These data will help us personalize treatment for our patients. We still don’t know which women with a favorable cancer like ductal carcinoma in situ are most likely to progress. This is an unmet need,” said C. Kent Osborne, MD, Director of the Dan L. Duncan Cancer Center at Baylor College of Medicine in Houston. Dr. Osborne moderated the press conference at which both studies were discussed.

When asked why women with stage 0 breast cancer would want to take these drugs, Dr. Osborne said: “The risk of recurrence with ductal carcinoma in situ is 7% to 10% over the next 10 years. These drugs can reduce the local recurrence rate by half, so many women would opt for taking them. It is important to prevent recurrence of ductal carcinoma in situ, because when it happens in the same breast, patients will require a mastectomy,” he continued.

“Atypical hyperplasia carries a 25% risk of breast cancer over a lifetime. Many of these women would also opt for a hormonal agent,” he stated.

“These data suggest that an aromatase inhibitor may be a little better in a postmenopausal woman under age 60 if you think the risk of recurrence is increased, but if sexual function is a problem, you can switch to tamoxifen. The drugs are almost interchangeable,” continued Dr. Osborne. “I would start an older women on tamoxifen, unless she had a history of thrombotic events,” he added. ■

Disclosure: Dr. Osborne has served on advisory boards for AstraZeneca, Genentech, Pfizer, and NanoString.