“…First we should consider the most frequent site of SPDC. In Japan the most frequent site of SPDC is the stomach, followed by the colon and rectum, [4][5][6]11 whereas in China and Taiwan the most frequent site is the upper aerodigestive area, 2,3,10 and in southern Europe the most frequent site is the colon. 13 Second, we should attempt to examine asymptomatic patients.…”