Are Taxanes Safe for Pregnant Patients with Breast Cancer?

Chemotherapy during pregnancy gives many clinicians pause. Although use of anthracyclines beyond the first trimester is considered safe, information on other cancer drugs, including taxanes, is more limited.

In a retrospective, international cohort study, researchers assessed maternal and neonatal adverse events associated with use of taxanes during pregnancy in patients with breast cancer. Of 103 patients, (41% from the U.S.), 77% had stage II or III disease. Paclitaxel was the most commonly administered taxane (96%), mostly at a dose of 80 mg/m² weekly. The median gestational age at initiation of any chemotherapy was 16 weeks and for taxane therapy was 28 weeks.

The prevalence of maternal adverse events was low (grade 3–4, 6.8%) and similar to that expected in a nonpregnant breast cancer population. Despite the need to administer steroids with paclitaxel, the prevalence of gestational diabetes (5.3%) and hypertensive disorders of pregnancy (4.3%) was not increased relative to the general population.

The live birth rate was 98% with a median gestational age of 37 weeks. Overall, 43% of infants were born preterm (<37 weeks), which is higher than in the general population but comparable to the rate reported with use of anthracycline-based chemotherapy in pregnancy. Prematurity rates decreased over time, from 67% in 2005–2009 to 23% after 2020. Importantly, the rate of congenital malformations was similar to that in the general population (~2%). Among 28 infants followed for a median of 42 months, 24 were reported as healthy.