Sentinel lymph node biopsy for breast cancer during pregnancy: A comprehensive update

Background: Pregnant patients diagnosed with breast cancer (PrBC) may receive substantially different treatments compared to general population, considering that certain treatment options cannot be applied during pregnancy due to their potential harmful effects to the foetus. Regarding the use of sentinel lymph node biopsy (SLNB) in pregnant patients, potential concerns include foetal harm from radiation exposure, possible teratogenic effects of blue dyes and maternal anaphylaxis to isosulfan. Objective: The main objective of the present systematic review is to summarize and present current knowledge and up-to-date evidence about the safety and efficacy of SLNB in PABC. Methods: MEDLINE, Google Scholar and UpToDate databases were searched up to 22 January 2023. Articles studying the safety and effectiveness of SLNB in patients for PrBC were eligible for inclusion in the present review. Results: In total, 63 articles that met the inclusion criteria were included in this study. Forty-seven articles were strongly in favour of performing SLNB in PABC, 4 articles were partially in favour, 10 articles were strongly against and 2 articles were partially against performing SLNB in PABC. Sub-categorization based on type of study showed that the majority of studies in favour were of higher level of evidence than those against. Furthermore, there were overall 12 studies reporting on outcomes. There were overall 382 women with PrBC that underwent SLNB. Full data were reported for 237 cases. Overall live birth rate was 95.8%, while overall neonatal complication rate was 3.4%. No case of maternal side effects or anaphylactic reaction, maternal death, stillbirth and neonatal death was reported (0%). Conclusions: Sentinel lymph node biopsy seems to be safe and effective technique for breast cancer during pregnancy.