DPYD and urinary bladder cancer: Actually, uracil/tegafur (UFT), which is a 5-FU-based agent, has been shown to be effective in cases of low-grade non-muscle-invasive bladder cancer and S-1, a novel 5-FU-based agent with a strong DPD inhibitor, has a significant response compared to UFT in bladder cancer with a high level of DPD [5, 6].