ASCO 2017: Safety of Pregnancy After Breast Cancer
By: Meg Barbor, MPH
Posted: Monday, June 5, 2017
Pregnancy after breast cancer does not seem to increase the chance of recurrence or death, according to data from a long-term follow-up analysis of more than 1,200 female breast cancer survivors with a history of estrogen receptor–positive disease, presented by Matteo Lambertini, MD, and colleagues, at the 2017 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract LBA10066).
“Our findings confirm that pregnancy after breast cancer should not be discouraged, even for women with [estrogen receptor]–positive cancer,” said Dr. Lambertini, a medical oncologist at the Institut Jules Bordet in Brussels, Belgium.
Because estrogen receptor–positive breast cancer is fueled by estrogen, physicians and patients have long been concerned that the hormones released during pregnancy could increase the chance of cancer recurrence. Previously, the investigators showed no detrimental effect of pregnancy on breast cancer outcome within 5 years following conception, but the new long-term data offer further encouragement for breast cancer survivors considering pregnancy.
In the study, 333 patients with pregnancy after breast cancer were matched with 874 patients without subsequent pregnancy, and the majority (57%) of patients had estrogen receptor–positive breast cancer. After 12.5 years from conception, the researchers observed no difference in disease-free survival or overall survival between pregnant and nonpregnant patients with estrogen receptor–positive disease.