Pregnancy around the time of, or after, diagnosis of breast cancer is not associated with an increased risk of death, a study published in JAMA Oncology has shown.1
An increasing number of women are becoming pregnant around the time of, or after, a diagnosis of breast cancer; however, there are limited data on the impact of pregnancy on survival in women with breast cancer.
Using retrospective data obtained from 7553 women aged 20 to 45 years at the time of invasive breast cancer diagnosis, researchers compared the overall survival of women with breast cancer diagnosed during pregnancy or in the postpartum period with that of women who had breast cancer but did not experience pregnancy.
Investigators classified women into 4 groups: no pregnancy (reference group), pregnancy before breast cancer, pregnancy-associated breast cancer, and pregnancy following breast cancer. Median age at diagnosis was 40 years.
Results showed that the 5-year actuarial survival rate was 87.5% (95% CI, 86.5-88.4) for women with no pregnancy vs 85.3% (95% CI, 82.8-87.8) for women with pregnancy before breast cancer (age-adjusted hazard ratio [HR], 1.03; 95% CI, 0.85-1.27; P =.73).
The 5-year actuarial survival rate for women with pregnancy-associated breast cancer was 82.1% (95% CI, 78.3-85.9) compared with 87.5% (95% CI, 86.5-88.4) for women who did not become pregnant (age-adjusted HR, 1.18; 95% CI, 0.91-1.53; P =.20), suggesting no significant difference in survival between women with no pregnancy and those with pregnancy before breast cancer or those with pregnancy-associated breast cancer.
However, researchers found that the 5-year actuarial rate for women who had pregnancy 6 months or more after diagnosis was 96.7% (95% CI, 94.1-99.3) vs 87.5% (95% CI, 86.5-88.4) for women who did not experience pregnancy (age-adjusted HR, 0.22; 95% CI, 0.10-0.49; P <.001).
Clinicians may wish to consider explaining that the risk of death is lowest if pregnancy occurs 6 months or more after diagnosis for breast cancer survivors hoping to conceive.
1. Iqbal J, Amir E, Rochon PA, et al. Association of the timing of pregnancy with survival in women with breast cancer. JAMA Oncol. 2017 March 9. doi: 10.1001/jamaoncol.2017.0248 [Epub ahead of print]