A study of young women found that pregnancy after a diagnosis of estrogen receptor-positive breast cancer does not appear to increase the risk of cancer recurrence. These results were presented at the eighth European Breast Cancer Conference.
Breast cancer is the most common type of cancer among women of childbearing age. For women who develop breast cancer before completing their families, many questions arise about fertility preservation and the safety of a subsequent pregnancy. In the case of estrogen receptor-positive breast cancer, there has been some uncertainty about whether the hormonal changes of pregnancy could increase the risk of cancer recurrence.
To explore whether pregnancy affects risk of breast cancer recurrence, researchers from several countries conducted a study among 333 women who had become pregnant after a diagnosis of breast cancer, and 874 similar women who did not become pregnant.
The women aged in range from 21 to 48 (average age was 34).
- Recurrence risk was similar in the women who did and did not become pregnant. This was true for women with estrogen receptor-positive breast cancer and for women with estrogen receptor-negative breast cancer.
- In the subset of women who became pregnant soon after their breast cancer diagnosis (within two years), risk of recurrence was actually somewhat lower than in the women who did not become pregnant. The researchers recommend caution in interpreting this result, noting “pregnancy within two years of diagnosis should be regarded as safe, and not as protective.”
- Miscarriage, abortion, and breastfeeding did not appear to affect breast cancer outcome.
Although this study does not provide definitive proof of the safety of pregnancy after breast cancer, these results should be reassuring to women who wish to become pregnant after a breast cancer diagnosis.
Because some types of cancer treatment can affect a woman’s fertility, women who are interested in becoming pregnant should discuss the issue of fertility preservation with their physician before cancer treatment begins.
Reference: Azim Jr H, Kroman N, Ameye L et al. Pregnancy following estrogen receptor-positive breast cancer is safe – results from a large multi-center case-control study. Paper presented at: eighth European Breast Cancer Conference (EBCC8); March 21-24, 2012; Vienna, Austria. Abstract 21.
Posted March 30, 2012