8% vs 53.8%), but there was a higher proportion of proximal adenoma in females (36.2% vs 41%) and synchronous adenoma in males (9% vs 5.2%). A total of 206 male and 124 female patients had CRC (Table 5), with males having a higher incidence than females (3.5% vs 2.4%). The distribution pattern was comparable in both sex groups; distal CRC accounted for 56.3% and 57.3% of all the CRC in male and Metformin molecular weight female patients,

respectively; while proximal CRC accounted for 43.2% and 41.1% in male and female patients, respectively. Compared with young patients, elderly patients had a 2.7-fold increase in the incidence of colorectal adenoma (12.9% vs 4.7%). Overall, the distribution pattern was similar in both age groups; for elderly patients, Natural Product Library the proportion of distal adenoma slightly decreased from 55.9% in young patients (< 50 years) to 54%, while the proportion of

proximal adenoma slightly increased from 37.4% in young patients to 38.1% in elderly patients. The proportion of synchronous adenoma remained relatively static, between 6.7% and 8.4% (Table 6). CRC was observed in 69 young patients and 261 elderly patients, which meant that elderly patients had a 3.1-fold increase in the incidence of CRC. There was a trend towards more proximal CRC in elderly patients (Table 7), although the analysis showed that a shift towards increasing proximal CRC with advanced age was not statistically significant. Traditionally, CRC has been considered a common GI malignancy in Western countries.

However, with the dramatic economic development in China over the past few decades, the incidence of CRC has been steadily increasing. Nevertheless, relatively few epidemiological and clinical CRC studies in Chinese patients have been reported; however, worldwide, 26% of patients with CRC are of Chinese origin. Therefore, it is critical to assess the epidemiology of CRC in the Chinese population. The present study, from a tertiary hospital, finds some interesting trends in colorectal adenoma and CRC in Chinese patients in Shanghai. It was found that there was a non-significant increase in the proportion of left-sided MCE colorectal adenoma and CRC with a non-significant decrease in the proportion of right-sided colorectal adenoma and CRC. Although the present study is not a population-based screening study, it is a study based on the results of a total colonoscopy for more than 10 000 consecutive patients; therefore, we could precisely locate the sites of colorectal adenoma and CRC. In addition, the only investigative method we used was total colonoscopy, so the risk of missing adenoma or CRC by other methods, like double-contrast barium enema or flexible sigmoidoscopy, was greatly reduced. By summarizing the data of 11 025 consecutive patients, this study provides some important information about CRC in our local population; first, the incidence of adenoma and CRC was found to be 9.