Expression of the high-affinity fluoropyrimidine-preferring nucleoside transporter hCNT1 correlates with decreased disease-free survival in breast cancer.

Purpose: Nucleoside and nucleobase derivatives are currently used in the treatment of a variety of solid tumors; however, the role of plasma membrane transporters as biomarkers of drug metabolism has not been fully addressed. Thus, the purpose of this study was to determine whether the concentrative nucleoside transporter hCNT1 is a predictive marker of therapeutic response.

Methods: We studied a cohort of 90 breast cancer patients who were treated with cyclophosphamide-methotrexate-5-fluorouracil after surgery and then monitored for up to 108 months.