To provide a method for determining the sensitivity of a patient to irinotecan, SN-38, and/or a salt thereof, which method can determine the therapeutic response of the patient and to provide a novel cancer therapeutic means employing the method.The method for determining the sensitivity of a subject to irinotecan, SN-38, and/or a salt thereof includes measuring the expression levels of AMD1 gene, CTSC gene, EIF1AX gene, C12orf30 gene, DDX54 gene, PTPN2 gene, and TBX3 gene in a specimen, and calculating the best tumor response rate (%), overall survival (days), or progression-free survival (days) from formulas (1) to (3).
