Pregnancy Has No Impact on Breast Cancer Survival, Does Delay Treatment, Diagnosis

Young women who develop breast cancer during their pregnancy, or who are diagnosed within one year of their pregnancy, have no difference in rates of local recurrence, distant metastases and overall survival compared to other young women with the disease, according to researchers at The University of Texas M. D. Anderson Cancer Center.

However, the largest single-institution study to look at pregnant breast cancer patients finds that women with Pregnancy Associated Breast Cancer (PABC), are more likely to be diagnosed later with advanced stages of the disease and, thus, have necessary treatment delayed.

The findings are published in the March 15 issue of the journal Cancer.

"Breast cancer in young women is a highly aggressive disease, and it's important that we study it in hopes of making a difference in terms of treatment," said Beth Beadle, M.D., a radiation oncology resident at M. D. Anderson and the study's first author. "When we looked at our young breast cancer population, a relatively large percentage had disease affiliated with pregnancy. We thought it would be really instructive to review our data to determine how we can best serve these women."

It's estimated that up to 3.8 percent of pregnancies are complicated by breast cancer, and approximately 10 percent of breast cancer patients under age 40 develop the disease during pregnancy, said the researchers. As the age for first and subsequent pregnancies increases and intersects with advances in imaging and screening, this statistic will only continue to climb, explained George Perkins, M.D., associate professor in M. D. Anderson's Department of Radiation Oncology.

"Because we see care for large volume of patients who are young, as well as those who are young and pregnant, we wanted to see if there was something additive going on that is attributed to pregnancy, or if the response to treatment and behavior of the disease is a phenomenon of young age itself," said Perkins, the study's senior author.

For the retrospective study, Beadle, Perkins and their colleagues reviewed the records of 652 M. D. Anderson breast cancer patients, all were 35-years-old or younger at the time of diagnosis and treated at M. D. Anderson between 1973 and 2006. Of those women, 104 (15.6 percent) had PABC - 51 developed their cancer during their pregnancy and 53 developed the disease within one year post-pregnancy. Median follow-up for PABC patients compared to non-PABC patients was 95.5 months versus 91 months respectively.

When comparing the PABC and the non-PABC cohorts, the researchers found no statistical difference between the 10-year rates of: locoregional recurrence (23.4 percent, PABC; 19.2 percent, non-PABC), metastasis (45.1, percent PABC; 38.9 percent, non-PABC), or overall survival (64.6 percent, PABC; 64.8 percent, non-PABC).

"What we did find, however, is that women with PABC presented with more advanced disease, both in the breast and lymph nodes," said Beadle. "These women seem to have a significant delay in diagnosis, and their symptoms were not identified as breast cancer for an extended period of time - putting them at a disadvantage by withholding necessary treatment."