Medical Policy Subject: Tumor Chemoresistance and Chemosensitivity Assays

Tumor chemoresistance and chemosensitivity assays have been investigated as a means of predicting tumor response to various chemotherapies. Tumor chemoresistance assays are focused on identifying resistant drugs. Tumor chemosensitivity assays are intended to predict the sensitivity of various tumors to chemotherapeutic agents. These assays have been proposed for use by oncologists to select chemotherapy regimens for individual patients. A variety of assays have been developed that differ in their processing and in the technique used to measure sensitivity or resistance. However, all involve the same four basic steps: 1) isolation of cells, 2) incubation of cells with drugs, 3) assessment of cell survival, and 4) interpretation of the result. A variety of techniques have been evaluated to assess cell survival, including the DISC (differential staining cytotoxicity) assay, the thymidine incorporation assay, fluorescence (cytoprint) assays, and the MTT (methylthiazolyl-diphenly-tetrazolium bromide) assay.