A New Prognostic Score Based on Cell-Mediated Immunity for Cytomegalovirus Infection After Transplantation

Abstract

Breastfeeding; Breast cancer

Lactancia materna; Cáncer de mama

Lactància materna; Càncer de mama

Background: We investigated safety of breastfeeding after breast cancer in patients carrying germline BRCA pathogenic or likely pathogenic variants. Methods: This was an international, multicentre, hospital-based, retrospective cohort study including BRCA carriers diagnosed with stage I-III invasive breast cancer at age 40 years or younger between January 2000 and December 2020 (NCT03673306). Locoregional recurrences and/or contralateral breast cancers, disease-free survival (DFS) and overall survival (OS) were compared between patients who breastfed after delivery and those who did not. Results: Among 4732 patients included from 78 centres worldwide, 659 had a pregnancy after breast cancer diagnosis, of whom 474 delivered a child. After excluding patients with uptake of bilateral risk-reducing mastectomy prior to delivery (n = 225) or unknown breastfeeding status (n = 71), 110 (61.8%) breastfed (median duration 5 months) and 68 (38.2%) did not breastfeed. Compared to patients in the no breastfeeding group, those who breastfed were more frequently nulliparous at breast cancer diagnosis (61.8% vs 45.6%) and did not report prior smoking habit (71.8% vs 57.4%).After a median follow up of 7.0 years following delivery, 7-year cumulative incidence of locoregional recurrences and/or contralateral breast cancers was 29% in the breastfeeding group and 37% in the no breastfeeding group (adjusted subdistribution hazard ratio[HR]=1.08, 95%CI 0.57-2.06). No difference in DFS (aHR = 0.83, 95%CI 0.49-1.41) nor in OS (aHR = 1.32, 95%CI 0.31-5.66) was observed. Conclusions: Breastfeeding did not appear to be associated with a higher risk of developing locoregional recurrences or contralateral breast cancers, emphasizing the possibility of achieving a balance between maternal and infant needs without compromising oncological safety.

LD received a research fellowship grant from the “Instituto de Salud Carlos III” [FI22/00252]. OB’s research activity is partly supported by Instituto de Salud Carlos III (ISCII) (grant numbers PI19/01710 and PI22/01019) (Cofunded by European Regional Development Fund, ERDF-ESF, a way to build Europe) and RICORS (redes de Investigación Cooperativa Orientadas a Resultados en Salud) consortia by the Instituto de Salud Carlos III. In addition, the work was partially funded by a European Union’s Horizon 2020 research and innovation program under grant agreement No 754995 (EUTRAIN). The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the funding institutions.