Desloratadine and loratadine stand out among common H 1 -antihistamines for association with improved breast cancer survival

As tumors maintain an inflammatory microenvironment, anti-inflammatory medication can be useful in cancer therapy. We have previously shown an association with improved survival in melanoma for use of the H -antihistamines desloratadine and loratadine, and here we examine use of H -antihistamines and breast cancer mortality. We investigated use of the six major H -antihistamines (cetirizine, clemastine, desloratadine, ebastine, fexofenadine and loratadine) and breast cancer-specific and overall mortality in a nation-wide register-based study of all 61,627 Swedish women diagnosed with breast cancer 2006-2013. Both peri- and post-diagnostic antihistamine use was analyzed using Cox regression models. Analyses were stratified for age and subgroup analyses based on estrogen receptor status and menopausal status were performed. We found a consistently improved survival of desloratadine users (HR = 0.67; 95% CI 0.55-0.81,