Cytidine deaminase residual activity in serum is a predictive marker of early severe toxicities in adults after gemcitabine-based chemotherapies.

PURPOSE Anticipating toxicities with gemcitabine is an ongoing story, and deregulation in cytidine deaminase (CDA) could be associated with increased risk of developing early severe toxicities on drug exposure. PATIENTS AND METHODS A simple test to evaluate CDA phenotypic status was first validated in an animal model investigating relationships between CDA activity and gemcitabine-related toxicities. Next, relevance of this test as a marker for toxicities was retrospectively tested in a first subset of 64 adult patients treated with gemcitabine alone, then it was tested in a larger group of 130 patients who received gemcitabine either alone or combined with other drugs and in 20 children.

Toxic death case in a patient undergoing gemcitabine-based chemotherapy in relation with cytidine deaminase downregulation.

Gemcitabine is an antimetabolite drug used in the treatment of various solid tumours, including lung, pancreatic or gynaecological cancers. Innovative combinational strategies (e.g.