A woman who is pregnant and has breast cancer is more likely to recover and survive disease-free than a woman who is not pregnant and has breast cancer, researchers at the University of Texas MD Anderson Cancer Center reveal. These findings, which were presented by Jennifer Litton M.D. at the 2010 Breast Cancer Symposium, will surprise most experts because people tend to associate pregnancy with worse cancer outcomes. Dr. Litton is assistant professor at MD Anderson’s Department of Breast Medical Oncology.

Dr. Litton said:

Until now, older registry studies showed that breast cancer patients treated while pregnant had a worse outcome. However, in the past, these patients weren’t always treated consistently with standard of care chemotherapy and often delayed their therapy until after delivery.” said Litton, the study’s first and corresponding author. “Given MD Anderson’s experience in treating pregnant patients and our registry, we were able to look at these women treated by the same physicians, at the same institution, with the same standard of care.

The first protocol which examined the chemotherapeutic regimen for the management of breast cancer during pregnancy was opened by Richard Theriault, D.O., in 1992. Theriault published seminal studies which demonstrated the efficacy and safety of the regimen for the pregnant mother and her child – this regimen has since been adopted as standard care. MD Anderson has the oldest, active prospective registry anywhere in the world, which follows the health of women who had breast cancer while pregnant, as well as their children.

Dr. Litton and team selected 75 females who had been treated for breast cancer while they were pregnant (cases). They were compared to 150 non-pregnant women (controls) who were treated for breast cancer by using the centers tumor registry and the Department of Breast Medical Oncology database.

All the women had been treated at MD Anderson between 1989 and 2008 – they were matched based on year of diagnosis, age and cancer stage. Those who gave birth within one year of being diagnosed were not included in the comparison group.

All the patients had received 5-fluorouracil, doxorubicin and cyclophosphamide (FAC), a standard chemotherapy regimen. Therapy for the pregnant women started after their first trimester was over. All the women received clinically-indicated additional therapies – the pregnant patients received those after giving birth. The median follow-up was 4.16 years.

73.94% of those in the pregnant group were alive and disease free after five years, compared to 55.75% of the controls (women who were not pregnant during breast cancer). Overall survival among the pregnant group was 77.42%, compared to 71.86% among the controls (not statistically significant).

Litton said:

From this data set and our study, we are not sure why our pregnant breast cancer patients had better outcomes than those who were not,” said Litton. “Is there something biological in the milieu of pregnancy that changes the response to chemotherapy? Or were these patients treated more aggressively?

The researchers say they do not know why the disease-free overall survival rates were so different in the two groups. They say finding out is a “research priority”.

Senior study author, Richard Theriault, said:

MD Anderson has a long history of being at the forefront of treating pregnant women for breast cancer, and, through our research, we’ve found it safe for both mother and child, and ultimately developed the standard of care. 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.

Source: MD Anderson Cancer Center (University of Texas)

Written by Christian Nordqvist