Moreover, the distribution pattern of colorectal adenoma and CRC among Chinese
patients is different from that of Western patients, and more colorectal lesions were located in the distal part of colon. The mean age of diagnosis of distal or proximal CRC was not significantly different between males and females (distal CRC: 61.7 vs 58.8 years, P = 0.199; proximal CRC: 60 vs 62.5 years, P = 0.281, respectively). Overall, the age of patients with distal or proximal CRC was not significantly different (60.6 vs 60.9 years, P = 0.816). DAPT Our data also show that left-sided CRC was prevalent in both young and elderly patients (Table 7). This is not in line with some reports, which demonstrated that right-sided CRC is predominant in elderly people.13,22 Since the proximal shift reported by Ottenheimer et al. in 1955,23 some studies, mainly US studies, have suggested a distal-to-proximal shift of colorectal adenoma and/or CRC over the past few decades,4–9 whereas others have shown no change in colorectal lesion distribution.10–14 So it is still controversial whether there has been a shift in the anatomic distribution of CRC with time. Interestingly, several recent studies all suggested that a proximal shift in the subsite distribution of CRC occurred in Japan. Takada et al.19
analyzed the time trend of CRC in Japan between 1974 and 1994, Pictilisib concentration and found there was an increase in the percentage of right-sided colon cancer, together with a continuous decline in the percentage of rectal cancer in both sexes at all ages. Toyoda et al.18 showed that the age-adjusted incidence rates of right colon cancer among men and women increased after reviewing the data from the Osaka Cancer Registry between 1974 and 2003. Yamaji et al.17 examined a total of 23 444 consecutive, asymptomatic Japanese who underwent total colonoscopy and found that adenomas
on the right-side colon increased with aging. On the contrary, a few Asian studies, based on the Chinese population, 上海皓元 did not confirm the left-to-right shift of CRC, for example, Huang and co-workers16 investigated the time trends in subsite distribution and the incidence rate of CRC among Chinese in Singapore between 1968 and 1992; in that study, it was revealed that although the incidence rates have increased greatly, no distal-to-proximal shift was observed among ethnic Chinese in Singapore over the past 25 years. Goh and colleagues also confirmed that the majority of colorectal tumors were located in the left side of colon in 3404 patients undergoing colonoscopy from 1999 to 2003,15 and the majority of those patients were Chinese. The results of the present study are consistent with those Chinese population-based Asian studies and clearly indicate that such left-to-right shifts had not occurred in Chinese yet; moreover, 54.