According to the results of a study conducted at the M. D. Anderson Cancer Center, women who are diagnosed with breast cancer and treated with chemotherapy while pregnant have a better disease-free survival (survival without a cancer recurrence or a new cancer) than women who are not pregnant at the time of diagnosis. Overall survival was similar in the two groups of patients. These results were presented at the 2010 Breast Cancer Symposium.
Previous reports have suggested that being pregnant at the time of diagnosis worsens breast cancer outcomes. This may have been due to older approaches to cancer treatment, in which pregnant women received less effective cancer treatment than non-pregnant women or delayed cancer treatment until after the birth of the baby.
A recent study compared breast cancer outcomes between pregnant and non-pregnant women who were treated with 5-fluorouracil, doxorubicin, and cyclophosphamide (FAC). In pregnant women, treatment with FAC was administered after the first trimester of pregnancy. When additional therapies—such as hormonal therapy—were warranted, these were started after the woman gave birth. Each of the 54 pregnant breast cancer patients treated was matched with two non-pregnant patients based on age and stage of cancer.
Overall survival between pregnant and non-pregnant women was similar. In fact, pregnant women appeared to have a slightly better overall five-year survival (77%) than their non-pregnant counterparts (72%). This difference, however, was not statistically significant and may be the result of chance alone.
For five-year disease-free survival, results were significantly better for pregnant women: 74% versus 56% for non-pregnant women.
These results suggest that with current approaches to treatment, pregnancy does not worsen breast cancer outcomes. In a prepared statement, one of the authors of the study stated “Now, when we are counseling breast cancer patients who are pregnant, we can say that they should have every expectation that they will do as well as our non-pregnant patients, and that they should start their treatment in the second or third trimester without delay.”
 Litton JK, Warneke CL, Hahn K, et al. Case-control analysis of patients (pts) treated with chemotherapy during pregnancy for breast cancer (BC). Presented at the Breast Cancer Symposium, Washington, DC, October 1-3, 2010. Abstract 105.
 MD Anderson News Release. UT MD Anderson Study Finds Women Treated for Breast Cancer While Pregnant Have Improved Survival. 09/29/10.