Study of ABCB1,SLC22A16 Drug Transporter Genes and Doxorubicin and Cyclophosphamide Toxicity in Brest Cancer Patient

breast cancer is the most common cancer diagnosed in women .Breast cancer can occur in both men and women, but it's far more common in women. The etiology of breast cancer possesses a multifactorial origin , showing as risk factors reproductive age, early menarche, late menopause, nulli parity, exogenous hormones ,smoking, obesity, diet, alcohol consumption, physical inactivity, and genetic and environmental factors(1). Chemotherapy combination usually used in treat breast cancer specially cyclophosphamide which is alkylating agent and doxorubicin which is cytotoxic drug. Doxorubicin entry to the cell is facilitated by the solute importer SLC22A16,the efflux of AC drugs uses several ATP-binding cassette transporters (ABC),( ABCB1, ABCC1, ABCC2, ABCG2)(2),(7). Most chemotherapeutic agents are not specific against neoplastic cells , also affecting normal cells. Which result in a wide range of adverse reactions in virtually all tissue of body. Unfortunately, chemotherapy-induced toxicities are commonly affecting cancer patients with various intensity, and could be the reason for treatment delays and significantly lowered quality of life. Hematological and gastrointestinal toxicities are common in patients treated with cyclophosphamide and doxorubicin(3). Extremely high proliferative capacity of hematopoietic system makes it the collateral target for chemotherapeutic agents. Chemotherapy-induced neutropenia are , because of the high susceptibility of neutrophil lineage to cytotoxic effects of cancer treatment. The drug-induced destruction of neutrophil precursors in bone marrow is the main cause of those symptoms. Decrease in neutrophil count is managed by the dose reduction and delays that decrease the dose intensity, where is maintaining the dose is important for favorable response to treatment(3). Another frequent and serious myelotoxic symptom in breast cancer chemotherapy is anemia. This condition may emerge from the disease itself, but the effect of concomitant administration of cytotoxic drugs is also the cause of drop in the hemoglobin level. Anemia has deleterious effect on patients' quality of life as well as on the treatment response. The suspected causes include blood loss, reduced or impaired erythrocytes production and high rate of red blood cells destruction or their reduced survival(4). Chemotherapy-induced nausea and vomiting (CINV) is a common severe side effect for cancer patients undergoing emetic chemotherapy. The complete pathophysiology of CINV is not known but gastrointestinal (GI) side effects associated with anticancer chemotherapy are traditionally thought to be attributable to mucosal damage. Nausea is complex in nature and probably depending on more than one etiological factor . Different pathways have been identified for acute and delayed CINV Also, nausea and vomiting can result in anorexia, decreased performance status, metabolic imbalance, wound dehiscence, esophageal tears and nutritional deficiency(5). In the study we will focuse on the analysis of the relations between the polymorphic variants in some drug transporter genes with known or potential role in the AC-induced toxicity. Single nucleotide polymorphisms will analyzed in genes encoding proteins Involved in AC drug transport