Disclosed are a cancer marker-detecting composition comprising an agent for measuring an mRNA or protein expression level of eIF3m, a cancer diagnosis kit comprising the same, a method for detecting an eIF3m polynucleotide or protein by treating a biological specimen with the agent to detect a substance binding specifically to the agent and quantitatively comparing the substance between a subject and a normal control, and a method for the treatment and prevention of cancer comprising an agent for down-regulating the expression of an eIF3m polynucleotide or protein.