By Karuna Jaggar, Former Executive Director and SABCS Guest Writer
For people who want to have a biological child after breast cancer, there are a number of questions and concerns. Dr. Eva Blondeaux provided largely reassuring data about pregnancy in a paper presented on Thursday at the San Antonio Breast Cancer Symposium (SABCS): “Chances of pregnancy after breast cancer, reproductive and disease outcomes: a systematic review and meta-analysis” (GS3-09).
Dr. Blondeaux and her team conducted a meta-analysis of 39 studies, with more than 8 million women included in all. Of the well over 100,000 women with a history of breast cancer, 7,505 had a pregnancy after diagnosis.
The researchers compared women with a history of breast cancer with both the general population and with women with a history of other cancers. They wanted to know about:
- The chances of pregnancy after diagnosis
- Reproductive outcomes and pregnancy complications
- Maternal safety in terms of breast cancer recurrences and death
We’ve known for a long time that infertility is one of the enduring harms of breast cancer treatment and this study found that people treated for breast cancer had a 60% lower chance of becoming pregnant. Only women treated for cervical cancer had a lower chance of becoming pregnant. However, for those who were able to become pregnant, the results are largely reassuring.
Overall, there were some differences in reproductive outcomes for people who had been treated for breast cancer, but importantly, there was no sign of any congenital abnormalities. Women with a history of breast cancer were 14% more likely to have a caesarean section. Babies were more likely to be small for gestational age, preterm (45% greater risk), and low birth weight (50% greater risk). Complications were higher for women who had had chemotherapy.
Another positive finding was that pregnancy did not impact the risk of recurrence or death after breast cancer—if anything there was a small trend suggesting maybe women who got pregnancy did a little better. Researchers looked at a range of subgroups and found no evidence of any negative impact of pregnancy on breast-cancer related health regardless of: hormone receptor status, nodal involvement, BRCA mutation status, or history of chemotherapy. There was also no difference between women who had an abortion and those who gave birth.
Other areas of future research include the safety of interrupting treatment to get pregnant. Women have taken breaks from hormone therapy in order to conceive for years, and a study in progress will look at this, hoping to build on the evidence that post-treatment pregnancy does not lead to worse breast cancer outcomes.
“There is life after cancer” says Dr. Blondeaux—and apparently birth too!