MOLECULAR MARKERS FOR CAPECITABINE THERAPY: A REVIEW

Capecitabine an oral prodrug of 5- fluorouracil is widely used for the treatment of variety of solid tumors, particularly colorectal cancer. However it is not devoid of toxicities and may limit therapy. A little is known about predictors of toxicity, response and survival in patients treated with capecitabine. The pharmacogenetic testing methods can identify such variants and thus indicate those patients who are at risk for adverse effects with capecitabine. Various studies have been carried out to assess the various genetic predictive and prognostic markers with treatment. The purpose of this review is to describe the comprehensive reports and draw conclusion with the available information on capecitabine pharmacogenetics and future directions on ongoing research.  An extensive literature search was carried out on the genes encoding the enzymes involved in the metabolism of capecitabine. Overall, evidence indicates multiple genes associated with the response/toxicity with capecitabine therapy, however majority of reports indicate DPD deficiency as a source of life-threatening toxic effects. Hence, prospective studies correlating the enzymes and the concentration of the drug and its metabolites in the body are needed before validated SNP tests can enter routine clinical practice.