Similar to the observation among males, there was a marked decrease (46%) in the incidence of colorectal cancer in the 30–34 years group in last two decades (Table 1). The present study shows that the ASR of colorectal cancer in Hong Kong increased in the period from 1983 to 2006.

CH5424802 However, the increase was mainly among the male population. The ASR of colorectal cancer in females peaked in 1994 and declined in the past decade. The trends of colorectal cancer differ in different countries. However, the risk of colorectal cancer was higher and increasing among males, but stable or decreasing among females in most countries. In more detailed analysis of our local data, the increase was noted only in those above 60 years of age in males and those above 70 years of age in females. The rise was much higher among males than females. A gender difference and rising risk in the older, but not young population were noted also in other developed and Asian countries.6,7 The distribution of colorectal cancer was not examined in the present NVP-LDE225 study, but it was found that the decrease in colorectal cancer in women and the young population is mainly due to a decrease in colon cancer rather than rectal cancer when the data were examined again in the reviewing process. As there was a tendency towards right-sided lesions in the older population,13 and there

was an increasing proportion of colorectal cancer in the older population recently, this may explain the right-shift of colorectal neoplasm observed in a local study.14 The westernized diet, which is high in fat and low in fiber, is found to be associated with colorectal cancer in many epidemiological studies.15–19 This was further confirmed in a cohort study using cluster analysis. In the present study, a micronutrient-rich, low fat, and high-fiber food pattern was found to be associated with

lower risk of colorectal cancer.20 The Hong Kong population selleck inhibitor adopted a westernized lifestyle early in the past century with decreased intake in vegetables and fruits, but increased consumption of processed meat, fat, beer and liquor. In a local telephone study, only 15% to 21% of respondents consumed fruit at least twice a day, about 50% consumed vegetable at least twice a day and about 40% ate high fat food more than once a week.21 This may explain the overall increase in ASR locally. However, it cannot explain the decreasing risk of colorectal cancer in the younger age groups, nor the discrepancy in the ASR of men and women. Instead greater screening use in women, who are in general more health conscious, leading to greater detection and removal of neoplastic polyps may be a possible reason of the latter observation. However, concrete data are not available to support this hypothesis. Waist circumference and body mass index are associated with increased risk of colorectal cancer.