012 (foodconsumer.org) -- A review in Cochrance Database Systemic Reviews found evidence to suggest that using tamoxifen after surgery helps prevent recurrence of ductal carcinoma in situ, a non-invasive breast cancer, but not reduce the overall death risk.

H. Staley at North Tyneside General Hospital in North Shields, Tyne & Wear, UK and colleagues conducted the review found the disappointing evidence.

Ductal carcinoma in situ (DCIS) has been seen on the rise over the last twenty years, largely because of use of the population-based mammographic screening for breast cancer, according to the reviewers.

Patients with DCIS tumours often receive surgery with or without radiotherapy to prevent recurrence of the disease and invasive breast cancer.   But doctors often also ask patients to take tamoxifen after surgery in hopes that this hormonal therapy can prevent recurrence and increase overall survival. 

The researchers searched major medical databases for published and unpublished randomized controlled trials and quasi-randomized controlled trials on tamoxifen use and outcomes of the breast cancer treatment.

In two trials of 3375 women with the non-invasive breast cancer, tamoxifen treatment after breast cancer surgery did reduce recurrence of both ipsilateral ductal carcinoma in situ by 25 percent and contralateral ductal carcinoma in situ by 50 percent.  And the treatment also reduce contralateral invasive breast cancer by 43 percent.

However, tamoxifen use did not reduce the all cause death risk or mortality.  Tamoxifen use was also associated in one 163-month follow-up study with increased chance of developing endometrial cancer.

The reviewers concluded "While tamoxifen after local excision for DCIS (with or without adjuvant radiotherapy) reduced the risk of recurrent DCIS (in the ipsi- and contralateral breast), it did not reduce the risk of overall mortality."

Breast cancer is expected to be diagnosed in more than 230,000 women each year in the United States and the disease kills about 40,000 women annually in the U.S., according to the National Cancer Institute.