Investigators found that temporarily interrupting therapy did not raise the short-term risk of disease recurrence, and nearly 64% of women gave birth while therapy was paused. Clinical guidelines recommend adjuvant endocrine therapy for 5 to 10 years to reduce the risk of recur - rence following treatment for early- stage hormone receptor–positive breast cancer. Prior to this trial, there were little data on whether interrupting therapy to pursue pregnancy would increase the risk of relapse, which pre- sented a clinical dilemma for women in their prime childbearing years. “This is good news that is most relevant for women diagnosed with cancer before age 40 who may not have started a family or want to complete their families,” says the study’s lead author, Ann Partridge, MD, MPH, of Dana-Farber Cancer Institute in Bos- ton, MA. “We found that temporarily interrupting therapy for pregnancy did not worsen outcomes from any breast cancer events—including distant events, which are most concerning because they are not typically curable.” The trial followed 497 women age 42 or younger who had received adjuvant endocrine therapy for 18 to 30 months. In total, 74% of study participants had at least one pregnancy and 63.8% had at least one live birth. After a median of 3 years, the incidence of breast cancer was 8.9% in the treat- ment interruption group versus 9.2% in an external control group. Research- ers allowed for the possibility that the findings are biased by a “healthy mother” effect—meaning that women with a lower risk of recurrence were more likely than others to participate in the trial and become pregnant. “The results of the POSITIVE trial provide a framework with concrete recommendations and critical safety data to guide conversations with our patients about the short-term safety of interrupting endocrine therapy to pursue pregnancy,” says Jennifer Specht, MD, of Fred Hutchinson Cancer Center in Seattle, WA. “With this data, we can provide advice to pa- tients about the risks of breast cancer recurrence and important reassurance about pregnancy outcomes.”Downloaded from http://aacrjournals.org/cancerdiscovery/article-pdf/13/7/1504/3345622/1504.pdf by guest on 29 November 2024