Preliminary Study of the Clinical Features of the Chemosensitivity Test in Colorectal Cancer

ABSTRACT

PURPOSE: Colorectal cancers have been known to be refractory to chemotherapy in the past decades. Recently, novel agents have been developed and various data have shown an improved response rate and a survival benefit. However, considerable heterogeneity exists between cancers of the same tissue type, including colorectal cancer. Thus, Individualized chemotherapy that is tailored specifically to the characteristics of the tumor is necessary for an improved clinical outcome. RESULTS: We evaluate the chemosensitivity of colorectal cancer to standard drugs (5-FU, oxaliplatin, and irinotecan) and to drugs used for other cancers (mitomycin, paclitaxel, and gemcitabine) by using Adenosine-triphosphate-based chemotherapy response assay (ATP-CRA). RESULTS: The degree of in-vitro response to a single anticancer medication was highest for 5-FU. According to stages, 5-FU is the most sensitive chemotherapeutic agent in Duke's B, irinotecan in Duke's C, and 5-FU in Duke's D patients. With tumor location, irinotecan is most sensitive in colon cancers and 5-FU in rectal cancers. The effect of treatment is superior in the test-guided therapy group in Duke's D colorectal cancer patients. CONCLUSIONS: Chemosensitivity tests may be useful in selecting optimum drugs for patient who require chemotherapy. However, the results of this study do not strongly support the usefulness of this assay; further studies with a sufficient number of cases and an extended observation period are ongoing.