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

ABSTRACT

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.

KEYWORDS:

• Pregnancy during breast cancer
• pregnancy
• breast cancer
• chemotherapy
• endocrine therapy
• targeted therapy
• immunotherapy

Article highlights

• PrBC is a critical clinical situation that requires a multidisciplinary management including both oncology and non-oncology medical specialists.

• The use of chemotherapy remains the mainstay in managing breast cancer during pregnancy and should be administered according to current standard protocols but only in the second and third trimesters of gestation; use of endocrine therapy, targeted agents and immunotherapy is contraindicated during pregnancy.

• Anthracycline-, cyclophosphamide-, and taxane-based regimens are safe in the second and third trimesters of gestation and should be considered as the first choice when clinically indicated.

• Fetal growth monitoring during pregnancy is mandatory, and after delivery health monitoring is recommended to exclude the occurrence of long-term complications.

Declaration of interest

M Lambertini reports being in an advisory role for Roche, Lilly, Novartis, AstraZeneca, Pfizer, Seagen, Gilead, MSD and Exact Sciences and receiving speaker honoraria from Roche, Lilly, Novartis, Pfizer, Sandoz, Libbs, Daiichi Sankyo, Knight and Takeda, Travel Grants from Gilead and Daiichi Sankyo, and research support (to the Institution) from Gilead outside the submitted work.

All other authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Acknowledgments

M Lambertini acknowledges the Italian Association for Cancer Research (“Associazione Italiana per la Ricerca sul Cancro”, AIRC; MFAG 2020 ID 24698) for supporting his research in the field of breast cancer in young women and oncofertility.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.