Surgical Management of Breast Cancer Diagnosed During Pregnancy: A Narrative Review

Abstract

Background: Breast cancer diagnosed during pregnancy (PrBC) represents a rare but increasingly prevalent clinical scenario, driven by delayed childbearing and increasing breast cancer incidence among premenopausal women. PrBC is characterized by distinct biological features – including a predominance of hormone receptor-negative, poorly differentiated, and lymph node-positive tumors – and poses unique therapeutic constraints. Surgery constitutes the cornerstone of locoregional management; however, evidence-based guidance remains limited to observational data and expert consensus, because randomized controlled trials are ethically precluded in this population. Methods: A narrative review of the current literature was conducted, incorporating prospective cohort studies, systematic reviews, meta-analyses, and major international guidelines – including the 2023 ESMO Expert Consensus Statements, the 2025 ASCO Sentinel Lymph Node Biopsy Guideline Update, the 2025 RCOG Green-top Guideline No. 12 on Pregnancy and Breast Cancer, and the NCCN Clinical Practice Guidelines in Oncology for Breast Cancer (Version 2.2026) – to synthesize evidence on all aspects of surgical care for breast cancer diagnosed during gestation. Results: Surgery can be performed safely at any stage of pregnancy. The optimal procedure – breast-conserving surgery (BCS) or mastectomy – is determined by tumor biology, gestational age, and the feasibility of adjuvant radiotherapy, which must be deferred until the postpartum period. Sentinel lymph node biopsy (SLNB) using technetium-99m is considered safe and endorsed by most current guidelines as the standard axillary staging approach in clinically node-negative PrBC, while blue dye agents such as isosulfan blue and methylene blue are discouraged. Venous thromboembolism (VTE) prophylaxis with low-molecular-weight heparin represents a critical yet historically underemphasized component of perioperative care, given the compounded thrombotic risk conferred by pregnancy, malignancy, and surgery. Conclusion: Definitive surgical treatment of PrBC, delivered within a dedicated multidisciplinary framework, can achieve locoregional control comparable to that in non-pregnant patients. Therapeutic conservatism at the expense of oncological adequacy must be avoided. Prospective registry data and validation of novel axillary staging approaches – including targeted axillary dissection – in the PrBC setting remain important research priorities.