INTRODUCTION TO CANCER
Depending on the type of tumor or sub-types cancer treatment may be strictly limited, besides malignancies as well as dismal prognoses like pancreatic cancer (Figure 1) , there is always a requirement for improved and novel anti-cancer medicines . To meet the need for both cost-effectivenesses together time to repurpose the current medications . Histamine H1 receptor targeted by anti-histamine has minimal side effects and is safe as well as tolerated by many individuals creating a brilliant choice for repurposing. For this possible effect, several mechanisms have been suggested as most people thought to be either wholly or partly H1 receptor-independent, including the Lysosomal cell death or immunological pathways . Fenoxifenadine, loratadine, and desloratadine are a few anti-histamines that revealed anti-inflammatory effects , inhibiting the basal signaling of the H1 receptor . To prevent the release of histamine, mast cell membranes are stabilized by desloratadine. The immunoregulatory activity of myeloid-derived suppressor cells along with the Th2-skewing immune response is promoted by histamine . In colorectal cancer, the th1-response has been revealed to be significant for survival. For the survival of breast cancer and malignant melanoma, loratadine and desloratadine are linked with the improvement previously discovered . In some meta-analyses of data, it was studied whether the related association is seen in several types of the tumor with immune checkpoint inhibitors like anti-PD1 or CTLA-4, to shed more light on potential anti-tumor results of this kind of anti-histamine and whether it can be immunological nature .