Taxanes for the treatment of breast cancer during pregnancy: an international cohort study

Biology, care, and outcomes of gestational breast cancers: a review

PURPOSE

The incidence of gestational breast cancers, breast cancers diagnosed during pregnancy, is increasing. There is a critical need to understand the pathophysiology, treatment recommendations, and remaining questions regarding care and therapeutics for this complex condition.

METHODS

Here, we review existing data regarding evaluation and management of gestational breast cancer, including safe imaging modalities, timing and choice of chemotherapy, evidence regarding targeted therapies during pregnancy. We highlight the importance of multidisciplinary care including oncologic, obstetric, and psychosocial care.

RESULTS

Gestational breast cancers are associated with unique biologic and clinicopathologic features that are impacted by physiologic changes of pregnancy such as upregulation of target genes associated with cell proliferation and immune regulation. Patients with gestational breast cancers more often present at advanced stages, are more likely to have aggressive tumor subtypes (i.e., triple negative or HER2 positive), and overall have worse prognoses than patients with non-gestational breast cancers. In this review, we synthesize recommendations for treatment strategies based on pregnancy trimester, optimal timing and choice of surgery, chemotherapy, targeted therapies, and psychosocial support.

CONCLUSION

Developing a framework for clinical care and treatment of patients with gestational breast cancers is integral to improving outcomes for patients with gestational breast cancers. Optimal treatment includes collaborative management with a multidisciplinary team dedicated to both maternal and fetal care.

Managing pregnancy-associated breast cancer: A practical approach

Pregnancy-Associated Breast Cancer (PABC) is a rare but complex condition that presents both professional and ethical challenges. Diagnosis is often delayed due to breast changes associated with pregnancy and puerperium, which can mask malignant findings. Management requires a multidisciplinary approach that carefully balances maternal and fetal risks. Chemotherapy is generally reserved for the second and third trimesters to avoid teratogenicity, with anthracyclines being the most well-studied and safest agents in this setting. Surgical decisions are influenced by factors such as cancer stage, gestational age, and the timing of potential radiation therapy. Notably, radiation therapy, endocrine therapy, and most targeted therapies are contraindicated during pregnancy due to potential harm to the fetus. Comprehensive care should include robust social and mental health support for the mother and her family to help navigate the physical and emotional challenges during this period.

Multidisciplinary Management of Pregnancy-Associated Breast Cancer

Breast cancer during pregnancy is uncommon; however, it is one of the most common malignancies affecting pregnant women. Pregnancy-associated breast cancer (PABC) is a complex entity characterized by unique risk factors, presentation, and pathology. Furthermore, although management generally aims to mirror that for nonpregnant patients, there are distinct aspects of oncologic care delivery specific to PABC. The focus is on optimizing maternal outcomes while maximizing maternal and fetal safety. A multidisciplinary approach is key, and the timing of various treatment modalities is critical. Postdelivery care and counseling are also imperative to address issues such as contraception, breastfeeding, and future fertility. In the present review, we discuss the current knowledge base and the diagnostic and treatment landscape for PABC, including recent literature and practice pattern updates.

Outcomes of patients treated with chemotherapy for breast cancer during pregnancy compared with nonpregnant breast cancer patients treated with systemic therapy

INTRODUCTION

Prior studies of patients treated for breast cancer during pregnancy (PrBC) report mixed outcomes and are limited by substandard treatment, small cohorts, and short follow-up. This study compared survival outcomes of PrBC patients treated with chemotherapy during pregnancy with nonpregnant patients matched by age, year of diagnosis, stage, and subtype.

METHODS

PrBC patients treated from 1989 to 2022 on prospective institutional protocols were eligible. Disease-free survival (DFS), overall survival (OS), and progression-free survival (PFS) were estimated using the Kaplan-Meier method and multivariable Cox proportional hazards regression.

RESULTS

Among 143 PrBC and 285 nonpregnant patients, median follow-up was 11.4 years. Survival differences were statistically significant, with median DFS and OS not attained for PrBC patients versus 5.6 years (95% confidence interval [CI], 3.6-15.4; p = .0001) and 19.3 years (95% CI, 14.1-not estimated; p = .0262) for nonpregnant patients, respectively. Median PFS was 24.1 years (95% CI, 15.8-not estimated) for PrBC patients versus 8.4 years (95% CI, 6.4-10.9) for the nonpregnant cohort (p = .0008). Study cohort was associated with DFS, PFS, and OS in multivariable analyses, with the nonpregnant cohort having increased risks of disease recurrence (hazard ratio [HR], 1.91; 95% CI, 1.33-2.76; p = .0005) and disease progression or death (HR, 1.68; 95% CI, 1.19-2.39; p = .0035), and shorter OS (HR, 1.52; 95% CI, 1.01-2.29; p = .0442).

CONCLUSION

These data suggest that PrBC patients treated with chemotherapy during pregnancy have at least comparable, if not superior, outcomes than nonpregnant patients with similar age, cancer stage, and subtype. Analyses excluding patients with postpartum breast cancer were unable to be performed and are a priority for future confirmatory studies.

Child outcomes after prenatal exposure to platinum and taxane-based chemotherapy: an unplanned interim analysis of the international network on cancer, infertility, and pregnancy study

Background

Platina and taxanes are frequently used chemotherapeutic agents to treat cancer, also when diagnosed during pregnancy. This report presents an interim analysis of the largest series of children prenatally exposed to platinum and/or taxane agents and aims to determine their physical health and neurocognitive outcomes.

Methods

As part of a multicentre, prospective cohort study (ClinicalTrials.gov: NCT00330447), children born between 2000 and 2022 were assessed between 2005 and 2024 at ages 1.5-18 years (interim analysis; median length of follow-up, 3.2 years (IQR 3.0-6.4)) by a comprehensive neurocognitive test battery, parent-reported questionnaires, and a physical assessment. Mixed-effects regression and Type III Analysis of Variance models were used to investigate associations between these outcomes and platinum/taxane cumulative dose and agent type, with best-fit models corrected for age and covariates (gestational age at birth, chemotherapy timing, other chemotherapy, sex, parental education level, maternal death).

Findings

In total, 144 children were included (13% exposed to platinum, 62% to taxanes, 25% to both). Of these, 101 were assessed at age 1.5 years, 96 at age 3, 63 at age 6, 32 at age 9, 18 at age 12, 7 at age 15, and 2 at age 18 years. Neurocognitive outcomes were within normal ranges across all ages, compared with test-specific normative data. Eight children (6%) reported ototoxicity, seven (5%) reported chronic medical conditions, three (2%) had congenital malformations, and two (1%) were diagnosed with Attention-Deficit Hyperactivity Disorder. Thirty-three children (23%) needed extra neurocognitive support, of which 64% were born preterm. Children prenatally exposed to paclitaxel scored lower on visuospatial (β = 0.64 ± 0.21, p = 0.0052) and verbal memory (β = 0.68 ± 0.27, p = 0.015) than those exposed to docetaxel.

Interpretation

In this interim analysis, we found normal neurocognitive outcomes and no increase in congenital malformations nor medical conditions after prenatal exposure to platinum/taxane-based chemotherapy. However, owed to the limited number of older children, further investigation regarding their potential neurotoxicity and its long term effects is necessary in follow-up studies with larger samples.

Funding

Kom Op Tegen Kanker, KWF Kankerbestrijding, Stichting Tegen Kanker, Cooperatio program, Research Foundation Flanders.

Choosing the appropriate pharmacotherapy for breast cancer during pregnancy: what needs to be considered?

INTRODUCTION

Breast cancer is the most commonly diagnosed malignancy during pregnancy. Breast cancer during pregnancy is a challenging clinical condition requiring proper and timely multidisciplinary management.

AREAS COVERED

This review focuses on the management of breast cancer during pregnancy with a focus about the current state-of-the-art on the feasibility and safety of pharmacotherapy approaches in this setting.

EXPERT OPINION

Multidisciplinary care is key for a proper diagnostic-therapeutic management of breast cancer during pregnancy. Engaging patients and their caregivers in the decision-making process is essential and psychological support should be provided. The treatment of patients with breast cancer during pregnancy should follow the same recommendations as those for breast cancer in young women outside pregnancy but taking into account the gestational age at the time of treatment.Anthracycline-, cyclophosphamide-, and taxane-based regimens can be safely administered during the second and third trimesters with standard protocols, preferring weekly regimens whenever possible. Endocrine therapy, immune checkpoint inhibitors, and targeted agents are contraindicated throughout pregnancy, also due to the very limited data available to guide their administration in this setting. During treatment, careful fetal growth monitoring is mandatory, and even after delivery proper health monitoring for the children exposed in utero to chemotherapy should be continued.