(HealthDay News) — Women who have been diagnosed with estrogen receptor (ER)-positive breast cancer can safely become pregnant without increasing the risk of recurrence, according to a study presented at the annual European Breast Cancer Conference, held from March 21 to 24 in Vienna.
Hatem A. Azim Jr., M.D., from the Institut Jules Bordet in Brussels, and colleagues examined whether ER status affected breast cancer recurrence with pregnancy in 333 women who had become pregnant after being diagnosed with breast cancer and 874 matched breast cancer patients who did not become pregnant. Women in the control group had not relapsed at the time the matched case became pregnant. Overall, 57 percent of women were ER positive.
At an average of 4.7 years after pregnancy, the researchers found that breast cancer recurred in 30 percent of women overall. Disease-free survival was similar regardless of ER status. Patients who became pregnant within two years of a breast cancer diagnosis appeared to have improved disease-free survival, though a clear trend over time was not observed. Abortion (spontaneous or induced) had no effect on breast cancer recurrence, regardless of ER status.
“The study is statistically powered to confirm that pregnancy is safe and should not be discouraged following breast cancer diagnosis, irrespective of ER status,” Azim and colleagues conclude.