Purpose: Breast cancer is the most common malignancy occurring during pregnancy. Because more women delay childbearing, the diagnosis of cancer during pregnancy will likely increase. Case reports exist in the literature regarding the treatment of pregnant women with breast cancer, but few are prospective and few provide long-term follow-up on the neonate exposed to chemotherapy. In this report, 130 women diagnosed with breast cancer were reported to our voluntary national registry and followed up prospectively.
Patient and Methods: The Cancer and Pregnancy Registry is a voluntary registry that monitors the clinical course, treatment, and disease outcome of women diagnosed with cancer during pregnancy and the perinatal and neonatal outcomes of their children.
Results: Of the 130 diagnosed, 120 were diagnosed with a primary tumor, 8 with a recurrence, and 2 with a new primary cancer. Mean maternal age at diagnosis was 34.8 ± 4.2 years. Mean gestational age at diagnosis was 13.2 ± 8.1weeks. Gestational age was 12.8 ± 7.8 weeks for patients with primary disease and 16.25 ± 11 weeks for those with recurrent cancer. One hundred thirteen women were followed up for mean of 3.14 ± 2.5 years. Of those followed up, 103 were diagnosed with primary breast cancer during pregnancy, 8 with a recurrence, and 2 with a new primary. Recurrence was reported in 30 patients at an average of 16.2 ± 10.8 months from delivery to recurrence. Twenty-one patients are deceased with an average of 24.71 ± 15.32 months from delivery to death. Only 42% were diagnosed with an estrogen-positive tumor and 35% of cases had a progesterone receptor-positive tumor. Human epidermal growth factor receptor 2 was positive in 25% of patients. Chemotherapy was given during pregnancy in 104 cases; the first treatment was given at a mean gestational age of 20.4 ± 5.4 weeks. The malformation rate of exposed neonates was 3 not greater than the general population. Survival by stage for a primary diagnosis in pregnancy is as follows: stage I, 100%; stage II, 86%; stage III, 86%; and stage IV, 0%.
Discussion: Pregnant women diagnosed with breast cancer can receive treatment comparable with nonpregnant women leading to a similar survival when matched for stage at diagnosis. The majority of children who were exposed to chemotherapy in utero did not demonstrate significant complications. We report the single largest cohort of women diagnosed with breast cancer during pregnancy.