Incidence, risk factors, and obstetrical outcomes of women with breast cancer in pregnancy.

Breast cancer in pregnancy is a rare condition. The objective of our study was to describe the incidence, risk factors, and obstetrical outcomes of breast cancer in pregnancy. We conducted a population-based cohort study on 8.8 million births using data from the Healthcare Cost and Utilization Project - Nationwide Inpatient Sample from 1999-2008. The incidence of breast cancer was calculated and logistic regression analysis was used to evaluate the independent effects of demographic determinants on the diagnosis of breast cancer and to estimate the adjusted effect of breast cancer on obstetrical outcomes. There were 8,826,137 births in our cohort of which 573 cases of breast cancer were identified for an overall 10-year incidence of 6.5 cases per 100,000 births with the incidence slightly increasing over the 10-year period. Breast cancer appeared to be more common among women >35 years of age, odds ratio (OR)=3.36 (2.84-3.97); women with private insurance plans, OR=1.39 (1.10-1.76); and women who delivered in an urban teaching hospital, OR=2.10 (1.44-3.06). After adjusting for baseline characteristics, women with pregnancy-associated breast cancer were more likely to have an induction of labor, OR=2.25 (1.88, 2.70), but similar rates of gestational diabetes, preeclampsia, instrumental deliveries, and placental abruption. The incidence of breast cancer in pregnancy appears higher than previously reported with women over 35 being at greatest risk. Aside from an increased risk for induction of labor, women with breast cancer in pregnancy have similar obstetrical outcomes.

Pregnancy-associated breast cancer: a review for the obstetrical care provider.

Breast cancer is uncommon in pregnancy, but obstetrical care providers should nevertheless be familiar with the presenting signs and symptoms. The incidence of breast cancer in pregnancy and the postpartum period ranges from 2.3 to 40 cases per 100 000 women. Over 90% of patients with breast cancer in pregnancy or during lactation present with a palpable mass, and most often (84%) these are self-reported by patients. Less frequently, breast cancer will present as breast erythema, breast swelling, bloody nipple discharge, or local or distant metastasis. The histology of tumours appears to be similar in women who are pregnant or recently delivered and in age-matched women who are not pregnant. However, the stage of disease at diagnosis is more advanced in women who are pregnant or recently delivered and consequently incurs a worst prognosis, likely due to a delay in diagnosis. Although the majority of palpable breast masses are benign, breast examinations should routinely be performed in pregnant women, and identified masses should be promptly evaluated.