It’s estimated that there are about 400,000 breast cancer survivors younger than 45 in the United States. Many of these women might want to have children, but some doctors have been concerned that getting pregnant after a breast cancer diagnosis might affect the risk of breast cancer coming back (recurrence). This is because hormones can promote the growth and spread of breast cancer, and during pregnancy, hormone levels change.
Many women who get pregnant after a breast cancer diagnosis end their pregnancies because they’ve been told it would reduce their risk of recurrence, especially if they had been diagnosed with hormone-receptor-positive breast cancer and got pregnant within 5 years after diagnosis – getting pregnant would have meant their hormone therapy treatment would have been interrupted.
A study suggests that women who get pregnant after being diagnosed with breast cancer have the same recurrence risk as women who don’t get pregnant after being diagnosed, no matter the hormone-receptor status of the breast cancer.
The research was published online on Nov. 19, 2012 by the Journal of Clinical Oncology. Read the abstract of “Prognostic Impact of Pregnancy After Breast Cancer According to Estrogen Receptor Status: A Multicenter Retrospective Study.”
The study matched 333 women who became pregnant any time after a breast cancer diagnosis with 874 similar women who didn’t get pregnant after diagnosis. The women were similar in terms of:
- cancer hormone-receptor status
- number of lymph nodes involved
- type of treatment(s) after surgery
- year of diagnosis
The researchers found that there was no difference in the risk of recurrence between the two groups of women. Even when the researchers looked at only women diagnosed with estrogen-receptor-positive disease and only women diagnosed with estrogen-receptor-negative disease, there was no difference in recurrence risk.
The researchers also compared the recurrence risk of women who ended their pregnancies (30% of the women) to women who went full-term and delivered babies. There was no difference in recurrence risk between these two groups of women. So there is no reason to tell women who’ve been diagnosed with breast cancer that ending a pregnancy after diagnosis will reduce their recurrence risk.
Interestingly, the researchers found that women who got pregnant after a breast cancer diagnosis had better overall survival than women who didn’t get pregnant after being diagnosed. This benefit also was independent of the cancer’s hormone-receptor status. Overall survival is how long a woman lives, with or without the cancer coming back.
It’s not clear why the women who got pregnant had better overall survival. It could be that the better overall survival was due to better overall health and not because of being pregnant. So we can’t conclude from this study that pregnancy after breast cancer improves survival. But the good news is that pregnancy doesn’t negatively affect recurrence risk or future survival in women who’ve been diagnosed.
This study was a retrospective study, which means the researchers analyzed information that had been collected before the study was designed. Retrospective studies aren’t considered as good as studies that are designed first and then collect new information specifically for that study.
If you’re currently being treated for breast cancer or have been treated in the past and think you might want to become pregnant in the future, this study is reassuring. It suggests that you can get pregnant without affecting your risk of recurrence or survival, no matter the hormone-receptor status of the cancer. You can learn more about fertility issues and planning for children after breast cancer treatment in the Fertility and Pregnancy Issues During and After Breast Cancer pages in the Breastcancer.org Day-to-Day Matters section.