Aug. 11, 2003 --There's some reassuring news for breast cancer survivors who want to have a baby. New research shows just because you had breast cancer doesn't mean that getting pregnant will threaten your life.
Researchers complied information about 438 women from three cancer registries. All the women were under 45, had primary invasive breast cancer, and had children after being diagnosed. The study followup period was from four to 10 years after the deliveries.
They also included nearly 3,000 women in a comparison group who also had breast cancer but did not have any children after being diagnosed.
Lower Death Risk for Some
Results, published in the September issue of Cancer, showed that women who gave birth at least 10 months or more after being diagnosed with breast cancer had a 46% lower risk of dying compared with the women who didn't get pregnant after diagnosis.
Women who were pregnant at the time they were diagnosed had similar death rates to those who did not have children following diagnosis.
Researchers say, however, the results "should not be taken as indicative of a true pregnancy- or birth-associated protective affect on survival," due to the possibility of a "healthy mother" bias. In other words, the women who gave birth at least 10 months after a breast-cancer diagnosis might have been healthier -- leading to better survival outcomes.
Researchers saw another difference between women who had babies later versus earlier. Distant metastases -- the spread of cancer from the original site -- were present in less than 1% of women who gave birth at least 10 months after diagnosis, compared with 12% of women who delivered less than 10 months after being diagnosed.
Giving Birth Too Soon Increases Risk
The study also showed that some particular groups had a higher risk of dying. Women who were pregnant when they were diagnosed or who delivered within three months of their diagnosis of breast cancer had higher death rates. Women who were 35 or older at the time of diagnosis and gave birth within a 10-month period after the diagnosis also had increased death rates.
Researchers note that in the past, there have been concerns that hormonal effects of pregnancy may increase the risk of death in women with breast cancer.
Generally, breast cancer is not harmful to the fetus, according to the National Cancer Institute. Their guidelines indicate that women wait two years after treatment before trying to have a baby, so that any early return of cancer could be detected.
The NCI says that pregnant women with breast cancer may be less likely to survive mainly because the diagnosis of their cancer is often delayed and the cancers are more advanced when they are found. Cancers found at later stages are more difficult to treat successfully.